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Stainless steel forge


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I'm considering building new gas forge using stainless steel material instead of iron (as the outside frame of the forge). The motivation is better energy efficiency since the stainless steel has better emissivity coefficient (lower than iron) as well as lower thermal conductivity(than iron) so the heat loss to the environment should be lower. In addition the stainless steel is more durable from oxidation/rus point of view. 


I would appreciate any advice on this issue. 


Best regards,


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Gas Forge using Stainless Steel ?   I'm confused.  You would need to insulate the forge in any case using some sort of refractory that would hold in all of your heat.  The shell, being made of iron, stainless or dirt just acts as an embodiment for the materials you use to hold in the heat.  I would think an extra inch of insulation would have much more beneficial effects for forging than using a stainless steel shell.   Sure stainless steel is awesome, and if you can afford it or have it available and can work the material, then by ALL means, go right ahead.  But I think you may be over thinking the whole situation.  A painted steel/iron frame should be plenty effective, and for what you would spend on the stainless steel + welding wire, you can simply buy an extra inch or two of insulation such as kaowool, cerablanket, kast-o-lite or what have you.  I don't know what "emissivity coefficient" means, so I don't know what to tell you about that, but I think more insulation you have will always be more efficient in forging applications since if the heat can't escape, then you don't have to worry about what's past the insulation.


If you want to use stainless, Then Go Right Ahead.    But I don't think it will offer that great of a fuel savings if you are only using minimal insulation.


I can almost guarantee that a properly built forge will never get through to your outer shell.  Unless of course this happens:

I assure everyone that recognizes that forge in the pic, that the damage was due partially to my lack of knowledge on the subject plus unnoticed shipping damage.    The manufacturer in question made it right 100%.




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Unless you have plenty of experience don't bother, especially if this is the first forge you are building. 


1. Stainless works totally different than steel and requires special techniques to avoid extreme distortion. 


2. Your insulation is far more important than the heat conductivity of the shell. Spend the extra money on an extra layer of kaowool. 


3. Because of the distortion characteristics of stainless, you could have total eventual failure after somewhat prolonged use. 


5. Always make prototypes from steel, ferpected products from stainless. So much easier and cheaper to make changes until you know just what you want. 


Finally, if the stainless is free, up size it a couple thicknesses and go for it. Most of the problems with working stainless are easily overcome by simply using thicker metal. 


Any thing over 11 gauge (1/8") .125" (3 mm) is relatively easy. 


Edit, sorry Bruno, I see you made many of the same points. 

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Sure, I prefer SS for the reason's you state but it only applies to the shell, not the frame. SS is harder to work but not a big thing. Drill and pop rivet and don't worry about welding it. Use SS rod and a stick welder if welding is a must. You'll want white bi metal saw blades and hole saws and good drills, cobalt are pretty trouble free.


Go slow, SS is chewy and will destroy your tools if you push it. There's nothing magic about SS, it's just another skill set so it's a fine step on the learning curve.


Frosty The Lucky.

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