Non-Chemical Ingot advice anyone

[scaryfastg]

I am using an oxy-acetylene torch with #2 welding tip. I am melting 14k scrap in a fused silca dish and pouring into a graphite mold.

Something is wrong with my technique. The bottom of the ingot(top when pouring) is not smooth at all. It is rough, bubbly, and uneven. I am using borax.

How do I get a nice looking ingot? Is there a problem making 14k ingots? Is the gold solidifying to fast? Is a #2 victor type welding tip big enough?

Thanks

 

[butcher]

Base metals oxidize, gold hardens, normally 14K is NOT re-melted and reused and jewelry formed, because of problems you have noted and problems later forming the jewelry article, you should refine your gold, and then take pure gold and the base metal or silver needed to make 14K again, or sell the scrap 14k piece and buy more pure gold.

Harold and Nick V have discussed this problem you’re having many times, reading these posts will help you better than I can; I am just a parrot of what they have discussed with others and this problem.

Gold melted if pure (not pure, base metals eliminated) needs only enough borax to wet melting dish, too much borax can make gold beads form in glass flux, a hot dish and getting gold very molten also helps how the melted gold appears, and if pouring must be kept hot enough that it will not solidify during pour, melting dish setting on a large heat sink which can absorb your heat should also be avoided.

Laser Steve’s web site provides a great search engine for the forum.

 

[element47]

Just for my own reference, about how long do you have to heat your 5 oz of material to melt it using that torch?

As for my questions/suggestions, what type of flame are you using? Are you using a reducing flame? A reducing flame will have a larger, internal feather. This is different than the type of neutral flame used when gas-welding steel, which will have a sharply defined inner cone. I think you would want to use a reducing flame, but not so much excess-acetylene that you get a lot of smoke or soot. It may also make sense to back down to a #1 tip and operate it at a higher flow so that the feather is larger.

Apologies for the crappy diagrams, but they should be sufficient.

And I have to wonder if you would better off with oxy-propane, because you could be boiling some of your alloying metals in the temperatures produced by acet.

 

[scaryfastg]

Yes I am using a reducing flame. It takes about 3 minutes to melt to a very fluid state with my #2 tip.
So then it is harder to make a good looking 14k ingot than say a pure 24k ingot. I will search for hardold+nicks posts on this subject. Thanks

 

[nickvc]

It sounds as if either the melt is too hot or you have borax bubbling through your melt. Try using less borax and pour your melt when all the metals become fully molten, over heating might be causing base metals to oxidise and burn off. Another trick to try might be to keep a lower flame over your ingot as it cools.

 

[jimdoc]

Scaryfastg,

You should not edit out the pictures, or any other details in posts once you get answers because it leaves the whole post lacking detail for others to learn.

Jim

 

[Harold_V]

Scaryfastg,

You should not edit out the pictures, or any other details in posts once you get answers because it leaves the whole post lacking detail for others to learn.

Jim

I am of the opinion that anyone that edits posts unnecessarily should be banned from the forum. Altering posts tends to render a thread useless.
Good call, Jim.

Harold