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Bronze casting


Daniel J. Luevano
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I tried making a crucible by hand from aluminum oxide, iron dust, shifted earth and wood ash, it was working but as I heated it to harden it, it just fell apart. I'm trying to make aluminum bronze, I know that copper and aluminum melt at lower temps than steel but I don't know if it could withstand the heat needed to get through the vessel and melt the copper. Help please, I don't want to have to spend much either.

"Behold, I have created the smith who blows the fire of coals and produces a weapon for its purpose. I have also created the ravager to destroy;"-Isaiah 54:16

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What is your plan for the Al/bronze?

 

I have made it a few times. It is, in my opinion the toughest to work with.

 

While it can be very gold like and pretty. Low zinc brass is, imho, just as gold like, and MUCH easier to work with.

Get yourself a nice Graphite crucible. Or find some clay to add to your formula. You will need some kind of clay, that can withstand some good heat as a base.

There are a few good crucible recipies on this and other sites, but if you don't have the material, and a good way to fire them, you may as well buy one. Even a cheep graphite crucible can be used many many times, if your just melting copper based products.

 

Mark

Mark Green

 

I have a way? Is that better then a plan?

(cptn. Mal)

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Daniel, I'm sorry to hear you've been having problems.

 

If your earth had no clay in it, it will fall apart as soon as the organic matter burns off. Hand dug clay is usually too naturally fluxed up to hold up to much heat, anyway, unless you're in a place with an open seam of primary clay (ball clay or kaolin--Georgia, Kentucky, and Tennessee for instance). I would keep the wood ash out of your mix, as well--it only lowers melting temps, especially if unwashed.

 

What were you using to fire? Thermal shock and moisture are treacherous enemies to a firing piece.

 

The cheapest option really is a commercial crucible, I think. The look expensive, but firing anything is expensive, then you've got materials, time, and have to account for failures (ceramics are ALL about failure). Plus, you won't have the quality controls of a commercial crucible. I don't know about you, but I'd want to be sure my yellow-hot vessel full of liquid pain and death doesn't crack, burst, or explode while I'm fiddling with it.

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Go to come of your casting supply places that sell online to people who do small scale casting and look for a deoxidizer for casting bronze. That way you can do a simpler tin bronze and not end up with a lot of bubbles in it. Some may also have links for making some of the other things that you will need for casting or other supplies. Just remember that some things are easier and cheaper to buy than to make for yourself.

 

Doug

HELP...I'm a twenty year old trapped in the body of an old man!!!

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What is your plan for the Al/bronze?

 

Well I have read that al/bronze is one of the stronger bronzes, so I was hoping ,once I had a good crucible, to cast guards and pommels out of it. That and I have some aluminum laying around.

 

If your earth had no clay in it, it will fall apart as soon as the organic matter burns off. Hand dug clay is usually too naturally fluxed up to hold up to much heat, anyway, unless you're in a place with an open seam of primary clay (ball clay or kaolin--Georgia, Kentucky, and Tennessee for instance). I would keep the wood ash out of your mix, as well--it only lowers melting temps, especially if unwashed.

 

Well I live in Colorado, but I don't believe the light brown soil in my yard has much clay in it. I will remember to keep the ash out as well.

"Behold, I have created the smith who blows the fire of coals and produces a weapon for its purpose. I have also created the ravager to destroy;"-Isaiah 54:16

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Daniel,

 

Al/bronze is pretty strong. But, at least in my experience, it is very hard to pore into good molds. It seems very brittle, compared to some others. Tin bronze, is just about as strong, and much easier to work with.

I like low zinc (like 12-15%) brass as well.

If your casting guards, and pommels, these would be quite a bit easier to start with.

Melting any kind of copper based alloy, you will need to be sure you keep the oxygen out. This can be done with fluxes, or just simply keep a half inch of small charcoal chunks on top of your melt. This seems to work just fine most of the time.

Others may chime in on the Al/bronze, but in my experience, just about all the other options are better.

 

Mark

Mark Green

 

I have a way? Is that better then a plan?

(cptn. Mal)

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it might be easier to use tin (German: Zinn) to make a good workable bronze,

use pure copper and 10 to 15 % tin,

when you use zinc, like Mark said, you will get brass, but you will have to be very carefull about heating zinc, because of the fumes that are hazardous,

we have some very good smithing bronce here in Germany with Si in it with some very good features for smithing,

for casting bronze you may use up to 22% of tin,

when you mix the copper with lead (1-8%) and 5-11% tin (and eventually some zink (1%)you get "Rotguss" or „leaded red brass“ which will be easier to pour or cast

 

and pls, buy yourself a crucible (graphite) good tongs and very good gloves

that will keep you from getting harmed

 

 

my 5 ct with the help of "uncle wiki"

Jokke

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