Any good strategy for making 1oz ingots?

[ssharktu17]

Say you wanted to make 100 exactly 1oz ingots at once how would you do it? Most videos I see are just people guessing on their pours and coming out with 100 different sized ingots.

 

[Elemental]

The best advice I would have for any ingot, is to just pre-weigh your grains/shot and then pour just that. 1 troy oz. bars are small and finicky though. But if you weight out 1 troy oz. and you pour it all (I usually add a gram or two extra due to melt loss), then you have a 1 troy oz. bar. Be mindful of oxygen absorbance, molten silver can absorb 20x it's volume in oxygen and when it off-gasses when the silver freezes, it leave the silver and makes it look like crap. Best to use a reducing flame, if you're using a oxy-(anything) torch.

A mint would pour them into a strip, use a rolling-mill to get down to an exact thickness (while doing a lot of annealing between rolls, and then using a punching machine to cut blanks. Of course these are no longer really ingots, but blanks. This is how they make coins, although the blanks don't have to be round.

 

[ssharktu17]

The best advice I would have for any ingot, is to just pre-weigh your grains/shot and then pour just that. 1 troy oz. bars are small and finicky though. But if you weight out 1 troy oz. and you pour it all (I usually add a gram or two extra due to melt loss), then you have a 1 troy oz. bar. Be mindful of oxygen absorbance, molten silver can absorb 20x it's volume in oxygen and when it off-gasses when the silver freezes, it leave the silver and makes it look like crap. Best to use a reducing flame, if you're using a oxy-(anything) torch.

A mint would pour them into a strip, use a rolling-mill to get down to an exact thickness (while doing a lot of annealing between rolls, and then using a punching machine to cut blanks. Of course these are no longer really ingots, but blanks. This is how they make coins, although the blanks don't have to be round.

Seems incredibly tedious. What about just melting the shot in the graphite mold? like baking cookies lol.

 

[Elemental]

Your mold won't last too long, I imagine. Let me pull some videos of people pouring ingots. Below are a few videos you can find on YouTube in referencing to doing exactly what you're talking about. Streetips on you-tube has plenty of good tutorials on pouring both silver and gold as well.

Join me as I LIVE pour & Stamp 1 oz Silver Forum Bars!


Making some Hand Poured Silver bars!


STREETIPS Videos(You'll need to search for his silver videos):
https://www.youtube.com/channel/UCiXLCOsqf4rYYMSU6izlJSA

 

[Elemental]

As an aside, the perfectionist in me wants to pour silver ingot bars and then use a milling machine (like a Sherline, Sherline Vertical Milling Machines – Sherline Products), to mill them down to exact tolerances while having a logo/size/material embossed on the silver that isn't cut away. Needless to say, this is likely both silly and unnecessary. But I think it's a cool idea. It would give me exact masses on each bar, and they would all be identical.

 

[ssharktu17]

As an aside, the perfectionist in me wants to pour silver ingot bars and then use a milling machine (like a Sherline, Sherline Vertical Milling Machines – Sherline Products), to mill them down to exact tolerances while having a logo/size/material embossed on the silver that isn't cut away. Needless to say, this is likely both silly and unnecessary. But I think it's a cool idea. It would give me exact masses on each bar, and they would all be identical.

That would be cool but impractical on any scale. Ya I’ve seen those videos they are just doing random weight pours.

 

[goldandsilver123]

You make a big bar, 500g ~ 1kg, roll it to a specific thickness, measured with a micrometer, then stamp out rounds, squares, rectangles, etc..

This way the stamped piece will have the correct weight.

Then you stamp your logo, you can see many videos on youtube, just search for coin minting

Edit: Just read that Elemental posted the exact same thing...

 

[Elemental]

Seems incredibly tedious. What about just melting the shot in the graphite mold? like baking cookies lol.

It doesn't actually take that long, I was able to pour twelve 250g bars in short order. The silver shot was weighed out into glass beakers then one bar was poured, the beaker was used to put the next batch into the furnace crucible. Set a clock for 15 minutes to allow the silver shot to melt, pour, repeat. Managed to pour them all in a few hours.

I also poured these to make anode bars and to practice pouring (a skill I have a lot of work to do to get better at, so practice makes perfect) for my silver cell.

 

[ssharktu17]

You make a big

It doesn't actually take that long, I was able to pour twelve 250g bars in short order. The silver shot was weighed out into glass beakers then one bar was poured, the beaker was used to put the next batch into the furnace crucible. Set a clock for 15 minutes to allow the silver shot to melt, pour, repeat. Managed to pour them all in a few hours.

I also poured these to make anode bars and to practice pouring (a skill I have a lot of work to do to get better at, so practice makes perfect) for my silver cell.

12 isn’t bad but say I wanted to melt a 1 thousand and bar and pour 1000 1oz ingots.

 

[Elemental]

Well, my first question would be, why not pour one hundred 10oz ingots or ten 100oz ingots? As these are more manageable to pour with your amount of volume. Although, I'm sure there is a reason for why you want to make such small ingots. What I want you to understand is that without a sizable investment in equipment, you really just have a lot of tedious work on your hands.

 

[nickvc]

From what I have seen with the big refiners the metal is melted into shot , dried fully , weighed exactly and put into I believe graphite molds and fed into a belt furnace,this is usually for larger bars as the cost of molds will be excessive for small bars, these as pointed out are usually stamped out as the finish proves.

 

[ssharktu17]

Well, my first question would be, why not pour one hundred 10oz ingots or ten 100oz ingots? As these are more manageable to pour with your amount of volume. Although, I'm sure there is a reason for why you want to make such small ingots. What I want you to understand is that without a sizable investment in equipment, you really just have a lot of tedious work on your hands.

1ozt are just more practical and have much higher premiums. If it came to it carrying around a 10ozt bar is not practical.

 

[nickvc]

1ozt are just more practical and have much higher premiums. If it came to it carrying around a 10ozt bar is not practical.

And the reason they carry a higher premium I pointed out above.

 

[speed]

Graphite molds in an argon purged furnace.

 

[ssharktu17]

From what I have seen with the big refiners the metal is melted into shot , dried fully , weighed exactly and put into I believe graphite molds and fed into a belt furnace,this is usually for larger bars as the cost of molds will be excessive for small bars, these as pointed out are usually stamped out as the finish proves.

Yup im thinking something like this. Im guessing a tray of 1ozt

 

[ssharktu17]

And the reason they carry a higher premium I pointed out above.

I believe they have a higher premium simply because they are more practical and also especially because the lower price point allows more competition from bidders.

 

[orvi]

I believe they have a higher premium simply because they are more practical and also especially because the lower price point allows more competition from bidders.

Also this could add up to the "why". But production cost is not negligeable. As it was said, bigger bars are made from uniform pre-made shot, which is carefully weighed and placed into graphite molds with lids, heated in some inert gas atmosphere furnance to prepare raw ingots, that are removed from the mold when cool, re-weighed, and stamped/"minted" to shape the metal nicely.
Most of the 1ozt or 10, 20, 50 g bars are produced just as coins are - from pure metal, sheet of perfect thickness is rolled, suitable dimension punchings are made and these are "minted" to form a bar shape. Easy, very quick, convenient and easily automated production on large scale.

 

[goldshark]

I hear what you are saying about 1 oz. rounds. They are more readily saleable for the refiner to sell 1 at a time if he needs the money, and does't want to sell 5 ozs. at a time. As stated, the premium comes from having to do more fabrication per oz.. I would suggest graphite cookie cutter molds. Weigh out shot, plus a little extra for loss. I don't know what the loss will be because of a few variables. Maybe someone else here can list a loss schedule.

 

[nickvc]

If done in an inert atmosphere and using shot not flake or powder there should be no loss as any volatile components would have already gone.