Melting bronze in an Evenheat?

T

Tenebr0s

Joined
Jun 3, 2012
Messages
397
I'm interested in doing a small amount of bronze casting, and was wondering whether anyone here has used an electric kiln for this? I'm a little concerned about the oxidizing atmosphere.
 
How much are you wanting to melt? Most bronze melts around 1850°f but you don’t cast at that temp. Normal casting temp is around 2000° or there abouts. Personally I would not melt bronze in my heat treat oven as I can not afford to mess it up and I have forges for that kind of work. I know people do it in electric ovens and most precious metals are melted Thad way. Oxidizing can be an issue and so can desolved gasses. Gas in the air can become desolved in your alloy making a kinda carbonated liquid like a soda. As the aloy cools in the mold the gas is released and bubbles. This is especially a problem with copper and why getting solid castings with it is difacult. I just use a little pinch of flux (borax) with the aloy. This shealds the top of the liquid from the atmosphere.
 
+1 on that.

A kiln can melt it, but you will probably want to use flux to deal with Oxidation and any Borax or similar that gets on the IFBs will eat them.

Do not ask me how I know this.

I’d build something I didn’t mind damaging for the task.
 
Thanks for the replies!

I’ll build something dedicated for casting then. Not looking to melt a lot - probably half a pound max at a time.
 
You could easily make a knock down melting setup with firebricks and a blown burner. It would basically be a vertical Tai Goo weed burner setup. A piece of 1" IBF could be the top.
 
Hell, I would just find a 10" ID pipe drop from your local steel yard. Weld on a base, drill a hole in the side (or plasma if you got it), and weld on a short section of tapped pipe to hold your burner. Dead simple top is the same plate you used for your base with a piece of 2-3" x 1/8" rectangle welded around the perimeter. Tack some little Vs of steel over the inside and pour in a castable (it you want more durability, spoke the center of the top with thin rebar). Weld a U on the top to lift off the body. Simple. Maybe $50 if you can find the drops.
 
Yep, that is what I meant by "simple vertical melting forge". It can be made from scrap materials if you have some scrounging ability. A wrap of uncoated wool on the inside would work for something this light duty. If the OP wasn't a but far to drive, I could give him all the needed material.

I am in the process of welding up a nearly identical little forge that will hold a small salt pot for bluing. All I would need to do was pull the salt tube and set in a graphite crucible to melt bronze in it ( which I have considered).
 
I may just build from scratch, but if this kind of grill would work, $25 seems like a pretty good deal.

One way or another, though, solid fuel would be a lot easier for me, since I’ve already got it. Any reason something like coke, instead of propane, wouldn’t be a good idea? Other than the need to add more of it, as it burns.
 
It would be harder to make a solid fuel furnace, if you want it to last. Problem is that you can't just lay your crucible in a bed of coals and it not break. So you would need to do a firebox with a furnace floor.

If I was gonna have to avoid propane, I would do a blown oil furnace. Basically the same design as the propane furnace, just sub an oil burner.
 
That grill won't work for melting bronze to cast.

Solid fuel would be a big problem, too.
I think an oil burner would be far too large for such a small furnace. Just make it run on propane and it will be quick and easy.

One thing people don't consider when running an oil burner is that unless it is running properly and blown by a big blower - like it is in a boiler or home oil fired heater - it will give off some really bad by-products. Dioxin is a really bad one. Most forges are far too small for a proper oil fired burner.
 
Propane tanks are honestly a bit of a hassle to get over here. In the States, I just take my tank down to the hardware store a refill it, but I have yet to see that in Japan.

At the risk of sounding overly contrarian, people have been melting bronze with solid fuel for thousands of years. So it obviously can be done. I understand crucible life will be shortened by solid fuel, but surely it can survive the occasional melt?

Just curious what are the potential setbacks with coke? The basic furnaces introduced here are for solid fuel, and don't have anything extra to protect the crucible: https://the-eye.eu/public/murdercube.com/Workshop/Metallurgy/Foundrywork for the Amateur.pdf
 
You will have to have a good airflow and seat the crucible in the fire. It certainly can be done. I was just saying it is a bit more than sticking it in a BBQ/Hibachi pot.

As you can see in the book, you will have to get a bunch of firebrick, sheet metal, a blower that you can control, etc. to make one. You said it would be for infrequent use, which was why I said it may not be cost efficient.

Now, if you want to build a deep coke/charcoal forge and do both forging and melting unit, that would be more cost effective.
 
They greatly discourage using any type of fire device that has a large flame or lots of gas fuel in Japan. Bulk tanks are available, but there are many restrictions on where you can use one. Depending on where you live, getting the tank may not be the issue …. running a forge may be the problem. I think this site will help you a bit:
https://www.ezbbq.com/lpgas/index.html
 
Thanks Stacy. I have a workshop in Kyoto where I run a forge, so no problem there. I just don't think my forge is a good size/setup for doing the melt in, which is why I'm looking to make something dedicated for casting. But yes - they ARE very nervous about fire, which is one of the reasons I don't want to go through the hassle of getting a propane tank. My landlord is ok with my current setup, but I don't want to push it.
 
You must log in or register to reply here.
Back
Top