casting sterling silver bars

[bigdyo90]

any thoughts on the matter? I have some sterling jewelry(NOT FOR SALE) that I want to make bars out of.

I cant do chemical proccesses to further refine the silver, the only place i could is out doors and I have cats, who I would'nt risk for all the gold Harold has seen. :mrgreen:

but anyways, are there any possible problems you gentlemen think will arise from the smelting/casting?

 

[philddreamer]

Bigdyo, do you have the proper set up for melting your sterling?
Do you have the proper safety equipment for the fumes? http://goldrefiningforum.com/phpBB3/viewtopic.php?f=47&t=14983#p151304
How much material you plan to melt? Are you using a melting dish or a crucible? What type of torch do you have? What type of mold?

http://goldrefiningforum.com/phpBB3/viewtopic.php?f=61&t=15134#p153088

Take care & be safe!
Phil

 

[bigdyo90]

I plan on doing it out doors with a small circulating fan 18" away blowing at the top of the kiln which is firebricks and charcoal (poor man's) I plan on using a propyplene torch with a swirl tip to expediate the melting after the coal has gone for a while, and also to heat up the fire bricks. I will be doing it in this order planned and PLEASE correct me if I need to be or if you have a ny tips:

This is after it is assembled

1 Heat bricks and crucible

2 Light charcoal ( lighter fluid on the outer coals?)

3 quickly turn on fan ( 8" but i have bigger if needed.....)

4 let burn for awhile ( 30-45

5 after waiting impatiently far behind the fan go assess the silver in a dust mask(the good ones, not the little fiber paper or whatever)

6 torch crucible till sterling is molten

I am not going to attempt this until i have more clarity on the matter (duh) 8)

Thanks for the concern healthwise, by the way

 

[bigdyo90]

I want to clarify these steps before going any further in my plans

I have all graphite crucibles/molds and will only use tested sterling plus .999 shot to get .925 +


sorry i was gonna put that in my last post.

 

[element47.5]

I guess I have seen YouTube videos of melting a couple of oz silver with a MAPP torch but at the same time, there is something self-defeating about the idea of having to hold a torch on a melt for 20, 30 minutes to have it melt. I suppose you eventually get there, but that very circumstance, to me, is indicative of just not having enough heat. It doesn't miss by much, but it DOES miss. I know that for me, having to hold to hold a torch on something that long, I would lose patience and act in haste in some form or fashion. That might be different for you, I can only speak for myself. I am not saying what you propose is impossible. I won't even mention the fuel costs of MAPP on a 20+ minute burn for a small, 1-2-3 oz melt, which I think is going to be your max capacity. And obviously, the longer you hold your melt at high temps, the easier it is to become contaminated.

I also think this is a path that leads to less-than-satisfactory results because you do not have good control over the mixing characteristics of the flame. Eg; you can't produce a reducing, oxy-starved flame. You can't soot the mold, though maybe you could do this by blocking the intake vents with a sliding metal sleeve or even your fingers. I am absolutely sure there is someone, somewhere, who can do this, but I see no good answer to the tendency of silver to spit crossing its plastic zone.

I hate to be discouraging, but color me pessimistic.

 

[bigdyo90]

ok so whats the benefits of oxy acetylene

I tried to search for a guide on using it but maybe i did it wrong (tons ofresults,no luck)

did learn a bit but wanted to ask the question outright :lol: :

best way to melt .925 and silver shot?

 

[element47.5]

1: heat for 2-3 minutes instead of 20
2: ability to easily soot a mold for easy release and superior finish
3: ability to feather the flame to "ripple" the top surface which seems like it floats flux off to the side, produces a superior top finish, reducing finish/polish time
4: cheaper than MAPP per unit of time torch is in use, which is likely to be reduced by 80+%
[this is assuming you get your MAPP in a Bernz-o-matic sized cylinder and your acet or your propane in a much larger cylinder. You can get MAPP in large industrial sized cylinders, but it is still lots more expensive than acet or propane]
5: MUCH larger ingot capacity
6: better selection of torch tips
7: torch (with tip change and unfortunately, now, with regulator fitting change) can also be used with oxy/propane = even cheaper than acet
8: no need to become involved with your firebrick "enclosure"

can weld or cut steel with it

those are what come to mind. The key point is: oxygen; the ability to add it for super heat, and the ability to to starve the flame to reducing flame by choking it off.

 

[bigdyo90]

valid points

 

[publius]

If you insist on using wood for your molds, back at 375 to 400 degrees (f) for 2-4 hours depending on the thickness. That will drive most moisture in the wood. plan to used these as soon as they come out of the oven!