Newbie: melting 925 silver into ingot

[boochieboy]

Hello everyone! I have been following these boards for a few months now (although this is my first post), and the knowledge shared on here is unbelievable. First off, thank you for the site....it is definately THE place to go for this type of information and experience. I started buying 999 silver ingots a few years ago for the simple reason that I thought it was a neat little hobby. As I have gained knowledge about precious metals, they started to interest me further, and I wanted to start learning about refining and recovery from scrap materials. I have never refined any gold or other metals, but I have collected many computers, telephones and other electronics over this past summer, and recently dismantled them all, and sold off the boards, processors etc. to refineries. As I have learned about the process, and chemicals needed to refine the metals, I have decided that it is beyond my skill and patience level to do so....but I still love my metals! My main area of interest is finding scrap sterling silver, and melting it into bullion to add to my collection of .999 ingots(unless it is worth more as a collectible piece than it's melt value). I recently went to a church sale and picked up 3 sterling demitasse spoons for $2 each (I knew they were worth much more,,,even in melt value),,,,,,they weighed in at 12, 14, and 17 grams. Not too bad getting 43 grams of sterling for $6! Anyhow, I am keeping the clamshell spoon because I like the looks of it......one has already been melted down into a button with some scrap sterling jewelry, and the other will also be melted. I am working with simple propane,,,a silica melting dish (which has been properly seasoned),,,and a wooden ingot mold I made and sooted with a candle flame. I do have one quick question though.......is the melted borax already in my melting dish enough for a 38 gram melt, or should I add more as I'm melting? Also, is there any sort of calculator or chart which would tell me how much .999 silver to add to pre-1964 US coins to bring them up from 90% to sterling? Any tips or suggestions for a novice is greatly appreciated.

1 Spoon and scrap jewelry melted into a button (uncleaned borax/flux still on it)

Spoon on left will be melted with the button and poured into wooden ingot mold

 

[jimdoc]

I think you are better off leaving marked sterling items as they are instead of melting them.It will be much easier to sell them as people will know the purity.When it is a melted button or ingot,that would be a total guess,and they will guess on the low side without an assay.So when your time and fuel for the melting are considered you will be losing money.
Steve's video will show you how to refine it pure,and is well worth the money,as are all his videos.

Jim

 

[qst42know]

No need to soot the wood it will catch fire as soon as you pour. I don't know what the epoxy and the glue in plywood will do though. A wood mold for silver is pretty much one shot for small amounts.

 

[goldsilverpro]

I think that's the first time I've heard of a wooden ingot mold. If it's been mentioned before, I must have skimmed over it. At first glance, it seems like foolishness. I can't imagine it holding up for even one melt. Who knows, though, I've been fooled before.

 

[qst42know]

It's a very ancient jewelers technique, perhaps one of the oldest. :wink:

 

[boochieboy]

The ingot mold is made from solid poplar wood pieces with a polyurethane based glue. A hardwood would be better, but I didn't have anything on hand. It wasn't designed or meant for multiple pours.....basically as mentioned...a single shot, as I don't have much sterling to pour (just the 1 spoon melted along with the button). I realized it would catch fire when poured, but I just "sooted" it to be on the safe side to make a decent looking bar. I really don't plan on selling any sterling silver until I amass a large amount,,,which I will then melt into one large bar,,,and have assayed if I decide to sell. It's more of a hobby than an effort to make money.

This is my blast furnace I built for melting larger amounts. It can run on a variety of different fuels (wood,charcoal,motor oil,veggie oil, and propane).

 

[goldsilverpro]

Very interesting. I can see now how it might just work and I am impressed. I agree, though - A solid piece of hardwood would likely be the best. The lamination layers would possibly react differently and affect the casting. I would think a hardwood with a tight uniform grain would be best. Basswood? Mahogany? Maple? What did the ancients use?

 

[boochieboy]

Very interesting. I can see now how it might just work and I am impressed. I agree, though - A solid piece of hardwood would likely be the best. The lamination layers would possibly react differently and affect the casting. I would think a hardwood with a tight uniform grain would be best. Basswood? Mahogany? Maple? What did the ancients use?

I will post a picture or maybe even a video when I do it.
I'm sure that no one single hardwood would be absolutely best in all situations. Whatever the earlier civilizations used would probably have been based on their region, and available species....so it would differ from one location to the other. I have been a carpenter for over 10 years now, and I would say that any hardwood with a tight grain and small pores (as you suggested) would work fine. Cherry may be a good example.

 

[qst42know]

I don't know which wood may have been used first but charcoal blocks are still found in jewelers catalogs. The modern stuff being chemically impregnated and pricey for a carbonized litle piece of wood.

http://www.fdjtool.com/category.aspx?categoryID=1794

 

[goldsilverpro]

Very interesting. I can see now how it might just work and I am impressed. I agree, though - A solid piece of hardwood would likely be the best. The lamination layers would possibly react differently and affect the casting. I would think a hardwood with a tight uniform grain would be best. Basswood? Mahogany? Maple? What did the ancients use?

I will post a picture or maybe even a video when I do it.
I'm sure that no one single hardwood would be absolutely best in all situations. Whatever the earlier civilizations used would probably have been based on their region, and available species....so it would differ from one location to the other. I have been a carpenter for over 10 years now, and I would say that any hardwood with a tight grain and small pores (as you suggested) would work fine. Cherry may be a good example.

I think you're right. Cherry may work. I don't think oak would be worth a damn. Too many pores.

Good to meet a fellow woodworker/carpenter. My hobby, for 45 years, has been making carved, gold-leafed signs, mainly from genuine mahogany. Here's a thread where my ego got the best of me.

http://www.goldrefiningforum.com/phpBB3/viewtopic.php?f=67&t=6955&p=62571&hilit=signs#p62571

 

[boochieboy]

Very interesting. I can see now how it might just work and I am impressed. I agree, though - A solid piece of hardwood would likely be the best. The lamination layers would possibly react differently and affect the casting. I would think a hardwood with a tight uniform grain would be best. Basswood? Mahogany? Maple? What did the ancients use?

I will post a picture or maybe even a video when I do it.
I'm sure that no one single hardwood would be absolutely best in all situations. Whatever the earlier civilizations used would probably have been based on their region, and available species....so it would differ from one location to the other. I have been a carpenter for over 10 years now, and I would say that any hardwood with a tight grain and small pores (as you suggested) would work fine. Cherry may be a good example.

I think you're right. Cherry may work. I don't think oak would be worth a damn. Too many pores.

Good to meet a fellow woodworker/carpenter. My hobby, for 45 years, has been making carved, gold-leafed signs, mainly from genuine mahogany. Here's a thread where my ego got the best of me.

http://www.goldrefiningforum.com/phpBB3/viewtopic.php?f=67&t=6955&p=62571&hilit=signs#p62571

Yeah, I would be afraid the molten metal would find it's way into the pores and solidify,,,,locking the ingot in the mold, or creating a less than pretty finish on the ingot. If anyone else uses a wood mold it may be better to skip the glue unlike what I did, and just screw or nail the mold together. I think the glue will hold up just fine for the 3-4 seconds until the metal solidifies, but you never know. Like i said before,,I'll try and make a video when I pour it.

I'm more of a cabinetmaker/furniture maker at heart, but hey...a woodworker is a woodworker! I don't think I'd have the patience for hand carving, but if the need arose, I'm sure I would give it a go. I do agree with you about not liking woodworking as a business though. If I'm building/creating something I take my time, and make sure it's done the correct way. I worked at a cabinetmaking shop for 10 months, and then quit. I couldn't stand building under ridiculous production times, and slapping things together like garbage just to get the job done, like they wanted. I just couldn't put my name on a cabinet that would fall apart in a few years.

 

[goldenchild]

I guess it would depend on the wood used and how intense the flame is. Check this video out

http://www.youtube.com/watch?v=PgmFRzT96-0

Its a HHO torch which can be extremely hot but the flame is small cutting down on the damage done to the wood.

I'm sure you guys have seen this one too. I think it actually may be a forum member. The melting starts at 1:52

http://www.youtube.com/watch?v=kq1W-QdMsWQ

 

[qst42know]

Once the wood carbonizes it won't trap anything.

Wood shrinks so much when burnt you could probably pour into an undercut cavity and have no trouble.

Hard and dense like hickory or elm, or soft and porous like willow or cotton wood?

As a mold perhaps any?

Was the board you used as a melting dish a standard 2x4?

 

[boochieboy]

Once the wood carbonizes it won't trap anything.

Wood shrinks so much when burnt you could probably pour into an undercut cavity and have no trouble.

Hard and dense like hickory or elm, or soft and porous like willow or cotton wood?

As a mold perhaps any?

Was the board you used as a melting dish a standard 2x4?

I'm not sure if your comment is directed towards me, but that wasn't my youtube video. I have however used wood as a melting dish like in that video. My silver button (pictured above) was melted on a block of pine.

 

[boochieboy]

Hey everyone,,,here's my video using the wooden ingot mold. This is my very first actual pour....EVER! Let me know what ya think. Actual pouting starts at 1:15. http://www.youtube.com/watch?v=i341kVN5GVI

 

[qst42know]

Nice pour. 8)

That makes a reasonably clean ingot. It looks like you may get another pour in the same cavity though it may be a bit larger.

 

[boochieboy]

Nice pour. 8)

That makes a reasonably clean ingot. It looks like you may get another pour in the same cavity though it may be a bit larger.

Thank you. You could get another pour out of it,,,,,just wouldn't be as pretty as the first.

 

[goldenchild]

I can almost guarantee you could get more than 1 more pour out of that mold.

 

[mikeTV]

Hello, first post! I am trying to do this myself using all the same materials with the exception of a graphite mold. Unfortunately my results have not been as nice as boochieboy's. The ingot is "layered". I keep the flame on the silver during the pour and make sure the mold is hot. I have tried MAPP gas and different amounts of borax with the same results. I am doing this outside in the winter, could this have a effect on it? I have included a few pic's, they will probably be able to describe the problem better then my words. Any constructive criticism is more than welcome.
Thanks
Jeremy

 

[goldenchild]

Looks like there is copper and or gold in your ingot. How pure was your silver? What kind of torch were you using? Was your crucible very dirty?