Assay cupels- melting dishes

[socorban]

I had 3, dropped one, the other cracked over time and my last one is about spent.

Any one know were i can get decent priced assay cupels "melting dishes"

I checked ebay and didnt find any decent ones, most are single ones for 10 to 20 bucks, or ones with handles, i already have tongs for cupels and the type in the listings with the wingnut grips.

I really need cupels! any info on a place with good prices on quantity would be most appreciated!

 

[lazersteve]

Socorban,

I'm waiting on a new batch of 40. I get them for a little more than $2 each.

I'll let you know when they come in.

Steve

 

[socorban]

Thanks steve, keep me posted.

they seem to only last a few smeltings. Is that normal? I think my old ones are bone ash, is clay or silica better?

I was told graphite are the best crucibles to use and most durable but from what i seen they drain you wallet as well.

 

[Noxx]

Steve,
I may be interested into your cupels if you have some for sale.

 

[lazersteve]

I just closed the deal on 40 magnesite (the good ones 4-6 uses) cupels. Ill have them in in a few days.

Steve

 

[Harold_V]

Give this idea some thought:
If you can wean yourselves from using cupels (they're very good at removing unwanted contamination, so that may be a big step), you can use small melting dishes made of clay----readily available from jewelry supply houses. That's all I used, aside from running a #8 crucible in my melting furnace.

There's a couple things you need to know about using the dishes------one is that they will crack if not dried before applying heat---the other is they work very best if they have a thin coating of borax applied before you put them to work, then you have to replenish it as it becomes contaminated with oxides. Once the dish is dark and sticky, it can be cleaned with soda ash, which will usually yield metals from the dirty flux, and a clean dish, back to almost bone white. More borax and the dish is ready to go again, although it will have lost some of the wall thickness to the soda ash.

The dishes are available in at least three sizes, so it's a good idea to buy a few of each. The largest one will accommodate at least ten ounces of gold-----and is the size I used to melt my final product. I did that by torch, which doesn't take long when the gold is perfectly clean.

Harold

 

[socorban]

My only problem is i moved to a new place in the middle of nowhere in the mountains, i dont know of any jewelry supplies stores within a 2 or 3 hour drive from me. I know of jewelers but no supplies so im in a pickle.

 

[lazersteve]

Harold,

Thank you for the great advice. I have just started to move to these melting dishes when I realized the limits of the cupel. I'm not totally weened of the cupel, and probalbly never will be, but I'm on that long road.

You can see the crack Harold talks about (whoops!).

Thanks for the cleaning tip Harold, I'm going to clean mine up tonight.


Steve

 

[Harold_V]

My only problem is i moved to a new place in the middle of nowhere in the mountains, i dont know of any jewelry supplies stores within a 2 or 3 hour drive from me. I know of jewelers but no supplies so im in a pickle.

I talked about a book on refining in a couple other posts, and recommended a source for the book. Rio Grande Supply, although that may not be the proper name. Rio Grande, for sure, is. It's the last part of the name that leaves me wondering. They're in New Mexico, and should have the dishes I spoke of. If not, I can find a source for you if necessary. You might try going online to see if you can find Rio Grande. If so, you might be able to buy the book (I recommend it over any other single book there is regards learning to refine) and melting dishes, too. They used to come two ways-----an off white clay, and a light brown clay. The off white dishes are superior by a long shot----so try for them. I believe they were made under the Vigor name, but I'm not sure.

Harold

 

[Noxx]

Is it this book ?
http://www.lmine.com/Merchant2/merchant.mvc?Screen=PROD&Store_Code=LMS&Product_Code=17208

 

[Harold_V]

No, the title in question is Refining Precious Metal Wastes, written by C.M. Hoke.

Could be the book you found would serve well, but I hesitate to say considering I have never seen it.

I know Hoke's book and respect it (and him)------considering he took me from a machinist that had nothing more than a high school education with no chemical training to a refiner with a business that had a customer base in several states.

I've seen a different book that was horrible-----and --in fact, own the book. You do have to be somewhat careful, for there are more than a few guys out there that don't have a clue, but don't know that. You can be lead down a path that can be costly----but---worse than anything, learn bad habits that aren't in your best interest---some of which you may hesitate to abandon, if for no other reason, they're comfortable, in spite of being less than acceptable.

Harold

 

[Noxx]

I looked around on google and I only found one copy of the book for 75$. I think it expensive for a book. Maybe it is rare ?

 

[goldsilverpro]

Try these guys for cupels, crucibles, and lots of other neat stuff you could use. If they still produce a catalog, try to get a copy. It seems to have more stuff than the website.

http://www.lmine.com/Merchant2/merchant.mvc?Screen=CTGY&Category_Code=assay

 

[goldsilverpro]

You can find Hoke's "Refining Precious Metals Wastes" here - scroll down - 5th from bottom. Well worth $74. In the early '70's, long before it was republished, our company thought enough of it to pay $500 for a photocopy. Keep in mind, though, that it mainly involves jewelry scrap.

http://www.ipmi.org/publications/index_non.cfm

 

[lazersteve]

I just missed out.

I ordered Hokes book last week from Amazon for $120 shipped. I still haven't received the book. The projected arrival date is by mid April.
If I would have waited for your post I could have saved some cash.
Oh well, at least I'll have my copy then.

Thanks for the great work goldsilverpro, you are definitly doing this forum justice in the short time you've been here.
Thanks for the tips on the silver process as well.
Keep up the good work!

Steve

 

[Anonymous]

most public libraries have a loan a book prgram . that and my brothercopy/scan/disk or print free books :roll: it has been sugested I clarify this its called inter library loan program my lib borrowed hoake from university of ariz for me sent me a pick up notice and i had the book 2 wks watch the due date fines are a FRN a day

 

[istari9]

This link is a jewery supply house with free cats and all the tooling you can use. Check them out
http://www.stuller.com/products/