Non-Chemical What is a good method for combining gold powder and a button

[skyline27]

What is a good method for combining gold powder and a button into one button?

Thanks!

 

[Lou]

Melt the button and add the gold powder.

 

[Noxx]

Or melt the gold powder then add the button.

 

[grainsofgold]

If I was doing it I would roll the button out flat and cut the thin sheet into pieces and place the pieces over the dust then melt it. The thin sheet will melt faster and tend to absorb the gold dust in the melt.

Grains of gold

 

[Harold_V]

If I was doing it I would roll the button out flat and cut the thin sheet into pieces and place the pieces over the dust then melt it. The thin sheet will melt faster and tend to absorb the gold dust in the melt.

Grains of gold

While there's nothing wrong with your idea, it's one hell of a lot of work that isn't necessary. If you melt a button first, any powder that is added to the super-heated button will melt instantly and be absorbed. No need to go to all the trouble to roll the gold. A button of gold, being an excellent conductor of heat, melts fine as long as you have an adequate heat source.

It makes no sense to melt powder before melting a button. You can't safely dump a button in a pool of molten gold, but powder dumped on a molten button works very well.

I always force dried my gold, heating it to well beyond the boiling point of water.

Harold

 

[Rag and Bone]

How do you "roll" gold anyway?

 

[Harold_V]

Jewelers use rolls to make stock for fabrication. A pair of hardened steel rolls, gear driven, both hand and motor powered are on the market, although powered rolls are quite expensive. Hand rolls cost under $1,000, or at least they used to. Italy made some very nice equipment. My power rolls were Italian.

The top roll is adjustable, so you can control the thickness of the rolled material. It's not a big deal to roll both pure and alloyed gold and silver, but you have to anneal between rolling sequences, otherwise the material, even pure, work hardens. It becomes too hard to roll, and will split instead of reduce in thickness. That's why I suggested rolling was not a good use of your time when you want to melt gold. Too many added steps that are totally without benefit.

Harold

 

[Irons]

Has anyone tried swaging the gold powder directly into a round or slug. Powder Mettalurgy is pretty common these days. I bet pure Gold powder could be easily swaged into an ingot without much trouble. The nice thing about the technique is that you can weigh out an exact amount of powder.

An arbor press is pretty easy to make.

BTW, I saw an Indian made hand rolling mill on Ebay the other day for $188. It includes extra rollers with patterns.

 

[goldsilverpro]

I agree with Harold. Rolling the button is a total waste of time. Like he said, melt the button first, and then add the DRY powder.

Never add anything containing moisture to molten metal or molten slag. It will spit and cause metal to be thrown out of the dish or crucible. I have seen the ceiling above the furnace covered with silver BBs burned into the wood. Luckily, the operator didn't have his head over the crucible when it blew. I used to routinely add damp materials, always wrapped in filter paper, to a hot crucible. But never to molten metal or slag. If the metal and/or slag was molten, I removed the crucible and allowed it to cool enough to completely solidify before adding any damp material.

Also, never add moist material to a cold crucible. The moisture can quickly soak into the crucible and cause it to split. I have seen silicon carbide crucibles split into 2 crucibles, one inside the other. Get the dish or crucible good and hot first.

I really shouldn't be telling you these things. It's definitely better and much safer to dry all materials thoroughly before they are melted.

 

[Irons]

I really shouldn't be telling you these things. It's definitely better and much safer to dry all materials thoroughly before they are melted.

I learn more from my mistakes than from things that turned out right without knowing why they did.

Thomas Edison tried a thosuand ways to make a light bulb before he was successful. He said he learned 999 ways not to make a light bulb in the process.

 

[goldsilverpro]

Irons,

Once, I saw an industrial need for a consistent weight gold pellet for use in the sputtering or evaporation industry. I got a small pill press and used gold powder to produce some 1 gram gold tablets. I then took them to one of these companies to try them out. They didn't work. They had trapped air in them and exploded when melted in the vacuum chamber. I could have pressed them in a vacuum, but that was too much of a pain to set up.

 

[Irons]

Irons,

Once, I saw an industrial need for a consistent weight gold pellet for use in the sputtering or evaporation industry. I got a small pill press and used gold powder to produce some 1 gram gold tablets. I then took them to one of these companies to try them out. They didn't work. They had trapped air in them and exploded when melted in the vacuum chamber. I could have pressed them in a vacuum, but that was too much of a pain to set up.

I could see how that would be a problem.

Pressing them hot might solve that.

 

[goldsilverpro]

Maybe. Sintering in a vacuum might also work.

 

[Irons]

Maybe. Sintering in a vacuum might also work.

Not melting it in a vacuum might help as well.

A porous, low density press, just enough to hold the Gold together so it doesn't blow away in the torch flame might be an idea.

 

[grainsofgold]

The reason I like rolling out metal into thin pieces is that it helps keep the entire mass fully melted rather than only heating up to melt say the top half of a button- I am talking about large batches that I have mixed-

But as others have noted it is work, but if simply melting the button works for you then by all means stick to that process-

There are many ways to do the same thing- or skin the cat that is

I think that we all agree melt the button then add the powder into the pool of gold-

 

[docone31]

Maybe I can help here.
I use denatured alcohol and boric acid, cockroach killer.
I mix the boric acid in the alcohol in small quantities. I primarily use this technique as anti-firescale when I resolder prongs or heat a ring that has and high temp stone.
With the powder in a filter, dip it into the alcohol mix. I like fire so I ignite it in my crucible, otherwise, let it dry and fire it.
The boric acid melts and makes a flux while the powder is getting hot. The contaminants of the filter act as charcoal and deoxidise while melting. Borax can also be added to the boric acid and alcohol mix.
This method works pretty well with me on shop sweepings from my drawer.
I have also picked up my powder with beeswax and then fired it with the boric acid solution.
It seems the boric acid prevents the powder from flying out from the pressure of the torch.
On another note, is it possible to just toss my bench sweepings into muriatic acid/chlorine and get auric chloride solution?
A rolling mill is now very inexpensive. Without putting an URL on the forum, search mini rolling mill. Should be about 185$. Works real for me in my shop for rolling out sheet stock. I wouldn't use it for prescision as it is course in adjustment.