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Firepot Question


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I'm working on getting my new forge just right. It's a large brake drum forge, as you can see from the early picture which is a little difficult to understand as the plate is not bolted to the drum and the grate has not been drilled into the stainless steel. It has a 4mm steel bottom with a 1/4" stainless plate with the grate drilled into it which attatches to the air pipe underneath which is also stainless. I lined it with a couple of inches of fire cement to give it a lining and to make a firepot shape in an otherwise flat forge. I burn coke.

Unfortunately, the fire cement that forms the firepot gets impregnated with clinker and cracks under the heat, leaving me with a bigger and bigger firepot! I need something that will not need to be relined all the time and is easier to clean- this is the plan. Chip away most of the cement, weld up a rectangular firepot out of 1/4"-1/2" sheet steel, about 3" square at the bottom to leave the grate and some of the stainless surrounding it exposed, then seal the pot in place by surrounding it with fire cement.

What worries me is that the heat that this produces is ridiculous. First of all, will the plate be up to the job? Second, although the bottom of the forge is protected with fire cement, the stainless plate is exposed to the full heat of the fire and bolts to the thinner plate, heating it up. Am I being far to cautious or should I be worried about this? I've even considered ways of cooling the bottom, I have the most powerful 24V fan known to man which I could point at it, I've even considered some kind of watercooling jacket around the top of the airpipe to conduct heat away rather than heating up the plate.


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If you have the tools to weld up a fire pot out of steel, why are you using a brake drum?

The fire pot grate at the bottom can be a piece of 1/4" plate just like the sides of the pot. I prefer mine to be removable, though.

Sealing with fire cement isn't necessary at all as any cracks or crevices would soon fill with ash.

Unless I'm missing something in your post. Seems like the best thing you could do would be to weld up a fire pot using the thickest metal you have on hand. Then sink that fire pot into a thin sheet metal table top (cookie sheets work well, as do 55g drum lids, and doors from appliances). Not only would that give you a simple forge, but you'll love having a fuel storage area off to the side.

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Using the brake drum primarily to save space as I am extremely challenged for it! This brake drum is huge as it's from a bus, so I can have a 7"x8" fire pot with plenty of room for storing that coke to drag over.

My concern is for the 4mm plate along the bottom, I'm worried that it will overheat due to the heat coming through the stainless grate which is bolted onto the 4mm plate and cause it to sag.

The fire cement is to fill the space- it raises the bottom a few inches and allows for a firepot to be installed.

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The 4mm plate will burn up and degrade with time, but that's going to be a long time. I'm not familiar enough with stainless steel to say how it will take the heat, but I'm confident that it will do better than the mild steel.

The large brake drum is what stumps me, though. That's a lot of weight that serves no purpose because you're putting a fire pot inside of it. Space being at a premium, as you say, I can't see how using that "huge" drum helps. As a forge, on it's own, it is simply too large to function effectively as a fire pot; that's why you see folks using smaller drums from cars and trucks. If you have the capability to weld up a fire pot like you see sold commercially, placing that fire pot into a cookie sheet or dryer door won't appreciably increase the forge's footprint. What it will do, however, is give you a lighter forge that's easier to move around and has room to the sides for tool and fuel storage.

Of course, that's just me thinking out loud.

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New member here...I have been reading on here for a few weeks now.

I am in the process of collecting the parts and pieces to build a forge in the next few months. My first plan of attack is practice then building my self some basic tools to use. I have read many of the forge building posts here and can't seem to answer the following question...

Mant posts say a 10"-12" brake drum is too small and has no extra fuel capacity but a large {lets say 18"} truck drum is too large. A Centaur C-36 forge has a 8"x10"x4" bowl (smaller than a medium brake drum), is this forge too small also? These all seem to be contradictory statements, what am I missing.

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What you are missing is that the centaur forge firepot gets mounted in a forge allowing fuel to be piled around it even higher. A lot of brake drum firepots are used alone and so limit the depth of fuel used.

You can of course mount the drum in a fireproof table set up and so use it only as the firepot. Or you can put in a sheetmetal fence to make it deeper but still have access through a gap to the hot spot.

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