home made cupels

[viacin]

lol, gotta watch those fumes bud...

maybe no one has any for sale at the moment. I still see HCl and sulfuric acid for auction, although for almost twice the price you pay at the hardware store.

 

[bmgold]

I found the link again on nitric acid on ebay. It has ended but WAS on there. I didn't make it up afterall.

260268502825

Username : dudadiesel

Keep watching this user or maybe send him a message to get another batch listed. Maybe he is just out now or didn't get any responses or maybe he will list more soon

Just a thought

 

[viacin]

hey, thanks for finding it. That's the same guy that sells sulfuric acid too. 1 gallon for $56 is cheaper than anything I've seen, but still not as cheap as making it yourself.

He says "does not ship with bases", like sodium nitrate. But I wonder if he has thought about shipping it with his sulfuric acid. If it spilled out and mixed with the cardboard box he would have a big 'ol batch of guncotton

 

[DarkspARCS]

ok... fine. I'll be the first n00b to post here. Laser Steve, is the offer of free cupels to the first 5 n00bs who post here still good? :twisted:

We're almost out and we have so much ore testing left to do lol... :roll:

 

[AndyWilliams]

'The Crotchity Old

I resent you stealing my title! :lol:

Harold

Nonsense! You're the crochEty one, kind of like the difference between Sodium Metabisulfite, and Sodium Metabisulfate!

 

[Pogo]

Hello,
This comes from my book; Fire Assay, by Orson Cutler Shephard and Waldemar F. Dietrich Copy right 1940: Portland cement alone is sometimes used for assay cupels; it is more commonly used with various percentages of bone ash. When cement is used as all or part of the cupel composition the amount of mixing water should be 8 to 12 per cent. Less or more cause the cement to check or crack on heating. Pure cement cupels give higher cupellation loss than do bone ash cupels, but mixtures of cement and bone ash up to 75% cement give as low a percentage of losses as those made of pure bone ash. Have fun!

P.S. It took me two years to puzzle out how to perform a fire assay. I found this book in a Colorado used book store about four years after (I thought), mastering the process. This book has helped greatly, is probably one of the books you'll never find in the library, and goes into fire assay with such scope and depth that I feel overwhelmed.

 

[jstreet]

I've been reading up a bit on making my own cupels. Doesn't seem like the recipe is too hard -- or making the form to pack them.

Just wondering if any of you folks have tried this with any success and have some things to watch out for.

Mixing just the right amount of water seems like the first challenge.

Seems too that using a home made cupel just might add to few craked or broken experiments.

I'm thinking I can make a few and do some tests with just lead and no precious metal to see if I'm getting it right. I'll be doing a few things in the summer when the conditions are right to be playing around with fire and chemicals. One of my other projects will be a furnace.

Any info would be appreciated.

Thanks
Steve K

My wife has Cancer and don't have money to order things.I had a bunch of older computer mother boards and friend gave me some acid which I was successfully in extracting some gold.I now need to melt it but I'm wondering what to melt it in.I had some silver and tried to melt on piece of metal, big mistake.I now have about two Oz's of silver stuck to angel iron.what is cheapest way to make cupel.I looked in town but can't even find one

 

[FrugalRefiner]

If you're just trying to melt some gold, you don't need a cupel, you need a melting dish. They are available of eBay for just a couple of dollars. In your circumstances, if that's still too much you can try digging a small hollow into a piece of charcoal or possibly a piece of drywall scrap. It's not the best solution, but it can work for small amounts. A small melting dish will work best.

Dave

 

[Shark]

You can use a grinder and grind a small dish in a hard fire brick, heat and coat with 20 Mule Team washing powders (borax) which will turn into a glass looking substance (use just enough to coat the dish), put your gold in and melt. The hard brick does take some heating as it is designed to absorb heat. I like the clay dishes but they do need care in seasoning them before use. I once used one for over year and it only coast $2.65.