Historical Articles

August, 1952 issue of Plating

 

Barrel Finishing
III. Planning a Barrel Finishing Department

(Part I, Some Fundamentals, was published in the December, 1951 issue and Part II, Selection of Equipment, in the March, 1952 issue.)

Morris S. Shipley
President, Industrial Supplies & Equipment Company, Greenwich, Conn.

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INTRODUCTION
The following discussion covers the essential points which should be considered in the physical set up of a barrel finishing department, exclusive of the equipment itself, which has been dealt with in Part II of this series.

Most of the items are applicable to all such departments, but some are not essential for small installations. Before deciding against any one, however, it should at least, be given consideration.

MONORAIL HOIST
An electric hoist is almost an essential for any department. It should be of the bridge crane type and should be so constructed that it will serve not only all barrels but every other unit of the department—chip bins, incoming work, outgoing work, etc.

WATER SUPPLY
Water should be piped directly to each barrel. The final connection can be either through a short piece of hose or through swiveled pipes which will discharge directly into the barrel.

If it is possible to arrange without too much expense, hot water should be available as well as cold. Soaps and compounds dissolve so much faster in hot water that cycles can often be shortened by its use.

COMPRESSED AIR
A compressed-air line, with a hose connection for each barrel, is a great time saver. It is used to blow the fine pieces of abrasive off the gasket which seals the doors just before these are clamped shut. These fine particles, if not removed, tend to spoil the door seal and eventually destroy the gasket, causing bad leaks.

Fig. -1. Artists’ view of well planned tumbling department. 1. 60-2 Machine; 2. 48-2 Machine; 3. 32-2 Machine; 4. X-242 Machine; 5. Manual Separating Table; 6. Hoist Pan; 7. Chip Bin (single); 8. Chip Bin (double); 9. Water Tank (rinsing); 10. Oil Tank (rust prevention); l 1. Weighing Scales; 12. Compounds; 13. 2000 lb Capacity Hoist (electric or air); 14. Bridge Crane; 15. Bridge Crane Hoist Bearn;16. Traverse Rails for Bridge Crane; 17. R. F. Screen for Separation; 18. Drain; 19. Hopper

DRAINAGE AND PITCH OF FLOOR
Modern wet-rolling techniques involve the use of large quantities of water which must be disposed of as speedily as possible. As some kind of soap or burnishing compound is almost always present and tends to make floors slippery, arrangements should be made to keep the water away from where the workmen walk, to the greatest possible extent.

For this reason, barrel-rolling departments now have the drains at the back of the barrels rather than in front. The floor is pitched from front to back. A pitch of 1/8 inch per foot is the minimum, but a pitch of 1/4 inch per foot is far better.

The drain itself can be a concrete or brick trough, a foot or two back of the barrels. It should be about a foot wide and 6 inches deep.

The actual drain opening should be in the nature of a sump, with the open end of the drain pipe raised an inch or two above the bottom. This, in turn, should be divided from the rest of the trough by baffles about 2 inches high. These baffles prevent clogging of the drain pipes and permit sludge and other heavy foreign matter to settle where they can be removed periodically.

MATERIAL STORAGE
Burnishing compounds and cleaners are ruined if they get wet; or even damp. As they sometimes are quite expensive, care should be taken to provide dry storage space for them.

A raised platform which will keep them off the floor, placed as far as possible from the tumbling barrels, is easy to provide and entirely adequate.

PARTS STORAGE AND HANDLING
Many an otherwise well-planned department is badly hampered because both unfinished and finished work clogs the working space and slows operations

In laying out the department, ample space should be provided for storage of both unfinished and finished work—out of the way of workmen. Furthermore, bottlenecks should be avoided. Aisles and doorways should be wide enough to permit easy movement of parts and supplies, in and out.

Fig. 2. Plot plan of tumbling department

PERSONNEL
Barrel finishing has graduated from being a hit-or-miss process, but all too often management still thinks of it as merely a strong-back job. Actually, the man in charge of a modern barrel-finishing department, whether it be one barrel or one hundred, has just as much responsibility as the foreman of the machine shop or the plating department. He must be intelligent and have an inquiring mind so that he will profit by his own experience and that of others, and he must have an interest in the development of sound techniques for the work at hand.

It is obvious, therefore, that the selection of the proper man for the job is just as important as the selection of the proper equipment.

The amount of labor required varies from plant to plant. To a large extent it depends on variety of work involved and length of runs. Normally, the longer the run, the more barrels one man can handle.

As a general average, one man can take care of four barrels. If the cycles are short and media must be changed often for different types and sizes of parts, one man may be needed for every three barrels. Conversely, if runs are long and only a few different parts are involved, one man may be able to handle five, six, or more barrels.

Fig. 3. Cross section of department showing pitch of floor, location of drain, and the height of bridge crane.

CONCLUSION
This article, actually, is a check list of things to be thought of in laying out the sort of department that will pay dividends. None of them should be overly expensive and none are difficult.

Whereas many of the points may have seemed rudimentary, it is hoped that this outline will help newcomers to the field to plan properly from the start and so avoid costly revamping at a later date.