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High-Performance Blades Sharing ideas for getting the most out of our steel. |
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#1
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Refractory
So I'm going to cast me own bronze recipe and want to maybe make a makeshift foundry. It is a small amount, just enough for a pair of bolsters or a guard. The mold I'm ordering is 2-1/2"x7/8"x3/8" which is .82cubic inches and these are the crucibles I ordered:
http://www.ebay.com/itm/300622267872...84.m1439.l2649 I'm not sure if just my bernzomatic 8000 is enough using propane or mapp or if I should build a small foundry. I was thinking of using a paint can and casting some refractory cement in there with a torch portal and probably keeping it open. Using: http://www.google.com/products/catal...=0CGIQ8wIwATgK Also, how easy is it to machine graphite? Could I get something like: http://www.ebay.com/itm/Ingot-Mold-G...48355844332790 and open it up using a carbide cutting bit in a dremel? |
#2
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#3
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The melting temps of bronze will depend on the alloy. Aluminum bronze melts at 1190 (F) but most of the others start at 1500 - 1800. So MAPP or propylene might work for aluminum bronze but not for the others unless you can contain/insulate the heat and use a refractory to direct it back.
Graphite machines real easy but makes a huge mess. Save the powder for your files. Graphite also dulls HSS tooling so carbide is better to use. I have made several dozen different molds and specialty crucibles with it. And it is really useful with the induction forge since it produces heat along with the metal. |
#4
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The melting point for copper is listed at 1981 degrees F. so let's say that you need something that will run up to 2000 degrees to give you some time to pour if you are going to make your own bronze. I think that the crucibles are a little on the small side. I would go a couple of sizes larger or you will be sloshing your charge over the rim of the crucible even with small volumes.
The mold you have will produce a bar with a dimple in the center from where the bronze contracts. I would go for sand casting. You can get a sand casting kit that will have both parts of the mold and the green sand. You will have to supply something to ram the sand with and a parting agent, talcum powder will do fine. You will a block of wood or something to make a model of the size of bar that you want to work with or even a model of the bolsters or guard. You could consider making a refractory lined bucket for a forge with a single air pipe to the bottom of the fire box and use charcoal as fuel. A hair dryer should supply plenty of air. Doug __________________ If you're not making mistakes then you're not trying hard enough |
#5
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I got the crucibles in the mail today. Man they are smaller than I thought. But I'll play around with them before I get anything else. I've resolved to mix my own green sand recipe. I'm not casting figures so detail isnt an issue so I think my recipe will work for what I want.
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#6
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I do a limited amount of casting for guards and pommels. I use "white brass" from our local foundry supply and "silicon bronz" from our same foundry supply. I use a propane furnace that breaks down into three pieces: the top, the barrel or center section, and the bottom. The bottom section has a feed pipe where the propane is fed into the furnace from a tangential opening. Outside is a gas orphus and the gas valve screws into the propane tank. These little furnaces have an 8 inch inside diameter where the #5 size crucible sits. I use up to a # 8 size for some things.
I also use scrap brass and alloy with tin to get the product I want. The pouring temp' is about 1900 degrees, about 3 hundred degrees above the melting temp. I use "Petrabond" type sand mostly. I think I am telling you more than you want to know. If you want to have more information on sand prep or lost wax just ask. Good luck, Larry Peterson |
#7
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Thanks Larry,
I may be interested in lost wax casting in the future. Right now my problem is I can only find silicon and aluminum bronze but not tin bronze, so my main motivation is to make that alloy. I simply need the sand to give me some sort of bar even if I have to grind a little on the outside. |
#8
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That's the problem with wanting to use a simple tin bronze, you usually have to end up making your own. Except for statuary, it's not used much commercially from what I understand. I'm thinking about trying some casing too. I'll probably make my own frame for casting and so some rough guards by sand casting. I do have a kiln so I might bight the bullet and try some wax loss casting.
Doug __________________ If you're not making mistakes then you're not trying hard enough |
#9
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"That's the problem with wanting to use a simple tin bronze, you usually have to end up making your own."
If I'm successful I think that's what would make it so cool. |
#10
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I made a makeshift foundry out of a small paint can, perlite, and furnace cement. Think it might work but the crucibles are so small I doubt I can get enough metal. That and the lack of easily attainable copper and tin, might have to go another route.
Found a place online that might be able to hook me up with some C905 tin bronze. Still working out if they can cast it thin like 1/4" or 3/8". Minimum order is $100 though. Anyone interesting in going in on some? |
#11
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Copper can be had at any hardware store. You can get tin at Roto Metals. Or you could just get something like aluminum bronze and melt it.
Doug __________________ If you're not making mistakes then you're not trying hard enough |
#12
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Really depends on how much I can get for that $100 minimum. Still working that out.
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#13
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wow not much. 3/8"x3/4"x10". $50. Looks like im back to casting my own.
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#14
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Any of the copper and copper alloys have become obscenely expensive. Casting your own from scraps is a very economical way to go. A small 1" wide by 1/4" deep trough in a piece of graphite will give an elongated oval bar that is already close to a basic guard shape. The molten metal will pull together so you don't even need four sides.
Notice the mold I used. |
#15
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how much did the mold run ya? My biggest issue right now is constructing a decent foundry, and am wondering if I should invest in a bigger forge/furnace that can perform foundry functions as well.
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Tags |
art, brass, files, forge, guard, guards, induction, kit, supply |
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