Non-Chemical Pouring exactly 1 troy ounce at a time

[glorycloud]

Sad but true. E scrap takes a lot of labor to process and refine.
Luckily for some of us, we get the stuff for free as part of what
we do. For me, that is selling computer equipment on the for profit
side and giving away PC's on the 501C3 side of what I do. Both sides
feed the escrap pile. My customers are grateful to have me haul
off there "junque" because they trust that I will deal responsibly
with the material for them. I get donated equipment as well and
what I can't use internally, I break down for parts or recycle.

All that means is that I get the material "for free", so to speak.
I invest my time and effort to pick off what I want from the
pile of escrap and sell the rest to the refiners for them to process.
So, for a little time invested, I get to dissolve some base metals
and get a few nice shiny gold buttons on occassion. 8)

This forum has provided so much information to someone like
me and I am grateful for what you all offer so freely - good practical
advice! Without that advice, I would be sending all my "golden goodies"
off to ebay or the refiners for sale and where is the fun in that? :lol:

Having said all that, if I weren't getting the escrap for free it would
surely be difficult to justify the time, effort and materials required
to tinker around with this stuff. I would wager that many who find
this forum useful have seen the gold glittering on a scrapped out
computer and have said gee, I might not quit my full time job to do
this but I will at least safely give it a try and see what happens.
After seeing what it takes to get .75 grams of gold they go away.
Lesson learned for them but hey maybe they can take something
positive from it like I have: It's a hobby and I have fun doing it. 8)

 

[Oz]

At this state of the economy, I would define "high grade" as anything that was worth at least $200-$300 per pound in gold content

Even when free I only run material that has been high graded first.

This is one of the reasons I feel silver is under priced, it is thrown away due to the cost of recycling unlike gold. Silver spot prices will ultimately be pushed up at least to the point that it is economical to recover it from e-scrap in my opinion. For some time more silver has gone to the landfill than has been mined in that same year. That will end.

 

[Anonymous]

Just a thought Why pour at all why not just use a porceline mold to cast cheap ingots from clay then add gold to the cheap ingots and allow them to fire in a kiln. at the end of the process just break off the clay?

 

[leavemealone]

Just a thought Why pour at all

I recommend you spend an abundance of time researching what we do here,and the different procedures before making a suggestion like this.

why not just use a porceline mold to cast cheap ingots from clay then add gold to the cheap ingots and allow them to fire in a kiln. at the end of the process just break off the clay?

Because that is a form of lost casting(similar to lost wax casting),that will never work for what he was trying to accomplish.You would be doing multiple steps,when 1 step would be sufficient.....thats why.

 

[19Smitty77]

On the very first page, someone mentioned that alterering an ingot by filing on it voids the markings. Totally makes sense. When and if I reach the point of making a freshly poured ingot, My plan was to stamp the weight and kt using something like a leather stamping kit. Is this a sound plan? Pros? Cons?

 

[Harold_V]

On the very first page, someone mentioned that alterering an ingot by filing on it voids the markings. Totally makes sense. When and if I reach the point of making a freshly poured ingot, My plan was to stamp the weight and kt using something like a leather stamping kit. Is this a sound plan? Pros? Cons?

That may work, but you can purchase inexpensive stamps intended for makring metals by paying a visit to a Harbor Freight Store.

The real problem you'll face when pouring ingots is determining a realistic weight, as well as the purity of your product. You should be able to weigh gold to no less than four places after the period.

You may wish to mark in the metric system, but don't lose sight of the fact that gold is sold by the troy ounce. You would need to get accustomed to using the grain scale when weighing by that method, which is also commonly used in hand loading cartridges for guns. It's very easy to learn.

Do remember---when working with the troy system, an ounce is larger than an avoirdupois ounce (troy 480 grains, Av 437.5 grains) and a troy pound is smaller than an avoirdupois pound (12 troy ounces = 1 troy pound ---5,760 grains) versus 16 av. ounces = 1 av. pound--- 7,000 grains). In troy, there is common discussion of pennyweights (dwt). A dwt weighs 24 grains, and there's 20 dwt per troy ounce.

Harold

 

[19Smitty77]

Thanks Harold!

I'll check into harbor freight like you said. I'm still along way off as I am still gathering jewelry for my first inquartation. I've gotten really excited about this especially after reading the information on this forum!

EDIT: Yep I know a Troy ounce is roughly 31.1 grams. I'm not too worried about 4 decimal places at this point because I'm looking at it from a novice hobbyists point of view. I'm sure though, that once I get into it the drive for perfection will set in LoL

 

[goldsilverpro]

I'm not too worried about 4 decimal places at this point because I'm looking at it from a novice hobbyists point of view. I'm sure though, that once I get into it the drive for perfection will set in

The better reloading scales that Harold mentioned weight down to 0.1 grains. That is about 0.0002 troy ounces. If you're using any other type of lesser scale, make sure the the weight that is stamped on the bar is less than the weight determined by the scale you're using. If you're using a 1 or 2 decimal point gram scale, I would reduce the last digit by at least one number. You never want to stamp more than the true weight. Just remember that, no matter what scale you use, the last digit is always questionable, at least by one number.

 

[19Smitty77]

If you're using a 1 or 2 decimal point gram scale, I would reduce the last digit by at least one number. You never want to stamp more than the true weight. Just remember that, no matter what scale you use, the last digit is always questionable, at least by one number.

Oh wow, good point, I never considered breaking the law unintentionally. That's an entirely possible scenario.

 

[Harold_V]

If you're using a 1 or 2 decimal point gram scale, I would reduce the last digit by at least one number. You never want to stamp more than the true weight. Just remember that, no matter what scale you use, the last digit is always questionable, at least by one number.

Oh wow, good point, I never considered breaking the law unintentionally. That's an entirely possible scenario.

It's not so much breaking the law as it is screwing up your credibility. No one will complain if you give them a tenth of a grain too much, but short them the same amount and you're labeled a crook.

When I refined, virtually 100% of the gold I produced was returned to the customer, less my percentage. When I'd mark the package, I always rounded down, and marked to only two places. That way, when they weighed the gold, it always weighed more than the package mark. You'd be surprised how many guys would call me to tell me I had given them too much gold. They check, and they expect fair treatment.

When a call came, I'd just chuckle and tell them that what they got was rightfully theirs, and to enjoy the spoils.

Credibility in refining is everything---assuming you expect to build a viable business.

Harold

 

[joem]

A grass roots back yard gold person might use a metal scale, zero out the mold and pour until 1 oz is reached.
just my thought
joe

 

[jimdoc]

The gold cools too quickly to make that work,
without luck on your side.It would be harder
than it seems.

Jim

 

[Anonymous]

A grass roots back yard gold person might use a metal scale, zero out the mold and pour until 1 oz is reached.
just my thought

Thats why they would be called a "grass roots back yard gold person"

The gold cools too quickly to make that work

The gold "cooling",is not the issue.The issue is getting an accurate weight,which can not be accomplishd with a traditional scale,and certainly not by tearing off the weight of a mold and pouring.A single drop of liquid gold could weigh as much as a half of a gram.When you are trying to weigh out to the 4th decimal place this cannot be accomplished
Countless accurate ideas have already been suggested on this matter

 

[joem]

I like giving a bit more. It keeps you credible. and why worry about the weight any buyer will weight it anyway and you should be paid by the price per weight.
joe

 

[MargueriteMingorance]

I am really new to this, and still learning the termanology.

You have far more than terminology to learn. You have yet to discover that the suggestions you provided

My idea is when you get ready to melt the gold, add a little extra to compinsate for the amount that is left in the crucible after you finish pouring so that you make sure that you have enough. Also, you could take your empty ingots, place them on a scale, and zero the scale with the ingots on it. Then pour the gold into the ingot until the scale reads 1oz. If you have 4 spaces on one ingot, then pour the gold in the first space until the scale reads 1oz, and then pour the gold into the second space until the scale reads 2oz(1oz in the first space and pouring the second ounce) and so on.

are worthless.

Yes, they make sense on paper, but in practice they do not, nor will they ever---not pouring by hand. If you are familiar with a grain of gold, and how small it is, and consider a grain equates to 1/480th of a troy ounce, and an ingot is weighed to 4 places, a tenth of a grain effects the weight of an ingot by .0010 ounce. You simply can not control the pour to that degree of precision, nor will gold cooperate with tipping miniscule amounts.

I'm not trying to be rude----I'm just trying to have you understand that you are dealing with infinitely small units, all of which are very important in the way of credibility. Ingots must weigh what they are marked, and establishing a desired weight is likely to be beyond your ability. You pretty much have to settle for random ingots unless you pour them heavy, then adjust their weight before die striking. That would create a uniform surface. The alternative is to roll gold to a specific thickness, punch a planchet, which would be adjusted for weight, then die struck. You would fail miserably at pouring ingots of a specific weight, although you will hit the occasional one. It happened for me, but rarely. It was not predictable in spite of considerable effort.

Harold

How about...

Assuming a graphite mold, using an electric furnace and an inert atmosphere...

Weigh out 1 ounce exactly of shotted gold, pour it in the mold (it's okay if it heaps up some) then pop the whole thing into the furnace and melt it.

 

[lazersteve]

Check this thread:

Can you melt in the mold?

Steve

 

[MargueriteMingorance]

I should have figured it could not be that easy. I was basing the possible success on the fact that the Kerr Electro-melt furnaces and the large vacuum furnaces sold by Rio Grande both use graphite crucibles which are quite durable for that use.

They may present the appearance of being durable, but they aren't. Because the temperatures involved are well above the combustion point of carbon, they burn away rapidly, primarily from the shoulder upwards. That's one of the reasons they provide a cover, which limits the exposure to oxygen, but not enough to be totally effective.

When the furnace is up to heat, even for melting silver, there is a visible flame coming off the graphite around the rim. Failure of the crucible body isn't the problem, the problem is the top burns away such that the crucible is no longer supported by the rim, and there is no pouring spout to allow the crucible to be emptied in a safe fashion, where the discharge is desired.

Okie doke. So, need to use something other than graphite, or metal, for the mold, right? What about fused quartz? That's like glass, right? It should give a very smooth finish.

Since you're reheating the gold in the mold, you can bring the temp up slowly, and then let it cool slowly. This would avoid thermal shocks. After all, that is how glass is anealed. Since the gold will shrink on cooling, it should come out of the mold fine. A mold made of SiO2 won't contaminate the gold, will it?

For silver, could you coat the mold with a dusting of graphite? It would burn away as CO2, absorbing any oxygen. I would suggest oil, but it contains impurities, like sulphur and chlorine, and maybe trace metals.

The melting point of pure SiO2 is 1650C. Melting point of gold is 1065C, silver is 962C.

 

[MargueriteMingorance]

If you're using a 1 or 2 decimal point gram scale, I would reduce the last digit by at least one number. You never want to stamp more than the true weight. Just remember that, no matter what scale you use, the last digit is always questionable, at least by one number.

Oh wow, good point, I never considered breaking the law unintentionally. That's an entirely possible scenario.

It's not so much breaking the law as it is screwing up your credibility. No one will complain if you give them a tenth of a grain too much, but short them the same amount and you're labeled a crook.

Well, actually, technically, it's fraud. It is breaking the law, at least if you represent that the bar actually weighs what it says it weighs.

 

[lazersteve]

...
Okie doke. So, need to use something other than graphite, or metal, for the mold, right? What about fused quartz? That's like glass, right? It should give a very smooth finish.

Since you're reheating the gold in the mold, you can bring the temp up slowly, and then let it cool slowly. This would avoid thermal shocks. After all, that is how glass is anealed. Since the gold will shrink on cooling, it should come out of the mold fine. A mold made of SiO2 won't contaminate the gold, will it?

For silver, could you coat the mold with a dusting of graphite? It would burn away as CO2, absorbing any oxygen. I would suggest oil, but it contains impurities, like sulphur and chlorine, and maybe trace metals.

The melting point of pure SiO2 is 1650C. Melting point of gold is 1065C, silver is 962C.

Not a terrible idea, but a few points:

1. Quartz will tend to devitrify and decay at elevated temperatures after repeated use.

2. Machined fused quartz is very expensive.

3. Fused Quartz is very brittle and is easily broken if mishandled or dropped. The good thing about quartz is it can go from hot to cold relatively quickly and not shatter like Pyrex or lesser glass.

4. Fused quartz requires special handling considerations to maintain it's continued integrity.

Here's a usage guide for fused quartz:

Fused Quartz Usage Guide

I can't help but think you would quickly ruin your expensive quartz mold with skin oil, furnace trash, and other contaminates found in the metal and melting process.

If you could over come and/or address the points above, I think you may be on to something, but I've never tried it my self. I own several pieces of quartz ware and they require special attention unless you have deep pocket for buying new quartz equipment.

The expense of quartz fabrication will typically equal or exceed the already high cost of the raw materials to make the item out of quartz, in your case bar molds. If you have a few extra hundred bucks laying around and want to give it is shot, I for one would like to see the results.

Steve

 

[T3sl4]

They may present the appearance of being durable, but they aren't. Because the temperatures involved are well above the combustion point of carbon, they burn away rapidly, primarily from the shoulder upwards. That's one of the reasons they provide a cover, which limits the exposure to oxygen, but not enough to be totally effective.

When the furnace is up to heat, even for melting silver, there is a visible flame coming off the graphite around the rim. Failure of the crucible body isn't the problem, the problem is the top burns away such that the crucible is no longer supported by the rim, and there is no pouring spout to allow the crucible to be emptied in a safe fashion, where the discharge is desired.

Video footage:
[youtube]http://www.youtube.com/watch?v=-_Dj_DoIHhs[/youtube]

At the surface, carbon monoxide forms. When it reaches cooler air, it burns with a weak blue flame. The erosion rate is pretty serious when the crucible is packed with nice and porous kaowool -- your average crucible may only last an hour, total!

Tim