Non-Chemical how to clean silver&gold ingot from borax glass

[joheleh]

hi, i've tried to search here on the forum but i didn't found nothing specific. How can i clean respectively silver and gold ingots from borax glass? what acid baths can i use?

 

[FrugalRefiner]

Try your search again. Search for the words - remove borax. I found several relevant hits on the first page of search results.

Dave

 

[samuel-a]

You can use an air needle gun if there's a lot of slag and finish off with hot dilute (10-15%) sulfiric acid.

 

[Harold_V]

I'm curious why there's flux involved. I cast a reasonable amount of gold and silver in my years, never using any flux for the purpose. If your metals are pure, there is NO need, aside from a thin film in the melting vessel, which behaves as a lubricant more than anything. None is transferred to the ingot when you do it "right".

Harold

Thanks, Frugal, for catching my mistake.

 

[joheleh]

I'm curious why there's flux involved. I cast a reasonable amount of gold and silver in my years, never using any flux for the purpose. If your metals are pure, there is NO need, aside from a thin film in the melting vessel, which behaves as a lubricant more than anything. None is transferred to the ingot when you do it "right".

Harold

I understand that, but i've made i little mistake seasoning my silica melting dish, i putted too much borax. In the first pouring there are always some drops of flux that goes into the mold, so my ingots are a lil bit dirty, just a little. By the way, i noticed i can clean gold ingots with a diluted nitric solution, i still have to clean the silver ones, i don't have sulfuric acid right now, so before making HUGE mistakes i was wondering if HCl will work as well as sulfuric for silver.

 

[Palladium]

I'm curious why there's flux involved. I cast a reasonable amount of gold and silver in my years, never using any flux for the purpose. If your metals are pure, there is NO need, aside from a thin film in the melting vessel, which behaves as a lubricant more than anything. None is transferred to the ingot when you do it "right".

Harold

I understand that, but i've made i little mistake seasoning my silica melting dish, i putted too much borax. In the first pouring there are always some drops of flux that goes into the mold, so my ingots are a lil bit dirty, just a little. By the way, i noticed i can clean gold ingots with a diluted nitric solution, i still have to clean the silver ones, i don't have sulfuric acid right now, so before making HUGE mistakes i was wondering if HCl will work as well as sulfuric for silver.

No! Hcl will turn the silver black.


http://youtu.be/K2YLSZ-kj0M

 

[truandjust]

I've used citric acid for removing flux with success.

 

[kadriver]

In the search block in the upper right of your screen, type in the words, "10ml sulfuric" then press search.

There is a thread that tells exactly how to remove the borax that adheres to your ingots, it does involve using sulfuric acid but it very effective.

Sulfuric acid will dissolve silver to some extent so use gentle heat and don't let the silver sit in the solution too long (5 minutes on low heat, then remove from acid bath and gently rub the borax off under warm running water).

The acid will ruin the finish of your silver bars if they are left in too long.

I also put gold bars in this same 5% sulfuric acid solution, they can sit overnight and come looking very nice.

kadriver

 

[MysticColby]

can confirm sulfuric affects surface of silver - it takes a while, and usually at higher concentrations. sometimes it makes them look awesome (surface looks like reflective crystals), sometimes ugly.
dilute sulfuric does great at removing borax, but I seem to remember that I tried dilute acetic acid at one point... I forget how well it worked. to get acetic acid, just go to the grocery store and buy a gallon of white vinegar for like $1.13

 

[Maget]

I've used citric acid for removing flux with success.

I have think citric acid is Vinegar so I used it and worked for me better than sulfuric, even no need to heat just leave for some hours and it dissolves away.