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[Greasemonkey80]

Hello, I was wondering if anyone could help me. I have some glass window panes that have gold leaf on. I am repurposing the glass and I am scrapping off the leaf. Just to satisfy my curiosity I tested the scrapping with my test kit and it shows to be around 18k. I have a lot of these to scrape off for the past few years I have been looking into refining gold from circuit boards but I have never done it. What would be the best way for a beginner to go about recovering the gold from the backing?

 

[Ohiogoldfever]

Photos would be helpful. I’m sure once folks have a look they can advise if it’s worth chasing and how to go about it.

 

[goldshark]

Gold foil, the thicker then Gold leafing by about 20 microns, covers about 16 square feet per Troy ounce. If it is Gold leaf, you will have to have at least about 50 square feet of leafing to get an Oz.. Leafing and foil is applied with something called Gilding size. It is composed of Linseed and Tung oil, as well as Phenolic resins and Ester gum, and mineral spirits. So a good heat gun and a single edge razor blade should make the quickest work of foil removal. After heating and scraping, your choice as to using AR or AP, denoxing, SMB drop with fitering, yatta yatta yatta.. You have more time than me, let us know how it works out please. You don't want to over heat the glass too much or it will break. heat and scrape after a little trial and error, you will find the most efficient heat time, then scrape rhythm.

 

[nickvc]

Welcome to the forum.
Do your research before trying any chemical processes and the good news is that it’s all here for free on the forum.
For thin materials like leaf or foils I would advise to incinerate them first and then use HCl with either hydrogen peroxide or bleach but be aware that dissolving gold by any method produces toxic fumes .

 

[Greasemonkey80]

Photos would be helpful. I’m sure once folks have a look they can advise if it’s worth chasing and how to go about it.

Here are some pics so you can see what I’m up against. I have roughly 150 of these pieces of glass. They measure 18inches (45.72cm) by 12 inches(30.48cm) the container that the scrapings are in is a one pound cake iceing container. That is about 25 windows worth of gold leaf. So if it really is 18k gold would it be worth it to refine it? I already have to scrape it off so that is not a factor as far as labor goes. Would the process be simple enough for a beginner to do. Just fyi I’m not a chemist by no means I’m a tinker’r and a equipment mechanic but I know enough to know that I don’t know much and I respect the process and the chemicals I don’t go mixing everything together unless I know what to expect through the marines corps I was fortunate to go through just about all the nbc classes. To the point if I would have went to one more they was going to change my job to one in the nbc field. I do have a good grasp on how dangerous chemicals can be and how easy it is to make a mistake with mixing them.

 

[Greasemonkey80]

Welcome to the forum.
Do your research before trying any chemical processes and the good news is that it’s all here for free on the forum.
For thin materials like leaf or foils I would advise to incinerate them first and then use HCl with either hydrogen peroxide or bleach but be aware that dissolving gold by any method produces toxic fumes .

Thanks, yeah I don’t plan on mixing anything together or attempting anything untill I know the process and the safety precautions that I will need to take. I have had an interest in gold recovery for a wile now and all I done is research that’s what lead me to this forum. And it is a godsend when I get time i and I remember about it I read through threads in an attempt to learn something. I do thank you for the warning.

 

[Greasemonkey80]

Gold foil, the thicker than Gold leafing by about 20 microns, covers about 16 square feet per Troy ounce. If it is Gold leaf, you will have to have at least about 50 square feet of leafing to get an Oz.. Leafing and foil is applied with something called Gilding size. It is composed of Linseed and Tung oil, as well as Phenolic resins and Ester gum, and mineral spirits. So a good heat gun and a single edge razor blade should make the quickest work of foil removal. After heating and scraping, your choice as to using AR or AP, denoxing, SMB drop with fitering, yatta yatta yatta.. You have more time than me, let us know how it works out please. You don't want to over heat the glass too much or it will break. heat and scrape after a little trial and error, you will find the most efficient heat time, then scrape rhythm.

I wouldn’t say I had more time. I got about 150 of these glass panes to scrape. Lol that should have quite a bit of gold leaf/foil

 

[Greasemonkey80]

If there are any shortcuts to threads that would be helpful with the task at hand it would greatly appreciated

 

[FrugalRefiner]

Have you tested and confirmed that these are gold goldleaf? There are copper based alloys that are very good imitations.

Dave

 

[eaglekeeper]

Dissolve some foils with a milliliter of hydrochloric acid (muriatic acid) and a couple of drops of house hold bleach. Give it 5 minutes and then test with stannous chloride, if there's gold you'll know pretty quick.

Do it outside or in a fume hood...hydrochloric acid fumes are pretty pervasive and will rust anything with in 50 feet.

 

[Greasemonkey80]

Have you tested and confirmed that these are gold goldleaf? There are copper based alloys that are very good imitations.

Dave

Yes I have tested the foil. I’m still pretty new to the whole process but I took some of the scrapings and put the on my test stone and put a few drops of the test solution on them it was easier to see on the bigger pieces but I used a small piece of plastic to move the sample around in the acid and with the 18k solution the gold dissolved off the backing. Would copper dissolve in the acid same as gold?

 

[Yggdrasil]

Yes I have tested the foil. I’m still pretty new to the whole process but I took some of the scrapings and put the on my test stone and put a few drops of the test solution on them it was easier to see on the bigger pieces but I used a small piece of plastic to move the sample around in the acid and with the 18k solution the gold dissolved off the backing. Would copper dissolve in the acid same as gold?

What will dissolve Gold will also dissolve Copper.

 

[Greasemonkey80]

What will dissolve Gold will also dissolve Copper.

Well that’s not what I really wanted to hear. So maybe it’s back to square one. If I dissolve some of the foil in muratic acid and add a couple drops of bleach. ( as described above ) what reaction will the stannous chloride have? What will be looking for? Would this be a better way to tell if the foil gold or some other metal?

 

[Yggdrasil]

Well that’s not what I really wanted to hear. So maybe it’s back to square one. If I dissolve some of the foil in muratic acid and add a couple drops of bleach. ( as described above ) what reaction will the stannous chloride have? What will be looking for? Would this be a better way to tell if the foil gold or some other metal?

If there is Gold, the drop will turn Violet more or less immediately.
Many ways to do it, plastic spoon, paper strip, cotton bud or any small container.
But for ease of interpretation, it is best if it is white.
Add one drop of solution to it, then drip a drop of stannous in/on the edge of the drop.
If its too concentrated it might look black, then dilute it with water and try again until you see the real color.

 

[Greasemonkey80]

If there is Gold, the drop will turn Violet more or less immediately.
Many ways to do it, plastic spoon, paper strip, cotton bud or any small container.
But for ease of interpretation, it is best if it is white.
Add one drop of solution to it, then drip a drop of stannous in/on the edge of the drop.
If its too concentrated it might look black, then dilute it with water and try again until you see the real color.

Awesome! Thank you. I know I can go get muratic acid and bleach for the store. But can I buy stannous from a local store or is it easier to order on-line. I seen it on a link attached to the forum.

 

[FrugalRefiner]

When you're at the store, buy a little solder. The higher the percentage of tin in it, the better, but any solder will work. Dissolve some of the tin in the same muriatic acid (no bleach needed). Put the tin in a tiny bottle, add the HCl, and warn it a bit till it starts bubbling. Leave it uncapped till it stops bubbling. The HCl creates fumes that destroy most metals, so keep it all away from anything you don't want destroyed.

Dave

 

[Christian333]

Yes I have tested the foil. I’m still pretty new to the whole process but I took some of the scrapings and put the on my test stone and put a few drops of the test solution on them it was easier to see on the bigger pieces but I used a small piece of plastic to move the sample around in the acid and with the 18k solution the gold dissolved off the backing. Would copper dissolve in the acid same as gold?

Try using the silver test reagent, it is nitric acid based and will dissolve all base metals, leaving gold in foil or particulate form.
Put a tiny sample in a plastic spoon or on your scratch stone, add a drop and observe.

Janie

 

[eaglekeeper]

He has an excellent YouTube channel.... Like and subscribe to his channel.

You don't necessarily need stannous chloride crystals or pure tin..... solder will work fine.

 

[Daniel0007a]

Good luck. You can use Nitric/HCl to dissolve the copper but leave the gold in the solution. Often Nitric alone 68% can dissolve the copper and leave you with gold. Bleach and HCl would produce chlorine that would drop out gold if you used SO2 gas. (SO2 gas generator with Sodium metabisulfite and Acid). A tin (2) chloride test or a gold test kit would be recommended for other metals.

Unless something is stamped on eBay and is pure gold i would not buy that from ebay. Lots of Chinese sellers will sell Brass and pass it off as gold.

 

[Yggdrasil]

Good luck. You can use Nitric/HCl to dissolve the copper but leave the gold in the solution. Often Nitric alone 68% can dissolve the copper and leave you with gold. Bleach and HCl would produce chlorine that would drop out gold if you used SO2 gas. (SO2 gas generator with Sodium metabisulfite and Acid). A tin (2) chloride test or a gold test kit would be recommended for other metals.

Unless something is stamped on eBay and is pure gold i would not buy that from ebay. Lots of Chinese sellers will sell Brass and pass it off as gold.

You need to stop posting incorrect information. Study more please.

You can use Nitric/HCl to dissolve the copper but leave the gold in the solution. This is AR and will dissolve it all. This comment to the quote is wrong due to misunderstanding.

Bleach and HCl would produce chlorine that would drop out gold if you used SO2 gas. Bleach HCl will dissolve the Gold. SO2 are generated in situ by SMB in an acidic environment no need to set up a generator, but sometimes it may be handy, if you use your Nitric correct SMB alone is sufficient.

Bold text in quotes is my comments, underlined text are wrong information
Bold red is my reply.

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