MONTHLY REVIEW
Published
by the
American Electroplaters Society
Publication and Editorial Office
3040 Diversy Ave., Chicago
VOL.
XVII MAY, 1930 No. 5
EDITORIAL
If you want a better understanding of the practice of electrochemistry;
And
you want to participate in a real program of progress in your profession;
And
you are really a seeker of knowledge and truth about plating practice
and theory; and would know what the wisest and best men in electro-plating
industry have taught in the past year;
And are interested in the mysteries
of this profession and its evolution to perfection;
And it is your desire to extend your mental vision and
discover new things in plating art, developing a greater desire to
serve your fellow workers;
And
logic and reason appeal to you, you love truth, despise error and hypocrisy;
why do you not join the American ElectroPlaters Society, and
if you are a member, why not attend meetings regularly? The above mentioned
society seeks to impress its members with above philosophy, by thoughts
and words; it is the apostle of liberty from plating mysteries, and
no one who belongs to this society and attends its meetings can long
remain
idle, or ignorant, but will become strong and confident in ability.
If
not a member join now. If you are a member attend its Branch and Annual
Meetings, and enjoy its benefits.
DOING THINGS FOR THE ELECTRO-PLATING
INDUSTRY
By Charles H. Proctor
Read at Chicago Branch, January,
1930
In October last
I was very much interested in the Publishers’ Page
of “Metals and Alloys,” the short article under the caption
of “Let’s Have Your Views.” The first issue of this
excellent publication appeared in July.
Abstracting from
the October issue, I was much interested in the following statement
gleaned from results
of interviews had with representative
men at several conventions and other personal interviews by a representative
of “Metals and Alloys,” viz:
“While all the encouraging and
complimentary things said to us in these interviews were welcome and
decidedly cheering, we valued even more,
some of the intelligent criticisms that various people took the trouble
to present to us in detail.
“The most frequent
criticism was a suggestion that we steer clear of making the paper
too ‘technical’ and
that we devote at least a part of our space to articles interesting to
so-called ‘practical’ men
throughout the metallurgical industries such as foundry men, electro-platers,
etc.
“We intend to
profit by these suggestions and have already taken steps to secure
such material because we feel that ‘Metals and
Alloys’ should
have something to say to all types of people having any interest in metallurgy
and the use of metallurgical products.”
“We have had
enough experience in selling ‘advertising’ in
other technical publications to realize that the average advertising
manager instinctively shies at a paper which appears to him as being
extremely technical, or as he more usually puts it ‘highbrow.”
The
reason for my writing this paper is for the specific purpose of eliminating
from electro-plating publications and from the electro-plating industry
and from the American Electro-Platers’ Society, a lot of such “highbrow” papers,
technical, if you so desire to call them, which tell you all about the
theory of doing things but tells you nothing about producing results
on a commercial economic production basis which after all means “practical” results
in the fullest measure.
Theory is but
thought until one is enabled to put the thought, the theory, into commercial
practical results or production.
If you do not believe
so go and talk to your plant manager, to your superintendent and commence
to theorize as to how you think you can do things that you elaborate
on. When he wishes to know whether you can produce the results you have
outlined to him, you tell him no, but you have the theory that it can
be done; he will politely tell you “We want results, not theory,
you know.” This is absolutely true in the electro-plating industry.
You must know how to do things and how to produce results wanted, at
a minimum of cost, and if you cannot produce the results then some one
else will fill your position who can do what you cannot do. These are
cold commercial facts that all the theory in the world cannot eliminate
from commercial production at a minimum of cost.
We often hear
that the chemist will eliminate the electro-plater due to his superior
knowledge
of the chemistry of the electroplating solution
and its control. On November 23rd last I had the pleasure of presenting
a paper before the New York Branch of the American Electro-Platers’ Society,
entitled: “Taking the Bunk Out of Electro-Plating Industry” and
incidentally the electro-platers society. I anticipate that this paper
will eventually be published in the “Monthly Bulletin” of
the Society. From the ovation received after the papers presentation
it would appear to its author that its hearers were satisfied that there
is a lot of “bunk” as he outlined.
Experience, you know is
the best teacher in the world. There is nothing like experience. It
costs a lot of money some times to gain practical
experience, and experience that cost most is longest to be remembered,
but after all the cost is worth while when the knowledge has been gained
that can be put to commercial results and production.
If we summarize
the results in defining what a successful modern electro-plater should
know then this is the answer:
(a) He should have learned thoroughly
the art of electro-plating in all its details, be able to deposit any
commercial metal and apply any chemical
finish on any metal.
(b) He should be able to analyze his plating solutions
chemically and to know what plating formula will produce the maximum
results under intensive
commercial production at a minimum of cost. Chemical knowledge and
control of his plating will enable him to produce constant results every
day,
under known conditions and when analysis of solution does not overcome
problem then experience gained through years of application will tell
him what further additions must be made to his solutions to correct
them when the deposit goes wrong and therefore make them right.
When pitting
of nickel deposits occur, when peeling of the deposits results, which
all too frequently is laid at the door of the manufacturers of
metal cleaners, and when analysis of the solution does not tell you “why” these
problems occur or how they occur, but you have learned that such results
are due to hydrogen in excess which results from solutions of high metal
concentration and high current densities now used in intensive production
of plated products at a minimum of time, then you certainly must know
what to do.
To give you a
basic idea as to what is required to control hydrogen conditions in
high density nickel solutions operated at temperatures
up to 130 deg.
Fahr., firms that manufacture automobile bumpers and auto radiator shells,
use as much as 30 barrels of 25 volume hydrogen peroxide per month, others
use an equivalent amount of sodium perborate which they convert to hydrogen
peroxide themselves. In copper plating high carbon steel from high density
copper cyanide solution pitting and pealing of the copper deposit, can
be traced to the same evil factor “hydrogen” which I once
termed the “devil” of the plating solution.
(c) He should
study Faraday’s and Ohm’s Laws so that he can
determine what current densities are best adapted for the various metal
deposits he must produce. Electrical control of the plating solution
and the plated deposit is even more essential than analysis of the plating
solution if he desires to reproduce continuously “standard” plated
deposits of known thickness he must know to a certainty the voltage,
the amperage and the time factor that is required to maintain such results.
Guess work and rule of thumb methods will then be entirely eliminated
and a man with such knowledge as outlined in a, b, and c can then be
considered as a truly modern electroplater. Chemists and metallurgists
and engineers, too, realize that without the knowledge gained from years
of practical experience in electro-plating methods they are but as “figure-heads”
and “highbrows” as
I have already referred to in he outline of this paper.
Doing things
for the electro-plating industry then is the essential factor for commercial
results. I always enjoy listening to our good friend and
wise counsellor, Dr. Oliver P. Watts of the University of Wisconsin.
When you follow carefully what he explains to you in his interesting
talks you will make note that he always says “You can do this.” He
does not hand you a promissory note such as many orators do when they
address you on electro-plating matters, when they state that “If
you can do this or that, then, of course, you can accomplish a purpose,” but
when “if” is attached to “you can,” a hundred
chances to one is that what the author has in his mind as a theory cannot
be done in practice.
I should prefer
to listen to more of the Oliver P. Watts type of men’s
interesting talks in his quiet way, than to all the presumptuous that
talk before the electro-platers society and when they are through find
that the things they elaborate on cannot be done. We are interested in
doing things for the electro-plating industry. Papers presented should
teach us this.
Self-praise, I know, is no recommendation. It belongs to the demagogue
class I spoke of a few weeks ago in Philadelphia at the annual educational
session and banquet of the Philadelphia Branch. But when a man has been
connected with the electroplating industry for nearly forty years as
I have, his visions of other days carries him backwards and he tries
to discern through the mist of elapsed years “what” he has
done for the good of the cause he has the honor to represent. For twenty
years I have been using my pen for the good of the cause and doing the
things for the plater and the industry of which they are an integral
part.
It is not necessary
to re-state the fighting chance I took several years ago single handed
to prevent control of the cadmium plating
industry
which has become of great commercial importance in America, when I established
prior art through the publication of the Russell and Woodrich patent
of 1849 and also the splendid article on
“The Electro Deposition of Cadmium” by the late Emmanuel
Blassett, Jr., as published in The Metal Industry, December, 1911, which
re-established
prior art and enables any one to operate a cadmium plating solution commercially
without violation of any succeeding patent. There exists today only one
real patent that can be considered as a valid factor and that factor
is an anode that contains as the controlling factor metallic mercury
on the basis of 98.99 per cent cadmium and 2 to 1 per cent mercury.
I
have fought my way through the maize of chromium plating with the same
weapons, public opinion, as I had previously done with cadmium, fearless
and free in the belief that I was right in defending commercial chromium
plating established in the expired patent of Placet and Bonnet. Establishing,
as we have defined it, prior art of the work of Carveth and Curry who
were in accord with the findings of Placet and Bonnet and substantiated
their claims that commercial chromic acid could be used in connection
with sulphuric acid as the sulphate factor and bright lustrous chromium
deposits resulted that should eventually have great commercial values,
of the work of Sargent financed by Dr. Bancroft and Carveth and Curry,
resulting in the chromium solution with minor modifications that is in
use all over the United States today.
More
than four years ago I mentioned to many of my friends who followed
my ideas covering a distinctive
chromium plating solution based on Sargent’s
original solution, that I would for their interests and the interests
of commercial chromium plating make every effort to obtain a patent on
a distinctive chromium solution which would protect their interests against
encroachment and my company, who I have the honor to represent at this
meeting, as well as mine. The claims have been allowed covering the solution
and anodes, your protection is mine, and all my friends included. This
is “doing” things for the electro-plating industry. A year
ago this time I presented a paper covering a duo-deposit of duo zinc
and tin for the benefit of the electro-plating industry and gave
all details as to plating solution, etc., and its control. When you
see a radio unit that is mounted on a steel plated base and which has
a color
approaching scratch-brushed silver in whiteness and lustre you will
know then it is a duo-zinc and tin deposit that is produced at less than
half
the cost of straight cadmium deposits.
As a
solution of the problem of high cost of cadmium and still maintain
the maximum
resistance against
rust and atmospheric oxidation of malleable
iron and gray iron and steel products, the Roessler & Hasslacher
Chemical Company introduced in large eastern plant a duo-deposit of cadmium,
zinc and mercury, 50 per cent cadmium, 48 per cent zinc and 2 per cent
mercury. The solution itself approximating the same equivalent basis.
The firm in question plates twelve tons of small parts of conduit fittings
made from malleable iron and steel per day. The cost of the anode is
slightly more than one half of that of an anode made from pure cadmium,
when you consider the difference in the atomic weight of cadmium and
zinc, this special anode does not cost half as much as cadmium but the
rust resistance is much greater.
You
can realize the enormous saving that results to the firm in question
in the cost of a year’s time by
using this new alloy.
Another innovation in doing things by the company that employs me for
the electro-plating industry, they have put out a new alloy and solution
which we have given the name of “Durobrite.” It is really
due to a high zinc-low cadmium anode, 90 per cent zinc, 10 per cent cadmium.
In this unusual deposit it would appear that the cadmium acts as a colloidal
metal factor resulting in the bright lustre finish elaborated on.
Doing
things for the electro-plating industry resulted in a distinctive bright
white lustre deposited metal for distinctive metal shoe buckles
attached to white leather shoes which will be all the vogue in women’s
footwear this summer. For years the chrome alum tanned white shoe leathers
have attacked all electro-plated deposits applied to low brass shoe buckles.
Cut steel, silver nickel, any metal that gave a finish comparable to
the white leather of the shoe was attacked and disintegrated by the action
of the chrome alum in the leather and moisture of the atmosphere. Two
well known firms in the east have copyrighted as trademarks the names
“Tarno” and “Plateen” finish.
The finish was introduced by the author of this paper and consists of
a white bright lustre electro tin plated deposit obtained from the electro
tin plated solution given to you in Chicago a year ago.
Burnishing in
oscillating burnishing barrels, better known in the east as tumbling
barrels, with plenty of steel balls and “burnishine” burnishing
soap solution are the lustre producing factors.
Doing things
for the plating industry resulted in two high density nickel and copper
cyanide solutions
being introduced by the author for the benefit
of the automotive industry, that wanted such solutions which could be
operated at a minimum-of 50 amperes per square foot of surface area.
In experiments carried out at the Research Laboratories of the company
that employs me at Perth Amboy, N. J., with these solutions, current
densities have been carried as high as 100 amperes per square foot of
surface area. Sections of automobile bumpers plated in such solutions
for a total of 19 minutes, including three minutes in our standard chromium
solution with two buffings included applied to the copper deposit and
final nickel deposit, the quadruple deposits consisting of nickel, copper,
nickel and chromium, when exposed to the action of a standard 20 per
cent salt spray test solution, the break down showed that rust spots
did not occur until after five hundred hours exposure to the test.
What I have elaborated on in this paper should I believe be my answer
to “Doing Things for the Electro-Plating Industry.”
In
a later paper I shall give all solution details covering the deposits
mentioned
in this paper, so that “Doing things” for the electro-plating
industry will be more complete.
Some of the papers
written years ago by the writer and which today have all the hall marks
of today’s modernism
in the electroplating industry are:
“A Simple Method
of Regulating Anode Surfaces in the Plating Bath,” illustrated
with drawings.“The Metal Industry, July, 1910.
“The Rapid Deposition
of Nickel by Continuous Filtration Using Felt Bags and a Mechanical
Pumping Device.” Some time in 1908 (exact
date is at present lost).
“Some Methods
Used by Electro-Platers to Produce Bright Nickel Deposits.” (Cadmium
was first mentioned in this article.) The Metal Industry, January, 1916.
“Speeding Up
the Electro Deposit.” (The evolution of the
single nickel salts in still and mechanical plating solutions. ) The
Metal Industry,
February, 1916.
“How We Can Best
Adopt ‘Standardization’ for Plating
Solutions and Products in Individual Plants.” The Metal Industry,
July, 1919.
“American Electro-Platers’ Society
and the Manufacturer., The Metal Industry, August, 1920.
“Guaranteed Electro-Plating.” A
plea for better electro-plate products in the automotive and other
industries that should carry the
guarantee
of its wearing qualities by the manufacturer. The Metal Industry, August,
1923.
It is interesting
to note that the above title covered an address made at the convention
of the American ElectroPlaters’ Society
in Providence, R. I., July 2 to 5, 1923, and contained an important paragraph
which
can certainly be considered modern in this year of grace, 1930, and is
as follows:
“It is my desire
that this 1923 convention of the American Electro-platers, Society
go on record in support of better plated products, which will
be more enduring under the rigid service that all plated products
must endure under our modern conditions, and that the application of
electro-plated surfaces shall be improved so that the maximum of wear
can be assured to the consumer who must pay the price of poorly plated
defective products.”
Nearly seven
years ago and the statement still emphasizes “Doing
Things for the Electro-Plating Industry.”
THE CONTROL OF H ION CONCENTRATIONS
IN SOLUTIONS FOR NICKEL DEPOSITION
By Dr. A. K. Graham Read at Phil.
Annual Meet, November, 1929
DR. A. KENNETH
GRAHAM: As you probably recall, the earliest references to the control
of acidity in nickel solutions relate how litmus paper
was used to test that acidity. And we now know that merely indicated
that the solution was either acid or alkaline to the indicator, litmus.
About
1914, the American Hardware started some work, and they developed a
method of controlling the acidity of nickel solutions by titrating
that solution with standard acid and an indicator
I think the indicator
used was sodium alizer and sulphonate and they successfully controlled
their solution by that method. Between 1914 and about 1922, Mr. Sizelove had done considerable work
on the analysis of plating solutions, and one of the things that he
did- was to develop a method of control of the acidity in nickel solutions
by titrating that solution with acid and ethyl red as an indicator.
The
two methods are quite similar. Mr. Sizelove expressed his results rather
ingeniously and I will refer to that later, but the cardinal fact is
that both concerns independently, or both people independently by those
methods were able to successfully control their nickel solutions and
produce good work under practical conditions.
About 1924, Mr.
Thompson, of the Bureau of Standards, suggested the use of Brome cresol
purple
as an indicator, and that that be used in connection
with standard acid in titrating acidity in nickel solutions. To the best
of my knowledge, that only enjoyed a limited application. For no reason,
apparently, the other method only enjoyed limited applications. I might
suggest that the real reason for that is probably the fact that from
1914 to 1924, the platers of the country knew considerably less about
analysis of plating solutions than they know today. Consequently, they
couldn’t avail themselves of the information that was at their
disposal. In addition to that, in later years the titration method used
by some of the men I have referred to gave a result which could not be
checked or would not give agreement with other methods of controlling
acidity, such as the pH control method. There was lack of agreement.
That also probably mitigated against the adoption of the titration method
for control of these solutions.
It was about
1922 that Thompson at the Bureau of Standards advocated the use of
colorimetric standards for the
control of the pH of nickel
solutions, using brome cresol purple as the indicator. Since that time,
that method has enjoyed general use and popularity. It has served to
give a much more satisfactory control of the hydrogen ion concentration
of the nickel solutions than anything heretofore, and it was easily learned
by the plater, and consequently has grown in favor and is now more or
less generally used. As we gathered more information on the application
of this method, we found that there were some variations that couldn’t
be explained between results in different plants, and in imparting knowledge
as to how you best operated and how another man attempted to reproduce
your results. About 1924 or a little later, LaMare of Columbia University
at a meeting of the American Electro-Chemical Society, recommended the
use of quinhydrone for the measurement of pH by an electrometric method,
and Mr. Youdon, of the Boyce-Thompson Institute, of Yonkers, N. Y., was
applying this method in the testing of the pH of soils.
The method was
taken over by Mr. Pitchener, of the American Chain Co. and applied
to nickel solutions.
Since that time, a number of methods
of measuring the pH of nickel solutions, electrometrically, using quinhydrone
have been developed and have even
been put in use in plants. The colorimetric method has the advantage
of being rapid, only requiring a .small expenditure of money for the
equipment, and easily learned. The electrometric method is capable
of giving more accurate results, and yet it does require more expensive
equipment, and a little more technique in operating.
With the development of these two colorimetric methods jointly, it
became apparent that there was a variation in the results obtained
by the two
methods on any one solution. That led to the investigation which Dr.
Blum and some others completed last year which was published in the
spring meeting of the American Electro-Chemical Society, at which time
it was
shown that certain things gave errors by the colorimetric method which
by the electrometric method were eliminated to a large degree, and
the general conclusions were that for research work where you wanted
to record
the absolute pH value of nickel solutions, that the electrometric method
with quinhydrone gave the most satisfactory results for ordinary operation.
However, for plant control the colorimetric method sometimes was a
very satisfactory means of controlling the pH, but we should recognize
in
using that method that the values given are somewhat higher numerically
than the absolute true values which are recorded by the electrometric
method, approximately five tenths of a pH unit higher for the general
run of solutions.
Now in that paper, a number of solutions of the more
or less common compositions have been studied and the actual salt error,
or deviation of the colorimetric
measurement from the electrometric measurement have been recorded there
and can be consulted, if need be;: That study focussed attention on
the accuracy of pH measurements. It also focussed attention on the fact
that
in the average plating operation, the pH will vary within certain limits.
Now
we have recommended for a number of years among ourselves (I am speaking
of the old platers) a value of pH of about 5.8 for the ordinary type
of cold nickel solution in still plating, and yet we realize that if
that pH dropped to 5.6 or if it should go up to 6.0, we get satisfactory
nickel plating. If it goes much below 5.6, we have trouble due to too
great an acidity; if it goes much above 6.0, we have trouble due to
too great an alkalinity; the deposit might become dark, and so on. But
we
have a limit on either side of 5.8 of approximately four to five tenths
of a pH unit within which we can satisfactorily operate.
Now for plant
control, therefore, there is no use in going to any great accuracy
or trying to define things more closely than that when we realize
that that is what we are actually doing and getting away with it satisfactorily.
Now
in recommending the correction of the acidity of the nickel solution,
where you measure the pH and find it to be about 5.3, as an example,
and you want it to be 5.8, the most that you can do is to tell the party
concerned that they must add a certain amount of ammonia, preferably
ammonia (you can add other things) or of a base of some kind, nickel
carbonate, nickel oxide, but add a certain amount of hydroxide to raise
that pH from 5.3 to the desired value of 5.8. You can’t tell them
how much. The quantity depends entirely on the composition of your solution,
and that varies in each different plant, and in different uses, so that
you can only tell him to add the material until after additions the solution,
tested with, say, a colorimetric set, will give a pH reading of about
5.8. Now that means a cut and try method. After you operate a solution
in your own plant for a period of time, you become so acquainted with
that solution and the buff characteristics which determine how much acid
or alkali are needed to change a given value of pH, that you can say, “Well,
to change it from 5.3 to 5.8, I have to add so many c.c.’s of concentrated
ammonia per gallon.“You might learn from experience. But the fact
remains that you usually have to experiment to be certain, and test it
afterwards.
Now on a large tank, where you have a large automatic installation
with say a 10,000 gallon nickel solution, it is some job to add ammonia
and
stir it in the entire solution and measure the pH and be sure you are
up to the value you want. It is time consuming. On the other hand,
if you had a means of actually measuring not only the pH, but the quantity
of acid or alkali required to make that adjustment, at one and the
same
time, you would make it much simpler and it would be much more satisfactory.
The
titration method offers this advantage. It was because of the fact
that there was reported disagreement between control by the titration
method and the colorimetric method that the titration method was again
investigated. It was found that by the method suggested by Mr. Sizelove,
using methyl red and standard acid, that one was able to correct the
pH of a solution to well within two-tenths of a pH unit, which is plenty
good enough. Certainly comparable to any colorimetric method as far
as
adjustment of pH. At the same time, in making the titration which enables
you to correct the solution to that pH value, you are determining the
amount of acid or alkali required to actually effect that change in
your solution. To illustrate the point, take our solution with a pH of
5.3.
We titrate it with methyl red and we might find that it is slightly
alkaline to methyl red and it might be equivalent in alkalinity to about
1 c.c.
of concentrated commercial ammonium hydroxide per gallon of solution.
They are the units in which Mr. Sizelove expressed it, and they are
very satisfactory for our use.
Now if we want
to operate at 5.8 pH instead of 5.3, we must lave it more alkaline,
and if we once determine how many
c.c.’s of ammonia were
required in a solution, when titrated with methyl red to give a pH reading
of 5.8 on a colorimetric instrument, we have a value in terms of the
cubic centimeters of ammonia per gallon of solution which can be used
as a standard alkalinity for controlling that solution. It has been found,
in certain plants, that if we keep our solutions for still plating where
the nickel is about 3 ounces per gallon, the ammonium chloride about
2 ounces, boric acid about 2 ounces per gallon, and about 3 1/2 c.c.
of commercial ammonium hydroxide per gallon—in other words, the
alkalinity of methyl red corresponds to that amount per gallon, of ammonia—that
it gives satisfactory results. On the other hand, if barrel plating from
that same solution, the alkalinity should be greater, and if once determined
that for the most satisfactory degree of acidity in barrel plating that
the alkalinity should be about 6 c.c. of concentrated ammonia when titrated
with methyl red, that would be the value used in maintaining that solution.
Now
to illustrate a little further, suppose you wanted to put this method
into control. You would first take your solution and adjust it empirically
by the addition of acid or alkali until you get it to be what you would
consider to be the best value of acidity so that you are getting satisfactory
work. That corresponds to the operating pH you normally use. You can
measure it on the colorimetric set if you want to determine it. Having
once done that, then titrate your solution as described in the Metal
Industry by Mr. Sizelove, in about 1922, and in a recent article this
month then titrate it with methyl red and standard acid and determine
what its alkalinity to methyl red is, in terms of c.c.’s of commercial
ammonium hydroxide per gallon of- solution. If that corresponds to 6
c.c.’s, as it would in the solution I referred to for barrel plating,
that solution is satisfactory, and it tells you that that is the alkalinity
you want to control or the value of alkalinity which you wanted to control.
Now
suppose your solution goes off. It becomes too alkaline. When you titrate
it to methyl red again you will probably have 8 c.c.’s
of ammonia per gallon, indicated by the titration. It means that you
have to add a certain amount of acid to bring it back to a value corresponding
to 6 which is the one that you want to control. Now it has also been
shown by Mr. Sizelove that commercial sulphuric acid, CP, one c.c. of
that, is equivalent to 2 1/2c.c.’s of commercial ammonium hydroxide,
so that if you want to reduce the alkalinity of your solution about 2
1/2 c.c.’s of ammonia, you can add one c.c. of CP, concentrated
sulphuric acid, to a gallon and that will make the correct neutralization.
Now I
just want to point out that while the titration method originally was
not generally adopted because of the fact that as platers we didn’t
know as much about analysis as we now know, I can’t help but emphasize
too strongly that here is a method which now with your knowledge of analysis
which you have gained and which a number of you are using, it is entirely
possible to control your solution entirely by a titration method with
acid as an indicator, and at the same time, when you are doing that,
you are determining not only what the pH of your solution is within the
satisfactory operating limits—you do that simultaneously—but
you are determining the amount of acid or alkali which you have to have
in order to correct the solution to that proper pH value. (Applause.)
CHAIRMAN
LUKENS: Is there any discussion? Are there any questions ? It is certainly
gratifying to find that so few of you have problems in determining
the H Ion concentrations of nickel solutions. I hope my assumption
is correct.
MR. JOSEPH MUIR:
Taking the pH reading of a nickel solution, if you get a color reaction
there that doesn’t correspond to any
of the tubes on your scale from 5.2 to 5.8, what would be the cause of
that? Contamination
of the nickel solution?
DR. GRAHAM: I presume you are referring to the
brome cresol purple. If it is beyond the purple, it is more alkaline
and would not be covered
by the scale, but you would know it is too alkaline. On the other hand,
if it is below 5.2, it is more yellow than the lowest tube you have,
and you know it is more acidy. So the thing to do would be to make
an addition of either acid or alkali to bring it within the range, and
then
you would know how much to adjust.
MR. MUIR: This was a deep blue reaction.
I imagine it was some contamination.
DR.
GRAHAM: If it was a deep blue, it was too alkaline, way beyond the
value indicated by the 5.8 tube.
MR. MUIR: I attempted
to adjust the solution but it didn’t make
any change in the plating.
DR. GRAHAM: Ordinarily it would be due to that
alone. If you-took a small portion of that in a beaker, and added a
lot of acid, you should be able
to throw it way over on the yellow side.
MR. MUIR: I made
it, and brought it back to 5.8. Ordinarily you would think you would
get satisfactory
results, but I didn’t find the
same conditions. It gave me dark streaks on the plating, so perhaps there
is contamination there.
DR. GRAHAM: Dark streaks can be caused by other
things. Ordinarily, the dark streaks you get from the hydrogen concentration
are due to two things.
Sometimes when the solution is too acidy you might get streaks, but
usually they are bright. But if you have too much current with it, it
could look
like a dark deposit. But if your solution is too alkaline, way above
the 5.8 tube, it gives you a dark nickel. So that would give you generally
a dark chrome over it and on the edges there might be a little burned
deposit. However, you can have zinc and cadmium in solution as impurities,
and they will give you dark streaks.
MR. MUIR: How about copper?
DR. GRAHAM: Copper will give you a bluish
nickel before it will give you dark streaks. Zinc and cadmium are more
likely.
MR. KEMP: In testing
the plating of nickel, would it be out of the ordinary to take distilled
water, boiling, and place the work in there a half
hour, and leave it in the same water for six hours afterwards? Should
that affect the nickel? We have tried that and found our work was pitted.
Now what is the cause of that? It was buffed and nickel plated.
DR. GRAHAM:
I am not certain that I got your explanation correctly, but I understand
that you are taking the nickel plated article and putting
it in distilled water, boiling it and holding it there a half hour,
and you get some sort of spots.
MR. KEMP: No. We leave it cool off in the
same water six hours, take it out, and there are different spots in
there
DR. GRAHAM: Are you sure
you have plenty of nickel on there ?
MR. KEMP:
That is the question. We have stripped the nickel and found it very
good.
DR. GRAHAM: How much did you have on?
MR. KEMP: I haven’t that with
me. We deposited nickel on there from an hour and a half to two hours,
very good nickel. We had other
articles in the same tank that withstood all the tests they could put
to it, but these things are instruments that won’t stand the test
as far as that is concerned.
DR. GRAHAM: I
am afraid I can’t answer
the question.
MR. GEBERT:
Mr. Chairman, I might say that in our work on getting up methods, somebody
quite a few years brought up a point that if you spray
distilled water instead of salt solution in your spray, it will work
almost as fast. We didn’t find it so. The distilled water took
a considerably longer time than 20% salt solution. We found even with
distilled water the spots would come up if they were through to the steel,
and it would have been shown up with the ferricyanide test. It would
have shown up. In other words, pits through to the steel would gradually
rust the same as they would in the salt solution, and I wondered if you
didn’t have pits there, and this helped to show them up.
MR. KEMP:
We cleaned it off, and there is nickel right there, no marks or anything-else
after it is cleaned off. That is what gets me.
MR. GEBERT:
A pinhole is not visible to the eye.
MR. ROBINSON: With a
piece of cadmium plated work, in a solution with a pH point of 5.6,
is there any danger of that piece of work being attacked
by the free acid in the nickel solution?
DR. GRAHAM: Cadmium,
I think, would have sufficient solution pressure so that it would displace
nickel
just by immersion. Now the thing is,
when you start to plate cadmium in a nickel bath, if you don’t
turn the current on, practically at the same time you put the article
in the tank, or you don’t make the contact for that length of time
it is depositing nickel by immersion, and for all the nickel deposited
by immersion, an equivalent amount of cadmium will go into solution.
Now that identical condition exists in the plating of die castings, where
you have a high zinc base metal, and just the short time that it takes
for the article to cover with nickel is sufficient so that a small amount
of nickel is deposited by immersion and an equivalent quantity of zinc
will go into solution. Now, over a period of time, such nickel solutions
build up in zinc to such an extent that they have to be discarded because
they would be detrimental. I imagine the same thing would be true with
cadmium.
MR. HOFF: Might I mention in connection with that question
that the depositing of nickel on cadmium is being carried out as a commercial
operation at
the present time right here in Philadelphia at the Atwater Kent Company,
and some of the representatives from there can tell you of their success?
DR.
GRAHAM: Mr. Robinson is from Atwater Kent.
MR. HOFF: Not evading the
question, but in addition to that I think we will agree that the chromic
acid is more active on cadmium than is nickel,
and at the present time chromium coatings are being deposited on cadmium
without destroying the luster.
MR. ROBINSON: Is that deposition by immersion
detrimental to the nickel after it has made contact in the tank, that
is, after the work has made
contact in the tank?
DR. GRAHAM: I would say in ordinary operation, where
you have the batch of work cleaned, rinsed and put in the solution,
and it makes contact
the minute the hook strikes the cathode rod, that if the current conditions
are properly adjusted on your tank, that no injury would occur. However,
if that is allowed to remain in the bank for any length of time with
the current off, then you would expect the deposit to be spoiled.
CHAIRMAN
LUKENS: Dr. Graham, I extend our thanks to you and I am sure those
who see fit to try your suggestions will be well rewarded. Personally,
I am quite in accord with favoring such a method of control.
CHEMISTRY
AND ELECTRO-PLATING
A. A. Bissiri, B. S., M. A.
Read at First Annual Meeting Los Angeles Branch March 15, 1930
I feel
quite at home in this gathering because many of you are enrolled in
my chemistry class, and also because after all you also are chemists,
though only practical chemists.
Having listened to the splendid address
of your founder, Mr. Proctor, I think there is very little else I can
say to show the relation of modern
chemistry to your business. Therefore, I will limit myself to give
you very briefly my impression of what I consider is the present need
of
the electroplating industry in Los Angeles.
As was suggested by Mr. Proctor,
electroplaters must establish certain standards for their products,
which will make possible a guaranteed uniformity
of the finished product. And this will be accomplished only when electroplaters
will work hand in hand with the chemists.
Other large industries, such
as the rubber industry, the steel industry, the paper industry, and
many others, have long been placed under strict
chemical control, and as a result it has been possible for them to
progress very rapidly and to eliminate from their process the element
of guess
work.
Unfortunately the same can not be said of the electroplating
industry. .
Judging from
the few electroplating establishments I have been privileged to visit,
many are still using the unscientific method
of “rule-of
-thumb.”
Certain standard formulas are used and so long as nothing
unusual takes place everything is fine; but once in a while things
begin to go wrong
and then an attempt is made to correct such condition by adding a handful
of this or a handful of that.
This perhaps is not true of all the electroplating
establishments but is no doubt true of most of the local ones at least. This should be remedied by the help of the chemist, and since the great
majority of electroplaters could not afford the expense of hiring a
chemist, and could use him only part time, the solution can be found
in the establishment
of a co-operative laboratory. The expense of such a co-operative laboratory
could be divided among the different electroplaters according to the
amount of work done for each one. And this laboratory should include
in addition to one or more analytical chemists, a consulting chemist
who could devote some time to the careful inspection of the different
plants for the purpose of solving any problem of a chemical nature.
Such
a consulting chemist would also keep the local electroplaters well
informed of all the latest discoveries in the field of electroplating.
You may not now be convinced of the real need of a cooperative
laboratory but there is no doubt in my mind that it will, nevertheless,
become a
reality within the next few years.
I thank you.
A PANORAMIC VIEW OF THE PLATING SITUATION
Read at Chicago
Branch Annual Meeting, Jan. 18, 1930
Jacob M. Hay
Gentlemen: It is doubtful whether all of you present here
will immediately grasp the true interpretation of the above title,
which of course is
rather broad. All of you, I am sure, have realized the change which
the plating industry has undergone the past few years.
Since the advent of
chrome plate finish, now adopted by practically all of the automotive
concerns, which consume tons of the basic material
yearly, namely, chromic acid for the plating baths, much interest has
been awakened as to the condition leading to the ultimate finish.
We hear
and read a good deal on the special or trick methods of polishing and
buffing, metal cleaning, with or without current, nickel and copper
plating, some favoring cyanide copper bath and others acid copper bath,
the P. H. so and so in the nickel bath and metal ion concentration,
not saying anything about temperature, current, densities, and other
bath
ingredients which affect the conductivity of the plating bath and anode
material used. At times the writer is inclined to assume that much
of this information has put an air of mystery into the art which at times
places the plating industry in an unhealthful position. What the buyer
or the engineer wants is concrete facts. He cannot waste his time and
money in anything that does not offer some degree of guarantee after
he places the finished part on his product.
Now let us stop briefly and
analyze the situation as to the real cause for the great interest that
has been manifested in other metal finishes
which have been considered with some seriousness by the automotive
trade. The metal to which I am referring is stainless steel of the straight
chrome and chrome-nickel iron series. The latter is being sold under
the trade name KA 2. My of you are either directly or indirectly engaged
in the plating industry and I am positive in making the assertion that
you no doubt are aware of some of the facts which were directly responsible
for the interest displayed in this metal.
If you are on the service end
of your personnel whose responsibilities would bring you in contact
with the claims that are made on defective
chrome plated parts from the field, you would immediately conclude
that chrome plate finishes are far from being non tarnishable and rustproof,
the former resulting in most cases on brass parts from insufficient
coating
of nickel and porosity of the plate, and the latter condition is due
to nothing else but porous coatings of nickel and copper. If
we are to guarantee ourselves against a great number of these claims
which have
been emanating from service we must get together and standardize
the plating conditions under which the ultimate finish is obtained. I
want to emphasize with great stress at this point that in order to overcome
the unfavorable reports regarding the life of chrome plate finishes we
will have to use good salesmanship in convincing the buyer and public
of chrome finished parts that a good commercial grade of plating cannot
be done on a cut throat price basis, whether the goods in question happen
to be a suit marked at $100 or one at $25 the consumer is getting just
what he is paying for. This example may be applied to the metal finishing
trade. It is the writer’s opinion that if the jobbing plater were
to charge a legitimate price for his goods, a reasonable profit could
be made that would permit him in conducting a research laboratory on
a small scale whereby he could build up for himself a prestige and guarantee
a product as coming up to standard specifications after the goods leave
his plant.
All of this may sound like fiction to you, gentlemen, but
let me issue this warning: some day in the near future you will find
many
of the now
chrome plated parts being changed over to stainless steels of one of
the two types mentioned before. Much of this is being done at the present
time. Many of you will say that due to drawing and polishing difficulties
the use of stainless steel will be limited. To this can be said with
authority that drawing dies are being revamped to take care of any
stretcher strains, or breaks which have heretofore taken place in fabricating,
and automatic polishing and buffing machines have corrected these faulty
conditions in numerous instances.
Many of the failures on chrome plated
parts that have been submitted for your attention were due to two major
factors. The first resulting
from poor adhesion of the plated material to the base metal. This has
been corrected by making a-careful study in the cleaning and plating
operations, especially in the cleaning. There has been a marked percentage
drop in the failures of plated parts due to these particular items.
The second factor which has not been eliminated and that is causing us
some
concern is that which is due to the porosity of the successive coats
of copper nickel and chrome.
Let us analyze briefly the causes for corrosion of ferrous metals in
the unplated state. According to the acid theory carbonic acid contributes
a great deal of corrosion. The action which takes place may be expressed
by the following equation:
2 Fe + H2C O3 = 2 FeCO3 +
H2
4 FeCO3 + 10 H2O + O2 =
4 Fe(OH)3 + 4 H2C O3
It will be
noted from the above equation that iron unites with the carbonic acid
forming a ferrous salt mainly FeCO3 with hydrogen liberated which
in turn combines with any dissolved oxygen yielding water. This is
followed by the oxygen of the air combining with the soluble iron salt
to form
hydrated oxide or rust setting free carbon dioxide which is available
in making another charge in accordance with the above equation. This
action as has been stated before takes place on unplated parts. On
plated parts we also have the electro-galvanic theory which most of you
are
acquainted with. So with these two theories in mind you can readily
perceive the necessity of producing a non-porous plate.
We cannot combat this corrosion
problem if we are to continue placing on the market pitted and porous
plated parts
A few days ago the writer noted an article in one of the daily newspapers
illustrating the new method of removing snow and ice from the streets
of one of the large cities in the east. Pellets of calcium chloride were
being shovelled on the snow where it is claimed that in a short time
a brine is formed which melts the snow, making a slush, facilitating
the removal of the same. Do you realize what effect this is going to
have on plated parts of an automobile in a few weeks’ time? All
the more reason why the commercial plating of that part should be free
from porosity. These are the elements which we must combat and there
are no two ways about it.
These facts presented here, gentlemen, are worthy
of some consideration and the sooner we get down to work and improve
the quality of the plated
finish or parts which have caused any amount of grief the past two
years, the quicker you will re-establish con-fidence in the eyes of both
the
public and trade as to the much advertised merits of chrome plating,
and at the same time meet price competition with some of the newer
metals mentioned in the foregoing paragraph. I am sure that the question
is
important enough for everyone engaged in the art of electro-plating
in making a mental inventory of just what is wrong in his department.
If
it is better basic material that you need for finishing I am sure you
can convince your purchasing department in spending a cent or two more
per pound, instead of using an inferior grade of basic metal and then
eventually realize a tremendous loss due to rejection from your prospective
buyer of that part.
As we follow the writers of articles pertaining to
nickel and chromium plating, I can not help but feel that there must
be something radically
wrong with the methods of doing our work and controlling our solutions
if these writers making positive statements are right. No one has yet
made an attempt to lay down a definite law or has been able to explain
to the satisfaction of all concerned the reasons why certain failures
occur in the process of preparing and plating metallic parts for nickel
and chromium finish.
The writer of this paper will attempt to explain
some of the facts as they exist at the present time. I realize that
as time goes on we progress
and learn things that were unknown before, and we would not he worthy
to belong to this great educational society of ours if the new facts
were not brought to light.
One of the first important steps we have to
consider is the cleaning of metals for plating; so let us begin with
the cleaning solutions. Most
cleaners are made up of more or less of the same chemicals as hydrates,
oxides, phosphates, aluminum carbonate; silicates, colloidal hydroxides,
and in powdered form such as clay, ground glass, and powdered sodium
silicates.
As these compounds are supposed to have a scrubbing action
on the metal surface to be cleaned, mechanically mixed cleaners should
not be used
for they will separate and will not stay mixed in the solution as they
were intended to be. While it is true that finely divided solid particles
in suspension assist cleaning yet the clays used for the purpose contain
alumina which is sufficiently soluble in the caustic soda to form a
soluble aluminate or colloidal hydroxide which can be electrically deposited
upon the work causing serious roughness. A fused cleaner of soda ash,
tri-sodium, phosphate, sodium silicate rosenate and very little caustic
soda will always make a very good cleaner where electric cleaning is
done. So much for that. Now let us consider conditions as they exist
in every day practice.
Metals are usually drawn in the press room by punch
presses or machined upon screw machines or otherwise, the compounds
and oils used in these
operations are not soluble in the ordinary electric cleaner. Metals
of the non-ferrous parts should always be washed in a washing machine
with
caustic soda and cyanide as this cleaner will be the most effective
for washing machines. Steel and cast iron should first be washed and
then
pickled, then put into an alkaline rinse and then in hot water. After
polishing, buffing, and coloring, the parts should then be ready for
the electro-cleaning.
Care must be taken that the polishing and buffing
composition does not contain more than five per cent of organic greases.
One year ago the
writer recommended buffing composition without any organic greases,
but has found since then that five per cent of petrolatum does not retard
cleaning; it is therefore beneficial and helps in the buffing operations
as the life of buffs will be longer and the saving in tripoli is quite
considerable and the tripoli will also cut faster.
Hot alkaline cleaners
are most always operated with an electric current, particularly in
automatic machines where the improved cleaning thereby
attained is most essential in the absence of brushing and swabbing.
The work should always be made the cathode as this causes less passivity
than if it were made the anode. Due to the fact that under certain
conditions
metals or colloids in the cleaner may be deposited upon the work a
short reverse electric cleaning action is introduced to assist in removing
this- film or stain. This must be done in a separate solution or it
will
be redeposited as a metal film while the direct current is being applied.
How
many of us realized the importance of temperature control in electric
cleaning solutions, and yet a fused cleaner made up of the aforesaid
composition should be operated at 200 degrees Fahrenheit, in order
to give uniform cleaning action and long life. We all know that the alkalinity
of any cleaning solution is less active at 150 degrees Fahrenheit than
it would be at 200 degrees Fahrenheit. Then if the cleaner in which
the
parts are to be cleaned is made the anode the temperature of this solution
should be kept at 150 degrees Fahrenheit.
Usually in this type of cleaner
only soda ash is used, and as soda ash contains a certain amount of
iron oxide if an excess amount of heat is
used in the soda ash cleaner, the iron oxide will be kept too much
in suspension and therefore will settle on parts to be cleaned and a
rough
nickel deposit will be the result. One other item of importance that
has to be considered is that if too high a temperature is used in this
type of cleaner the action of the cleaner will be too rapid and will
roughen the metallic surface.
Let us consider the water rinses and dips
that should be used before entering the cleaned brass metal parts in
the nickel solution:
1—Cleaner direct current
2—Cleaner reverse current
3—Water rinse
4—Cyanide dip
5—Water
rinse
6—Acid dip 20 per cent hydrofluoric acid
7—Water rinse
8—Nickel solution
If steel or brass soldered parts are to be cleaned the
following method should be followed:
1—Cleaner
direct current
2—Cleaner reverse current
3—Water rinse
4—Cyanide dip
5—Water rinse
6—Acid dip
7—Water rinse
8—Copper strike
9—Water rinse
10—Acid
dip
11—Water rinse
12—Nickel solution
In preparing zinc die
castings for nickel and chromium plating one must be sure to get a
casting that will finish to a very good non-porous surface
as it is almost impossible to chromium plate zinc die castings that
have a rough surface or one that is full of pin holes.
Method of cleaning for
die castings:
1—Cleaner direct current
2—Water rinse
3—Acid dip 20
per cent hydrofluoric acid
4— Nickel solution direct without water rinse
Each
and every one of the different metals has its own problem and must
be studied as such. Cleaning nickel before chromium plating the following
method should be followed in order to do perfect cleaning on nickel
plated
parts:
1—Electric cleaner made up of 4 oz. cyanide, 2 oz. caustic
soda, temperature 200 degrees Fahrenheit—cleaning time 30 seconds
2—Water rinse
3—Electric cleaner—any cleaner that does not contain any
soaps will do—temperature 150 degrees Fahrenheit
4—Acid dip hydrochloric acid 8 Beaume on hydrometer
5—Water
rinse
6—
Cyanide dip—14 Beaume on the hydrometer
7—Water spray
8—Chromium
bath
(Show slides at this point and explain details.)
Slides on chromium—
No. 1—
No. 2—
No. 3—
No. 4—
CHROMIUM
TANK NO. 1 |
Date |
Content
of H2SO4 |
Density
of CrO3 |
Oz.
per gal. CrO3 |
Ratio
of CrO3 to H2SO4 |
Sept. 14 |
.30 |
24.17 |
38.06 |
126 |
Sept. 21 |
.32 |
23.15 |
36.04 |
112 |
Sept. 29 |
.31 |
23.15 |
36.04 |
116 |
Nov. 6 |
.33 |
23.15 |
36.04 |
109 |
Nov. 13 |
.30 |
23.15 |
36.04 |
126 |
Nov. 20 |
.28 |
23.15 |
36.04 |
128 |
Nov. 27 |
.34 |
26.15 |
42.03 |
123 |
Dec. 4 |
.24 |
23.15 |
36.04 |
150 |
Tank
No. 1 would give a very good chromium deposit from ratio 112 to
130, above. 130 it would plate cloudy and rough, below 110 it has
no throwing power. |
CHROMIUM
TANK NO. 2 |
Date |
Content
of H2SO4 |
Density
of CrO3 |
Oz.
per gal. CrO3 |
Ratio
of CrO3 to H2SO4 |
Sept. 14 |
.24 |
23.15 |
36.4 |
150 |
Sept. 21 |
.32 |
23.15 |
36.4 |
113 |
Sept. 29 |
.31 |
23.15 |
36.4 |
117 |
Nov. 6 |
.33 |
24.17 |
38.6 |
116 |
Nov. 13 |
.34 |
26.15 |
42.3 |
124 |
Nov. 20 |
.32 |
26.15 |
42.3 |
132 |
Nov. 27 |
.42 |
25.17 |
40.3 |
95 |
Dec. 4 |
.32 |
25.17 |
40.3 |
125 |
Head
Lamp Bodies. |
CHROMIUM
TANK NO. 3 |
Date |
Content
of H2SO4 |
Density
of CrO3 |
Oz.
per gal. CrO3 |
Ratio
of CrO3 to H2SO4 |
Sept. 14 |
.30 |
22.12 |
34.4 |
113 |
Sept. 21 |
.32 |
22.12 |
34.4 |
107 |
Sept. 29 |
.29 |
22.12 |
34.4 |
118 |
Nov. 6 |
.26 |
24.17 |
38.6 |
147 |
Nov. 13 |
.31 |
24.17 |
38.6 |
124 |
Nov. 20 |
.30 |
22.12 |
34.4 |
114 |
Nov. 27 |
.30 |
22.12 |
34.4 |
114 |
Dec. 4 |
.30 |
22.12 |
34.4 |
114 |
Small
Side Lamps. |
CHROMIUM
TANK NO. 4 |
Date |
Content
of H2SO4 |
Density
of CrO3 |
Oz.
per gal. CrO3 |
Ratio
of CrO3 to H2SO4 |
Sept. 14 |
.41 |
24.17 |
38.6 |
94 |
Sept. 21 |
.40 |
23.15 |
36.4 |
91 |
Sept. 29 |
.47 |
23.15 |
36.4 |
77 |
Nov. 6 |
.46 |
25.17 |
40.3 |
87 |
Nov. 13 |
.62 |
27.11 |
44.2 |
71 |
Nov. 20 |
.52 |
25.17 |
40.3 |
77 |
Nov. 27 |
.52 |
25.17 |
40.3 |
77 |
Dec. 4 |
.47 |
23.15 |
36.4 |
77 |
H2SO4 is
kept very high as we plate parts in this solution that we can
not clean.
12 volts
are used for this solution. |
The
reason for going through this cycle of-cleaning and dip methods by
us can be explained in the following way. Some of you
might remember
the paper read by Dr. Graham at the Detroit convention, entitled “Industrial
Cleaning of Metals.” In his paper he tells of a bonding solution
and he states that he believes it necessary to bright dip or etch metals
for good adherent deposits. I disagree with Dr. Graham and feel that
he either has not had practical experience or has not given this matter
of bonding enough thought to be able to give a good reason for his statement.
Bright
dips, cyanide dips, or acid dips are only used for removing scale, dirt,
grease, and oxides which are formed through either the manufacturing
of the metals or in the cleaning process, and if it were not for this
scale and oxide that has to be removed after the cleaning operations
are done it would not be necessary to use an acid dip in order to get
a good adherent deposit. Then is it not reasonable to believe that if
you can clean metal parts without tarnish and you can neutralize the
cleaning solution in water well enough before entering the nickel solution,
the cyanide and acid dip could be eliminated entirely. So let us go hack
a minute to the cycle of nickel cleaning before chromium plating. One
will probably ask, “Why all the cleaning and all the dips?” We’ll
get to the point at once and explain. In cleaning brass parts nickel
plated for chromium plating the first cleaner mentioned which consists
of caustic soda and cyanide actually does the cleaning, but the film
and the oxide left on the nickel surface from this cleaner can not be
removed with acid and cyanide dips. For this reason the second cleaner
must be used to remove this hydrogen film. Then the acid dip is used
to remove the oxide. The acid dip is followed by the cyanide dip to neutralize
the acid and water to rinse the cyanide.
As cyanide has no effect on a
chromium solution if only a small amount of the same is carried into
the chromium solution, no further rinses
are necessary. See next page before going ahead.
The first two
slides that I will show here represent two solutions newly made up,
and these
solutions are made up according to Mr. Loevering’s
(magic fluid?).
The first slide, as you will notice, shows you that in
this solution we have mond nickel anodes of the nickel oxide type.
Slide
No. 1—
Here let me again offer some criticism or suggestion if you would rather
have it that way. And in doing so, let me quote Mr. Hogaboom’s
own words:
“Mr. Reinhardt
spoke of Dr. Evans’ work. Personally, I think that
every plater in this room ought to read Dr. Evans’ paper. I think
it is one of the most interesting papers that I have had the pleasure
of reading in a long time, and to my mind it explained some of the difficulties
that have been experienced with cold rolled steel. You, that have plated
cold rolled steel, know that you have had some that would plate beautifully.
Others, cleaned and handled in identically the same way, would blister
or peel. That is mostly true on highly burnished steel. You have pickled
it and found a deposit that you could rub your finger on and called it
carbon, stating as I have myself, that they probably put oil on it in
the rolling, and then when they came to anneal it that oil is carbonized
and therefore that carbonized surface was what caused the trouble. It
is my opinion, which must be substantiated by data, that in the rolling
of highly burnished stock they use less lubrication, and there is greater
friction, due to trying to get the very dense structure and the highly
burnished top. That friction causes oxidation. I have taken Dr. Evans’ one
twentieth molar nitrate of copper and put it on a little burnished stock
and it has taken two hours before I would get a precipitation of copper,
and during those two hours adding a glass rod of fresh solution directly
upon the spot. If I were to electrolytic pickle that, and, as Dr. Graham
said last night, put hydrogen on so as to reduce that oxide, use cathodic
pickling, I could immediately get a copper spot. Collecting a number
of samples of cold rolled steel, I got everything from -an immediate
precipitation of the copper to two hours, according to the stock. So
it is my opinion that Dr. Evans has explained a difficulty that has been
experienced by platers with rolled steel and it is not a carbonized surface,
but an oxidized surface, caused by the friction or the heat of the friction,
due to rolling.”
Right here we cannot help but see that the film
on the steel which Mr. Hogaboom could not dissolve with either acid
or cyanide was nothing else
but a carbonized or hydrogen film. But as he states himself with an
electrolytic pickle he could remove this film of which he speaks.
Mr. Hogaboom
accomplished two things with his electrolytic pickle—the
hydrogen gas evolved removed the carbon or hydrogen film and the acid
action removed the oxide. On the other hand he could have accomplished
the same results without using the electrolytic pickle by going through
a cleaning cycle of the same kind as mentioned in the nickel cleaning
for chrome plating. So you can easily see that most of our trouble is
always with us as most of the platers will not go into details and pay
enough attention to facts as he goes along to be able to overcome some
of his troubles.
You may notice on Slide No. 1, where we were using the
nickel oxide type anode, that we started our solution with a pH of
5.4 and maintained the
solution at that pH for thirteen days. The metallic concentration remained
the same. The pH changed slightly. Once the pH changed to 5.6. Then
after adding two gallons of hydrofluoric acid the pH changed to 5.3 and
5.4.
Sodium perporate was added almost daily. The nickel chloride was maintained
at 32 ounces per gallon, which dropped to three ounces per gallon.
The nickel deposit was rough and sometimes it was almost impossible to
buff
the nickel. About the twelfth day we were instructed to chromium plate
all parts, and we found at once that the nickel was too hard and that
it would invariably peel off the minute we tried to chromium plate
the same. Up to this point we did not check for boric acid.
It became evident
at once that we had to change our pH in this solution. So we added
four pounds of sodium carbonate and eight pounds of sodium
perporate and then, by adding perporate every day, we finally brought
our pH up to 5.8. At this point it was noticed that the metal concentration
dropped one-half ounce per gallon. We then added 800 pounds of single
nickel salt, which brought our metal concentration to 6 1/2 ounces
per gallon. Our nickel chloride by this time went down to 2 3/8 ounces
per
gallon and the boric acid to three ounces per gallon. After examining
our nickel anodes, we found that they were black and sponge-like. We
decided not to add any nickel chloride at this time. We removed the
anodes and cleaned them thoroughly, and then made bags from cheese cloth
and
put the anodes in the bags, figuring that we would be able to overcome
the rough nickel deposit. As we had decided the nickel anodes were
to blame for our trouble, the anodes by this time were a terrible looking
sight.
We got in touch with the maker
of the anodes. After their metallurgist saw the anodes he gave instructions
to return the anodes. These anodes
were replaced with another type with a higher nickel oxide content. While
these anodes were much better than the first ones they were still rough
and oxide would form on the anode which required cleaning from time to
tine; and the nickel deposit would be just as rough as before. I might
state here that we were using 30 amperes per square foot and the solution
was operated at 120 degrees Fahrenheit. The maker of the anodes now figured
that the high amperage caused some of the trouble. Filtering the nickel
solution only made matters worse, so we finally decided that some of
the trouble must be with us. I began to investigate cleaners, acid and
cyanide dips. You can well imagine that the cleaning salesmen began to
have some fun. We knew we had no reason to blame them, but we were out
to find the cause of our trouble and we blamed everybody we could think
of—even the composition manufacturers got into this.
About this time Mr. Gilchrist, who at that time was with the Ternstad
Manufacturing Company, one of the General Motors Divisions, decided that
he could not use 99 nickel anode and went back to 95 and 97. I decided
that I would not go back to that, so I kept on investigating and fighting
every day to overcome rough nickel.
(Show Slide No. 2.)
Slide No. 2 shows the same solution with the depolarized anode oxide
sulphuric type. The anode corrosion in this solution was more uniform
as far as the upkeep of the metal content of the solution was concerned.
Otherwise the anode was rough and did not corrode with a fine grain.
The nickel deposit was just as bad as in the other solution. In general
conditions prevailed just the same as in the first solution with the
nickel oxide type anode. You must remember that hydrofluric acid was
used in both of these solutions. This solution plated very rough.
George
B. Hogaboom found that the same condition existed in his experiments,
and an investigation of nickel solution Slide No. 1 and Slide No. 2 would
in itself explain that what George B. Hogaboom found out about anode
and cathode efficiency was true. (Anode efficiency—99.8; cathode
efficiency—79.8.)
There is one item that Mr. Hogaboom overlooked.
This item is: if the nickel deposit could be kept finely grained and
free from rough nickel,
with a slight modification one could get to the point of a self-sustaining
nickel solution which in itself would be an ideal condition. So far
I have not discovered how to overcome this condition and at the same
time
have a fine nickel deposit.
Slide No. 3.
This solution was made up without hydrofluric acid. For a period of
over a month, we added 3500 pounds of single nickel salt to keep
the metal
content uniform, also allowing drag-out of the solution. Two thousand
pounds of nickel chloride were added to keep the metal content and
the chloride content uniforrn. Our nickel chloride content was kept
around
five ounces per gallon. The pH of the nickel solution No. 3 was kept
constant or nearly so by the addition of hydrochloric acid-and sodium
perporate. We kept daily check on our solutions. Boric acid was kept
at four ounces per gallon. It required 1300 pounds of boric acid per
month to keep the boric acid at four ounces per gallon. We added 250
c.c. of hydrofluric acid during the month. The plating in this solution
was much better than before, but we could not get away from rough nickel.
Although the rough nickel was not as bad as in the other solutions,
we still had it with us and it caused a lot of trouble in nickel
buffing.
Slide No. 4.
In Slide No. 4 you may notice that we more than doubled or nickel chloride
content or in other words we brought it up to 11 ounces per gallon.
As we started our solution with more nickel chloride, our metallic
nickel
content was only 52 ounces and the pH at that time was 5.9. It required
3000 pounds of single nickel salt per month and 2000 pounds of nickel
chloride to keep the metal content and the nickel chloride content
constant. We had very little trouble controlling pH The pH was kept
constant by
two pints of hydrochloric acid and a slight variation of sodium perporate
from 4 to 6 pounds per day. We were able to hold the 4 ounces of boric
acid by the addition of 2000 pounds of boric acid during the month.
In addition to the boric acid we added 250 c.c. of hydrofluric acid
daily
to control the rough nickel deposit.
The nickel deposit from this solution was the lest that we were ever
able to obtain from any nickel solution we tried. The nickel coating
was very easy to buff and would never peel under any condition.
When one
considers that we plated 3960 head lamps in nine hours with an average
of three square feet to the lamp, figuring two square feet
for the outside surface and allowing fifty per cent for the surface not
directly exposed to the anode, and other parts such as side lamps, side
lamp doors and head lamp doors—altogether about 21.284 square feet
and 7128 square feet of reflector; the amount of nickel salt, nickel
chloride and boric acid added during the month were actually carried
out in the drag out. I feel that this type of solution shown in Slide
4 is as near perfect as one can get for general production work.
Show
slides from 4 to 24 nickel anodes, 24 to 26 porous nickel deposit.
While the hour is getting
late, and we have very little time left to go into further details
about the plating situation, I do wish to make
a few remarks about pitting. When we talk about pitting we get on dangerous
ground at once. We all seem to know so much about pitting that on the
face of everything that has been said and written by authors we really
ought not to have any more trouble with it. Here are some of the causes
of trouble given by certain writers: too high in acid, too low in acid,
high current, dilute solution, undissolved air, oxygen organic matter
and what not. If we know the real reason for pitting why haven’t
we eliminated all this trouble? Supposing we have to cut a piece of wood
ten inches long to fit in a certain space, we could not very well cut
the piece of wood twenty inches long and expect it to fit in the space
where ten inches is required. So I believe that with solutions under
control and all other conditions under control it is impossible to have
pitting.
I thank you. Slide
5—Cast 90-92 per cent nickel. 75x.
Slide 6—Cast 95-97 per
cent nickel.
Slide 7—Cast 95-97 per
cent nickel.
This illustrates what an anode looks like when there are high impurities.
Slide
8—Cast 95-97 per cent nickel.
If an anode is not scrubbed during its life the carbon and iron will
hold the original shape of the anode. The nickel will be leached out.
Note the core of cast nickel—all outside of the core is carbon
and iron.
Slide 9—There is no
slide.
Slide10—Cast 99 per
cent nickel.
Note the structure especially along the outside edges where the solution
will attack the grain boundaries. This is better illustrated later
on. See slide number 13.
Slide 11—Cast 99 per
cent nickel.
The spots are nickel oxide. The nickel oxide is very high. The highest
it should be is about 1.10 per cent.
Slide 12—Cast 99 per
cent nickel. This shows the intergrain boundaries clearly.
Slide 13—Cast 99 per
cent nickel.
This shows how No. 12 will be attacked in a plating solution. Note
how the intergrain boundaries have been dissolved and some grains of
nickel
are about to leave the anode before being dissolved in the solution.
The anode is disintegrated rather than corroded.
Slide 14—Electrolytic
nickel. Starting sheet at the beginning of the deposit.
Slide 15—Electrolytic
nickel annealed.
Slide16—Electrolytic
nickel rolled.
In No. 15 note the spaces between crystals.
In No. 16 it is shown that the crystals are not held together and the
metal will fall apart. That accounts for the metallics given off by
electrolytic nickel in a plating solution. Contrast this with a rolled
anode. See
No. 18.
Slide17—Cast nickel rolled—99
per cent.
Note that the grains do not hold together. I rolled at least 12 pieces
before I got this one. The slightest increase of pressure during the
rolling would cause this piece to break up into a number of small pieces.
This is characteristic of cast nickel at present.
Cast nickel must be heat treated and forged before it can be rolled.
An ingot 14 inches by 14 inches by 45 inches long is forged with a heavy
drop hammer to 3 inches wide by 2 inches thick before it is rolled for
anodes. For sheets it is rolled into slabs inches wide by 1/ inches thick.
Slide
18—Forged and rolled—99 per cent nickel. This piece
is about .015 inches thick. If he dark lines are just light shadows when
photographed.
Slide19—Rolled 99 per
cent nickel. Picture of the outside edge of the cross section of an
anode.
Slide 20—Same
as No. 19, except the picture is of the center of the anode. Note the
uniformity of the structure throughout the anode.
Slide 21—This
slide shows you a Mond nickel oxide type anode as used in nickel solution
as per slide No. 1 and No. 2
Slide 22—Shows you a
depolarized nickel anode sulphur oxide type anode as used in solution
as per slide No. 1 and
No. 2.
Slide 23—Shows the Mond
nickel anode of somewhat higher oxide than the first anode. This anode
was
used in solution as per slide No. 4 with
11 ounces
of nickel chloride and 4 ounces boric acid.
Slide 24—Shows anode
depolarized of the sulphur oxide type used in solution No. 4 with 11
ounces nickel
chloride.
(Cuts mentioned here will be printed in June issue.)
A. E. S. PAGE
Assembled Expert Scraps With and Without Significance
Don’t
Kick
If some brother is
prospering or getting along a little better than you, let him prosper.
Don’t grunt and grumble; don’t
kick. Say a good word for him; look pleased and let it go at that.
If you see your
Branch is getting along nicely, feel good about it. Help things along.
Shove a little; try to get some of the benefit yourself.
Don’t stand around like a bump on a log and waste your time feeling
sore because some other brother has had the sand to forge ahead and prosper.
Do a little hustling yourself, but don’t kick. If you can say a
good word, say it like a man.
If you are sore and
disposed to say something mean, keep your mouth shut. Don’t kick.
No man ever raised
himself up permanently by kicking someone else down. We are helped
when we
help our brother. Be ready to
give a kind word;
give it liberally; it won’t cost you a cent, and you may want one
yourself some day. You may be rolling in wealth today and raising whiskers
tomorrow because you can’t raise the price of a shave. So don’t
kick. You can’t afford it. There’s nothing in it. Inflated
Northe: “What’s
a high pressure salesman?”
Weste: “A high pressure salesman is one who is full of compressed
wind, and we have met some fellows in our profession just this way.”
Don’t
Quit
When things go wrong, as they sometimes will,
When the road you’re trudging seems all uphill,
When the funds are low and the debts are high
And you want to smile, but you have to sigh,
When care is pressing you down a bit,
Rest if you must, but do not quit.
— Selected
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