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-   -   Using a gold coin for making gold sands? (http://talk.craftweb.com/showthread.php?t=11893)

Josh Bernbaum 03-04-2018 02:50 PM

Using a gold coin for making gold sands?
 
I'm going to see what I can achieve on a couple melts involving gold soon. Would like to hit a nice gold ruby and purple based off a couple of Pete's formulas from the last class. I have all the ingredients and ventilation, perhaps including the gold if you count some "Double Eagle" US coins I inherited a couple years ago. I see on wikipedia that they were minted with a 90% gold and 10% copper alloy. I'm not sure how much value these have on top of the intrinsic material weight, they aren't in perfect condition but I'd check on that before proceeding after asking the question I have: If I do use a coin, or part of one, would I have to make gold "shavings" first or would a big chunk suffice for making an aqua regia? And would the 10% copper content of the coin cause any issues if I'm not planning on doing a cadmium color? Thanks in advance!

Jordan Kube 03-04-2018 04:02 PM

Also curious about gold rubies but it's been 12 years since I took the class and can't remember much of what was talked about.

Eben Horton 03-04-2018 05:10 PM

I’d try to trade them in for pure gold. Why take chances?

David Patchen 03-04-2018 05:44 PM

Why not use 24 karat leaf? It’s cheap for small amounts and it’s pure gold. You can send me the double Eagles :)

Dave Bross 03-04-2018 07:40 PM

You'll need gold chloride, which you can buy, and the info from Pete (who makes his own gold chloride) is here:

http://talk.craftweb.com/showthread....ght=gold+sands

and some more from Pete circa the lost Craftweb archives:

"Gold Sands are sands impregnated wiuth gold chloride. I will have a full lurid treatise on it in my vapor book. Essentially you add gold chloride to silica in a one gram per hundred gram ratio and mix it well. The aqua regia is the carrier for the gold chloride. I mix it up like a very sticky bisquick mix using my very best non leaking rubber gloves. This really stinks and should be done in a very well insulated area.
You will have a LOT of trouble making a gold glass without lead. It can be done but it's weak. It also needs selenium to set the strike crystals in action. I would advise procuring a bit of Lead monosilicate if you are serious. It won't kill you but treat it with respect. Up to 10% in a batch and you can replace the calcium in the glass with lead gram for gram."

More:

http://www.glafo.se/pdf/2005/C_Stalh...red_colour.pdf

Pete VanderLaan 03-04-2018 07:44 PM

leaf is far from cheap. Sell the coins. get 24 karat fine shot. The copper simply contaminates the process and tends to make a color much like like nice motor oil. You need both hydrochloric and nitric to make aqua regia and you can write me privately as to how to use it and what amounts to add to silica to make the sands.

You will get this great stuff and it will run a bit over a buck a pound to get intense color rod. This is for my class students. The hard part is getting the lead.

David Patchen 03-04-2018 07:49 PM

I guess 'cheap' is relative. But I recently found a source for a book of 25 sheets of 24k leaf (3.5" squares) for $38. That seemed incredibly cheap and convenient if you only need a tiny bit of gold.

Josh Bernbaum 03-04-2018 08:16 PM

Thanks for the replies. I found a decent amount of Pb bisilicate a couple years ago. Yeah I could see about selling a coin or two but wondering if Dave's suggestion of just buying some gold chloride instead of buying the 24k shot and mixing my own aqua regia would be a better bet? The chlorides I see for sale online seem to vary from 1% to 8% or so.

Pete VanderLaan 03-05-2018 07:59 AM

Buying gold chloride is an expensive way to do it just as making silver nitrate is far cheaper than buying it, but it does take process. After my first trip to SHanghai, Wang Kai gave me three bottles of gold chloride weighing about a pennyweight each in content. That's enough to process three hundred grams of gold sands. I think it takes about 200 grams to process about 20 pounds of intense color rod. You do have to have the lead.

I get pretty absent minded with this stuff. I lost 3000 grams for about four years, then I misplaced about ten pennyweights of 24K gold which MaryBeth found last week and then found yet another 1200 grams of gold sands I made as a demo to the last color class tucked away by the big ventilating fans.
It's not hard to make. Keeping track of it is my big problem. It's true with silver shot as well.

Josh Bernbaum 03-12-2018 12:47 PM

So if I do buy a bottle or two of gold chloride to save a step here, any recommendations on where to buy? Amazon offer ones that range in price and percentage of gold. Does this one below look okay? It says 5% gold solution in a 50ml bottle, about 5g gold total weight I think it says. Also, why would I need to mix this with more hydrochloric when making the gold sands? It's not sufficient to just pour the little bottle over 500g silica and let that dry? Perhaps the extra HCl is for more even distribution throughout the silica?


https://www.amazon.com/8-625-Chlorid...SR9PR983R0MC5T

Pete VanderLaan 03-12-2018 02:55 PM

Well, look at the price for 24 Karat gold which changes hourly. There are 16 pennyweights in an oz of it. An oz is still 28 grams I think. It could be 30. Adding additional acid for me is just a transportation system for the gold to get distributed evenly if you recall I had gloves and kneaded it like bread dough We all have different ways of doing it. I think John justs dumps his little gold bottle in the mixer

Jordan Kube 03-12-2018 04:28 PM

That bottle contains 2.5 grams of gold. Most recent price for 2.5 grams gold:

https://www.apmex.com/category/19340...ld-bars-rounds

If you were doing a one off thing you might be able to make the case for it but if gold is something you plan on doing a bit of it would make sense to invest in the chemicals.

Kenny Pieper 03-12-2018 04:44 PM

Josh if you look at the description at the bottom it says there is 2.5 grams of gold there. RioGrande's price today for 2.5 grams 24ky casting grain is $120 so the acid might cost $30 at most with lots left over. Its really not hard 2 parts hydrochloric to 1 cup nitrite in borosilica container with the gold, warm it a bit to get it going and wait for it to desolve and you will have your gold chloride. Sounds a bit scary but it is quite simple.

Pete VanderLaan 03-12-2018 04:52 PM

I bite the bullet josh and buy a troy ounce of gold shot. If you don't use it , it's easy to sell the same day based in market. I've made profits on gold but I follow the drill I used in the class and nominally 0ne troy oz makes about 3000 grams of gold sands. They don't degrade but having them dry is really nice when it comes to the screening and you won't have that with the bottle.. It's not cheap but 2.5 grams will make you 250 grams of the sands. The basic formula called for 200 grams of the sands as I recall. Right now I have enough sands to make about 45 pounds of a gold ruby and that's a lot given the concentration of it.

When you buy the bottle, you are paying though the nose for process. It's true with silver nitrate as well. My mom bought me one in 1969 ( I miss mom). It had 1/8th oz of gold in solution. Big present. I didn't use it for 25 years.

I just keep losing the gold Really, I misplace it sometimes for years. I lose everything. There's too much stuff here. Eric shakes his head. Now Mary Beth keeps all that stuff in her special little box since she has no confidence in my stewardship. I have to ask her for it. Since I can't remember what I've been up to, I take great joy in finding a pound of silver in the box that I forgot about. Aging is just part of the multiple grand systems failures. Vision, circulation, hearing, sex, blah blah blah...Parts are hard to get. Learn to do this now is my message. Your mentors are going toes up.

Josh Bernbaum 03-13-2018 09:58 AM

Thanks for the replies everyone, I do respect all of your experience and appreciate your recommendations. I'm just going to buy 4 pennyweights online for now, I think that's all I'll need for the couple small melts I plan on doing first.

Josh Bernbaum 03-13-2018 10:09 AM

Quote:

Originally Posted by Kenny Pieper (Post 138923)
Josh if you look at the description at the bottom it says there is 2.5 grams of gold there. RioGrande's price today for 2.5 grams 24ky casting grain is $120 so the acid might cost $30 at most with lots left over. Its really not hard 2 parts hydrochloric to 1 cup nitrite in borosilica container with the gold, warm it a bit to get it going and wait for it to desolve and you will have your gold chloride. Sounds a bit scary but it is quite simple.

Thanks Kenny, so is that 2 cups HCl to 1 cup nitric acid the volume you'd use for dissolving any amount of gold, or is that specific to 2.5g gold or more? Just curious if the ratio of liquid volume to gold weight is important.

Josh Bernbaum 03-13-2018 10:28 AM

Sorry, one more question. Didn't see much online about where to buy Nitric acid, but did find this. Not sure what kind of concentration we need for the aqua regia, will this do? (my name is prob already on some chemical "watch-lists" so whatever, I guess..)

https://www.sciencecompany.com/Nitri...0ml-P6387.aspx

Kenny Pieper 03-13-2018 12:53 PM

Quote:

Originally Posted by Josh Bernbaum (Post 138936)
Thanks Kenny, so is that 2 cups HCl to 1 cup nitric acid the volume you'd use for dissolving any amount of gold, or is that specific to 2.5g gold or more? Just curious if the ratio of liquid volume to gold weight is important.

I use about half that to do 10 grams gold. I think Pete said once he uses 2 cups HCI to 1 cup nitric for 30 grams. Pete?
I don't think the proportions are very important.

Pete VanderLaan 03-13-2018 12:56 PM

I recently bought Nitric and had a good deal of difficulty doing it since my address was not viewed as commercial. I mean I couldn't get anyone to do it until.... ( amazingly) Graingers. It arrived without issue. You may have the same issues, so a simple heads up.

The two cups hydrochloric to one part nitric was based on using an oz of fine gold ( and do buy fine gold shot 24K). In any of my ventures making the chloride, it was a slower reaction than the one for silver nitrate taking two days.
So, the excess acid won't hurt you but do take note of handling the gold sands. If you run them through a sieve which you really should or they clump badly, really wash that sieve when you finish or you will find the acid has made short work of it and it has a big gaping hole in it. You might wonder why I know that. I mixed the solution up in a regular Erlenmeyer flask which is a boro glass.

The extra acid will make it far easier to mix the fluid easily into the silica but no, you don't need it. It could be an issue where the sands are just sloppy wet since normally an oz of gold goes into 2800 grams of sand. The formula you got from me called for 240 grams of the gold sands which would have used 2.4 grams of gold. I checked this morning. If you use more gold, the ruby gets far darker.

Josh Bernbaum 03-14-2018 07:46 AM

Okay thanks for those answers. Sorry to keep asking, but shopping for the nitric maybe isn't so straightforward. Grainger do seem to have on their site, but there are at least 3 options of strength, and not sure what would be best. From weakest to strongest, the concentrations they offer seem to be: 0.1N, 6.0N, and 15.8N/"concentrated". Not sure which to choose. Also Pete, are you saying this reaction will take more than two days? I was hoping to just leave this outside somewhere, but will the cold/freezing weather be an issue? If it's indoors, can I cover the container, or do I have to deal with the fumes for days if it takes that long? Thanks

Pete VanderLaan 03-14-2018 08:57 AM

Normally the highest concentration is 70%. get the highest.

Don't put it outside but it's OK to cover the flask with a-non ferrous cover. It needs to happen as just warm It should take two days though. I'd just put it under the furnace around the back. It's not a violent reaction at all and it isn't really pungent either. The gold shot will just keep getting smaller and smaller. The worst part is putting it in the sand and mixing evenly. Take that outside to do. then bring it bck in and cover the sands and put them in a warm place of they'll never dry. Once dry, screen it. The really wash the screen.

So now I'll tell you a funny story doing this.

At one point I had an employee who did not take direction very well. I mixed up the slop and asked him to put it somewhere warm. He did. He put it on top of one of the main furnaces. The flask tipped over and ate a hole entirely through the crown. I don't know why they call it "Help".

Josh Bernbaum 03-22-2018 10:50 AM

I paid about $30 for a bottle of nitric acid, and about $55 to ship it here. (hazmat charges)..

Pete VanderLaan 03-22-2018 11:32 AM

you can use it to make silver nitrate too. I don't recall hazmat charges my last time. If it's a 4 liter bottle it will last you a long time.

Eben Horton 03-22-2018 03:25 PM

Make sire you say in a meniacle and dark voice - “let’s cook” before you make the silver nitrate.

And if you get in trouble... you better call Saul.

David Hopman 03-23-2018 06:16 PM

31.1 grams to a troy ounce. And 12 troy ounces to a troy pound. So a pound of feathers really does weigh more than a pound of gold.


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