Jeweler’s Shop Machines
In this article we lists the types of jeweler’s shop machines needed for jewelry making including suggestions on the good ones to use for your trade..
A reasonable anvil may be made from a piece of railroad track, with quite a bit of work. Short sections may often be had free from workers laying tram or train track or from the railroad yards. I’ve had a class where they raided new tram laying lines and the whole class came back carrying chunks of track cut to size for anvils. I-beam can function as an anvil but has a horrendous ring to it when struck.
Bulldozer teeth make a good anvil, as do surface plates, large mower teeth and assorted other pieces of junk steel. Take to frequenting junk yards and flea markets. The bottom of an older iron makes a good hard surface plate.
A good anvil can cost between 400-600 dollars. The best way to find one is to look in farm auctions, old metal working shops and possibly large stable workshops. Farriers use anvils and blacksmithing equipment and in some areas are more common than blacksmiths. Flea market prices vary from 75.00-140.00 depending where in North America you are buying it.
Like any home-made or adapted electrical tool you must have a licensed electrician look at it before you use it in a home or business. Insurance people don’t like them unless they are approved-not to mention the chance of injuring or killing yourself. Plan in all such things for the worst case such as spilling your coffee across the table and onto the tool and you. A satisfactory buffing machine may be made from a washing machine motor which is obtainable cheaply for two or three dollars or unbolted from a junked machine for free with permission of the owner discarding it.
Remove the pulley and replace it by a tapered arbor which costs about five dollars. The motor is then mounted in a wooden frame or on a large wooden block attached to a sturdy table and an on/off switch is installed in the line. The total cost should be under fifteen dollars. The surface speed of the buff which is low may be improved by using a wheel of large diameter such as an 8″ wheel which because of its larger size has a greater surface speed of revolution than a smaller one for a given speed of rotation.
One may also rig up various arrangements of pulleys and belts to get almost any combination of speeds out of it but the motor and wheel by themselves are perfectly useable. Washing machine motors and similar motors usually have an RPM of 1750 while most commercial polishing machines use an RPM of 3450. This can be adjusted for as described above but it is adequate for general purpose use as is.
One can of course only have one spindle on such a motor. Make sure you get an appropriate tapered arbor (right or left hand) for the direction of rotation of the spindle for the motor you use. Best is to get a tapered arbor from a machinists supply because it has a very wide taper and so can be used with lower priced buffs from the hardware store which usually have a large center hole. Jeweller’s buffs from the jewellery supplier with a smaller hole are more expensive.
For somewhat more expense a double spindled 3450 RPM motor can be bought and used as a polishing motor. At about this price point one might as well buy a proper polishing motor which should ideally be of sealed construction and have self lubricating bearings. Rumor has it that Baldur ® motors are the best for this purpose.
One can also purchase an inexpensive grinding unit made in Asia from companies such as Busy Bee or Harbor Freight Salvage (see supplier list in appendix). Such grinders can usually be bought locally for between 30 and 50 dollars on sale. Check to see that the grinding shields (the metal ends) can be removed and then one can take the grinding wheels off and install the appropriate direction rotating tapered arbors. It should give you a good, sealed construction polishing motor that runs at 3450 RPM for an extremely reasonable price.
A small used dental machine is very cheap, as low as $30.00 or so and is quite reliable for fairly small castings. They are often obtainable inexpensively and I have seen a few over the years that were surplus armed forces models; I’ve even once had a small kiln given to me and struck off a base inventory as being obsolete once it was known there was someone who could use it.
Aside from such a centrifugal machine one may easily use a technique called .i.steam casting;. One burns out the investment in a flask made from a piece of cut off steel pipe or using a tomato paste can or similar tin can. Perfect burnout flasks may be bought as exhaust system components at your local auto supply store or even more cheaply as sections of steel fence posts at the hardware store.
An ordinary hot-plate may be used as a burnout kiln by making a little sheet metal muffle around the burner. In the past even a flower pot has been suggested for such a muffle. A small aluminum plate may be used to catch the wax as it burns out. A jar lid is prepared by laying wet paper or wet cloth in it. The lid is larger than the pipe. One melts the metal in the sprue base in the investment and then with an heat resistant glove jams the lid on over the pipe, holding the wet material down hard against it. The steam generated is sufficient to force the metal into the mold if done correctly. One can set up a beer capping machine to provide good parallel pressure onto the flask top for steam casting. Level, tight pressure is necessary for this procedure to work well.
An excellent cheap alternative that has the advantage of good casting results and a very small space requirement in the shop is vacuum casting. A vacuum casting machine can be made fairly easily using an old fridge compressor or a proper vacuum pump and motor. The same machine serves as a vacuum investing machine for removing bubbles from casting investment before it sets. Vacuum casting is very effective if set up correctly.
There are a number of other inexpensive ways of casting; I refer you to .i.McCreight’;s ‘Practical Casting’ book. .i.Sling casting; works well. This is where a flask holder is made on the end of a chain and handle, the metal is melted in the button area of the flask and then the whole thing is swung around. It sounds rather scary but those who have done it say it works well. Scott .i.Walker ; in Calgary welded a great flask container for this and has successfully cast 90 grams with it with no problems. He also uses a self-cleaning oven as a burnout kiln. It reaches the temperatures required.
If you need a drill press for production runs which can’t easily be handled by your flexible shaft there is a rather nice stand for an ordinary electric drill available, or one can buy one of several miniature drill presses for jewellers. There are quite good ones built for a flexible shaft handpiece. Unimat has an accessory for making a small drill press. One can also buy kits in unfinished form for it (Casting Specialties), or construct one from pulleys, shaft, motor and chuck. It’s probably cheaper to buy one, at least in terms of time. At many machine tool suppliers such as Harbor Freight, Busy Bee and Industrial Pipe and Steel (check source pages) tools like drill presses can be had relatively cheaply. Drill press vises are inexpensive.
A rough and ready trick used by stonesetters is to tie a bungee cord to the ceiling over the bench pin and knot the end of it just behind the handpiece of the flex shaft. The handpiece then floats in the air just off the bench surface and can be reached for and used quickly and easily. Most important however is that this gives one a vertical resistance to any downwards pressure on the tool-so it is rather like having a drill press; everything is kept more or less vertical. For setting it also gives one more sensitive control of a burr held into a setting.
An aid for holding small parts for drilling is to smear a little sealing wax or pitch on a board, warm the parts and drop them in the wax to allow them to be easily drilled. Dopping wax can also be used.
This is a really essential piece of equipment. If you can’t buy one for some reason there are several alternatives available. One can buy an attachment for an ordinary power drill, grinding wheel or other motor. One can control the speed using a rheostat appropriate for the motor size (light dimmers are not intended for motors). Kirby ® vacuum cleaners even have a flexible shaft attachment similar to the ones for motors. One can use a Dremel ® tool which is similar to a flexible shaft but without as much torque and with the motor in the handle. In general Dremel ® tools while somewhat less expensive than a proper Foredom ® type one do not measure up in powerful or production applications.
There are also now miniature versions of the Dremel ® such as the Mini Mite ® which are small enough to be comfortable in use and run with a battery pack that takes about three hours to recharge. Running time on a charge is about 1-2 hours. One can obtain this tool for less than 30.00 in the US and about 15 for an extra battery pack. The tools are chucked in with collets so that one might want to buy a range of collets for it. The collet that comes with the tool fits a range of bits including all standard burrs. One can make a reverse collet out of a piece of tubing with slits in it which is slid over the smaller tool and held in place by the collet on the tool. This enables one to inset various sized bits using a single collet. This is my favorite tool for carving steel stamps with.
If you are planning on getting a Unimat lathe there is a flexible shaft attachment available for it. It is also possible to buy just the Foredom ® handpiece, cable and sheath and attach it to some kind of controlled speed motor. Die grinders or other motors attached to a sewing machine foot pedal work well.
I’ve heard of people using graphic designers electric erasers or pet toe-nail buffing tools as replacements for flex shaft like tools.
I’ve heard of someone using an industrial blender mounted sideways on the wall of their shop with the flex shaft drive cable hooked up to the drive shaft in the center of the blender. Different buttons translated into various speeds.
Kevin and Kay Plunkett have several die grinder motors hooked up to standard flex shaft cables and foot pedal speed control switches. These run at 28,000 RPM versus the standard flex shaft at 14,000 RPM and were much cheaper than a standard flex shaft motor. They ran for years without trouble.
I refer you to Lee Marshall’s Bonny Doon Press company for the best and most complete tooling system around, for home built versions see Susan .i.Kingsley;’s excellent 1993 work on Hydraulic Press use and The Metalsmith Papers (from SNAG). Harbor Freight Salvage has the cheapest complete one (this is the one I’ve got-needs a little mucking around and re-arranging to work but does me fine) or contact Barbara J. McCartin (see sources) for a superb 20 ton press, welded, with retracting springs for 200.00 plus shipping. As she is in New Hampshire the closer you are to her the better a deal this is.
R.T. blanking or what are now being called ‘pancake’ dies are a fantastic and easy production method for blanking out shapes of metal. You can order the original paper by Robert Taylor from Goldsmiths Hall in England or see various descriptions such as in Kingsley and Wicks. A press may be used or some other parallel surfaces moving together under pressure. Sheltech ® makes hardened tool steel dies for R.T. blanking at very reasonable costs. Check the sources for their address.
A covered crock pot works very well. One must take care not to splash the acid around and to keep the outsides clean as they tend to corrode if not cared for. A pickle solution may last for months if used with care, replenished with water when necessary, kept clean and so on. I suggest caulking all seams of the crock pot with silicone, caulking the heat control fixed on low (for a shared shop) and regular wiping down.
For larger work it is possible to use a plastic basin with a cover made for it. This may be placed on a thick bed of sand in a metal tray which is on the burners. Use a very low heat or use the pickle cold, as it is quite possible to have a melt down of the plastic. Better is a food-grade polyethylene drum such as is found discarded outside restaurants and food services. A five percent Sulfuric acid solution works well and may last longer than Sparex ®. Remember the reason jewellers switched to Sparex ® is safety – you don’t have to work with dangerous acids or store them.
Sparex ® is almost the same as sodium bisulfate which is commonly sold as ‘swimming pool acid’ and is used to change the pH of swimming pools and hot tubs. It can be unnerving to be in a hot tub and have the attendant testing it and then ladling ‘sparex’ into the tub. It is far less expensive there than at the jewellery suppliers. Hardware, garden and pool suppliers usually carry swimming pool acid. An even larger user is the cleaning industry and great drums of the material are apparently used by industrial cleaners for cleaning toilets.
In a pinch vinegar and salt make a very good safe home pickle, about one cup vinegar to one teaspoon salt or more.
An old fashioned pickle is a fairly dilute solution of alum which apparently has relatively few fumes and also does not plate copper on one’s work if iron is introduced to the pickle (hearsay).
An alum solution is also used for dissolving out broken drill bits from jewellery pieces. One simmers a concentrated solution of alum and a broken drill bit embedded in a piece dissolves out in about twenty minutes.
An emergency pickle is to sprinkle salt on a cut lemon and rub it over the metal to be pickled.
For .i.pickling long and tall objects; use a long and tall container such as a bottle to pickle in.
If you ever get .i.copper flashing; on your metal from steel contamination in the pickle or when working with brass it may be quickly stripped by taking a scoop full of pickle from the pickle pot and mixing it with an equal amount of hydrogen peroxide from the drug store. This strips off copper flashing in less than two minutes. It may be returned to the pickle pot after use as the peroxide breaks down to make water. The mixed solution is good for about fifteen minutes unless it is sealed into a dark bottle in which case it can be re-used.
If you need one you need one. For some thick things you can do it the old fashioned way, that is to hammer the ingot into useable sheet. For the thicker gauges it is possible to do reasonably quickly. One can get quite good at it with practice but it is definitely not a time-saving procedure though I have a friend who did it for years. He now has a mill.
If you have a contact in Poland Polish rolling mills of very good quality could be had until relatively recently quite cheaply with small cost for shipping. The prices were remarkably good, less than 200.00 for a double sheet and wire rolling mill about 6″ wide. I have heard however that prices have since been adjusted to match western (British – Durston, Italian – Cavellin) mill prices. Another source is Bombay India where quality varies but local prices are good. Contacts are necessary in both places. Otherwise hunt locally for one no longer valued in someone’s garage or attic, some older jewellery store that used to have a repair or manufacturing shop or a defunct high school or military jewellery program. Come to think of it maybe college programs too.
This is very useful for any kind of production and for polishing small items and chain. Use mostly smooth steel shapes, not sharp ones. A goldsmith friend of mine from Toronto, Jeff .i.Demand;, tells me that as foreman of a factory he used ten thousand stainless steel earring posts as the finishing polishing tumble. He went so far as to cut up a lot of stainless wire into short bits to make his own version of this tumbling media.
An ordinary rock tumbler works fine except if it is made of vulcanized rubber. This turns your silver black or grey and the tarnish is very hard to remove. The drum should be plastic or wood, something that won’t react with the silver and should have facets or ridges on the inside to ensure proper tumbling; a falling of the media rather than sliding about the insides of a smooth drum.
If you have a round drum a piece of Plexiglass can be heated, bent into a faceted hexagonal shape which fits into the drum. A thick oil soap made from a vegetable base like Murphy’s Oil Soap works very well as a lubricant. A teaspoon of ammonia may help to cut grease if you are combining steps. I have seen several home built rotary tumblers. They need to rotate relatively slowly so either a slow rotating motor or a system of pulleys is used to achieve a slower speed. We’ve suggested people make their container by attaching a Tupperware® or similar container to the plywood surface that is attached to the angled motor and rotates slowly. Then one can change containers simply be changing nesting ones in the attached one.
Note that because the requirements of a tumbling polishing media are that it be smooth and hard it doesn’t have to be steel: bags of tumble polished agate chips from a rock shop should work well.
A vibratory tumbler can be made inexpensively. Look at heavy duty vibratory tumblers to find out how to construct a home version. Vibratory tumblers are used for deburring operations which take the place of abrasive work like sanding. Rio Grande among other suppliers sells deburring tumbling media.
As always look for someone who uses more of a tool or material than jewellers do. The cheapest source for a vibratory tumbler for a long time was gun shops. Gunners tumble their brass shells to clean and polish them before reloading them and there are apparently a lot more gunners around than jewellers.
Rubber Mold Vulcanizer
This is basically a commercial heavy aluminum rubber mold frame, two steel plates and two C-clamps. The frame can be laboriously sawn out of thick aluminum sheet, be cast, be a cut-off a thick rectangular pipe or purchased.The model and rubber are laid in as usual, and then the steel plates are clamped as tightly as possible to the frame with the C-clamps and the whole assembly is placed in the oven at 350-400o F for an hour. Preheat the oven. Check instructions. It is a good idea to tighten the clamp periodically if you have used excess rubber. Jeff Demand uses a small toaster oven for his vulcanizing heat source with clamps for the frame. These days too one can use other molding compounds, for short runs the alginate systems and for permanent ones compounds such as the Silastic ® ones.
Vacuum Casting and Vacuum Investing Machine
This may be constructed from an old refrigerator compressor with the intake hooked up to a rubber table and Plexiglass bell. I’ve also seen the vacuum unit from a milking machine used very successfully as a vacuum casting unit. The refrigerator unit would work for that also
A shop vacuum cleaner may be bought relatively cheaply or even found discarded and may double as a dust collector if hooked up to a hood around the polishing motor. For a more professional dust collection system one might consider looking in a woodworking tool catalog for a small to medium size .i.dust collection; system. A vacuum cleaner can be loud and for less than 300.00 one can get a top quality system-sounds expensive but not too bad for a professional system.
I have seen severalwax injectors made from a electric pressure cooker, fitted with gauges and the Jelrus replacement injection nipple. A fridge compressor can serve as a compressor to run a wax injector with a gasoline filter in the line to filter the air going in to it. Jeff .i. Demand; has constructed a small wax injector intended for file-a wax type waxes which operates at higher pressures (30-40 psi) and enables him to inject his molds with wax which can then be filed and further worked.
There is an orange injection wax available for regular injectors which is soft and flexible, has good memory during removal from the rubber mold but hardens after three days into a material that can be filed without gumming and clogging the files. Rio Grande is the source I’ve heard quoted.