Hi all,

Does anyone have any tips for attatching a coin to some sort of spindle that can then be put in a drill chuck for cleaning, softening, smoothing etc.

I did a short jewellry making course years ago and we made a up a thing called a Dado? stick for holding the stone fixed on the end of a bar for grinding, polishing etc.... I can't remember what material was used for the fixing.

I have some large dollar size commemerative coins that I intend to grind almost smooth then get nickle OR chrome plated for doing three fly type effects.

Regards Alan

Since the coin wll probably get hot while cleaning/grinding whatever, I would consider not actually glueing the coin at all.

Try this, though I can't guarantee it. Get an old valve stem from a car engine and fit it in an electric drill or overhead drill. Coat the face of the valve with rubber glue or glue a sheet of thick rubber to the valve face. This will be the surface which will contact against the coin.

Then get a sheet of wood or cork and coat it with rouge/toothpaste or other polishing paste and lay the coin face down on the paste and drive it with the valve stem from above,at low speed if possible.

To really grind off the face of the coin, lay the coin face down on a flat wide metalworking file which is firmly held down with clamps to the drill bed and rotate the coin as slowly as possible.

I would try this with common coins first before trying it on the actual commemorative coins.
Regards
RangeCowboy

If you have a router, you can grind a shallow (as in thinner than the coin you are working with) round coin-sized indentation into a piece of wood to set the coin in. You can then use anything from orbital sanders to polishing tools to accomplish your task. Avoid belt sanders because if the coin comes loose, it becomes a projectile, not a desired effect.

A different approach...

Cut a 1/2" thick wood square with sides a little under twice the diameter of the coin. It the center of the square, drill out a hole the size of the coin with a hole saw bit or plug bit. Keep the plug. Split the square down the middle. Very lightly secure the square in a table clamp. Put the plug inside the hole, holding it inside with a finger from underneath. Place the coin on the plug, and lower to a height with the surface of the coin just flush with the top of the wood square. Tighten down clamp, securing the coin. With a hand drill or better yet a drill press, grind the face of the assembly (both the wood and the coin) with a sanding bit.

I like Rob's idea. I would recommend using a drill press and spade bit (or forester bit) to make the hole if you could find one the proper size. Then use the drill press for the grinding.

Thanks a lot guys, some great ideas there that I will put into practise this week.

Regards and thanks again

Alan

Alan,

Lapidary shops have that cement you were looking for to work rocks into jewelry.

It's a two part mix that is impervious to heat. When finished, put it in your freezer and the coin will pop off by itself or can be removed with a quick flick.

Best,
Ray