How to make gold wire and sheet for inlay
I purchase 24k gold for inlays from http://www.hooverandstrong.com/ If you have a gold roll and draw plates, the least expensive way to purchase gold is as "casting grain". Melt the casting grain into to a clump, roll it for sheet and pull it through drawplates for wire.
It depends on what size inlays you are doing, but .013" and .017" diameter wire seems to be all around handy for the size projects I do, and for sheet, generally .020" thick.
www.gesswein.com is a source for a gold roll and draw plates. When shopping for a gold roll, be sure to find one that can roll flat along with round (or square wire). The procedure for producing sheet and wire is:
1. Melt the 24k gold casting grain or scrap 24k in a crucible . A propane torch will work with smaller amounts of gold. NOTE: Be sure to coat the crucible with boric acid first (you only need to do this once with a new crucible).
2. After the gold is melted into a clump, remove the flame slowly so it doesn't cool too quickly. (it will sink in the center of the gold clump if it cools too quickly). When it is still cherry red, take a pair of pliers and pull the gold out of the crucible so it doesn't stick to the bottom of the crucible. If you do get a stuck chunk of gold, just heat it back up and pull it out sooner with the pliers. After the gold is cool, clean any boric acid off the clump, and be sure the surface looks pretty clean. If there is foreign matter in the surface, file or air drill (NSK rotary tool) it out. You want the gold to be clean before rolling it.
3. Begin rolling the clump into a sheet with the gold roll. You may need to anneal the gold now and then (maybe every 4th or 5th rolling). Anneal it by heating it until it is slightly red and let it cool slowly.
4. When the gold sheet is about 1/8" to 1/16" thick take a pair of sheet metal cutters and cut some strips off around the edge of the sheet. (this will become the wire). Continue rolling the sheet to the thickness desired.
5. Take the strips of gold you cut off, and begin rolling them through the square or round wire indentations in the gold roll. Take the square or round wire down as small as the gold roll will let you.
6. Now take this wire and begin pulling it through a draw plate. Again, you will need to anneal the wire now and then by heating until it is red and letting it cool slowly.
7. Use the draw plate by placing it in a sturdy bench vice. Thin the wire right at the end so you can get it through a hole in the plate, and pull it through with a pair of pliers. It takes some time to get the hang of getting the end started, through the hole and getting a hold of it with pliers. Try to pull it through without squishing the end of the wire too much during each pull. It is a pretty straightforward process, though, with probably an hour of trial and error. Keep running the wire through a smaller and smaller hole until it is the desired size. Be sure to anneal it if it begins to get too stiff.
Making the 24k sheet and wire yourself will pay for itself quickly. Catch all your 24k scraps and just re-melt, again and again. Any karat less than 24k you cannot do this with, as it will oxidize and make a mess of the gold after a few meltings. 24k is pure and much easier to work with than the lower karat golds.
Link to a gold roll at Gesswein
CAUTION:: Don't set the crucible on your bench and heat it there! It will burn a hole in the bench! I clamp one carefully to a bench vise, and heat it there. 24k gold melts somewhere around 2000 degrees. Very hot! One thing I have heard of that can happen that could be very bad is if the gold is heated so hot that it boils it could POP and splatter all over the place, including your clothing, face and eyes. I'm not sure what temperature you would have to get it to for this to happen, but I've always tried to just get the gold to the melting point and then pulled the flame back a little so as not to heat it much further. I do try to leave it molten for a minute or two, though, to burn any impurities out of it. To be on the safe side, you might want to use a propane torch, as it doesn't get as hot as an oxygen acetylene torch. It takes longer to heat the metal up, but it would be tougher to get the gold to the boiling point with the propane.
Anneal the gold before actually hammering the sheet or wire into
a prepared undercut pocket in your project. Annealing will soften it, and will make it easier to inlay.