Charcoal Forges

[B. Norris]

I would like to have the opinions of others working with charcoal on the best kind of setup for a charcoal forge. Bottom or side blast? Does the side blast really make for fewer sparks than the bottom blast when using charcoal? Depth of firepot? Shape of firepot - should I have a gentle slope like the coal ones or steep sides as recommended by another smith? I can have all the oak scraps I could possibly want from a cabinetry shop. Free! I have made a few barrels of charcoal from it and am burning it in a "Lively Washtub Forge." So far I like it. Now, I am thinking of building a more permanent forge with a table to give me a bit more room to work. I am doing blades as well as general blacksmithing. Tools, hammers, odd stuff.

I was thinking something along the lines of this, just was not sure of the exact dimensions to make the firepot. Do you think, with this design, if you need a bigger, deeper, fire that some firebricks could be stacked in the trough on either side of the firepot and the work could be run through in the opposite direction?

[Alan DuBoff]

That looks like it would work just fine to me. In this case the firepot is taking most all of the heat, the firebrick is mostly insulating it. If you have a firepot, you're all set!

[ThomasPowers]

If I was adapting that forge to burn strictly charcoal I would probably line the firpot with firebrick splits---about 1" thick and then have loose firebrick along the top edges that I could configure as needed.

You need depth to get a good reducing fire but since *all* the charcoal is burning you don't want a lot of it that's farthur away from the work piece as it's only contributing to burning your arm hairs.

So I use a firebrick corral to keep the fuel from spreding out.

Thomas

[irnsrgn]

Two problems I see with the forge in the picture you put up.

1. The table should be bigger and the firepot should be in the center as charcoal fires don't concentrate in the center as much as coal fires and charcoal is lighter and harder to keep in a mound. 2 or 3 firebricks set on edge end to end will form a nice dam or wall to keep the charcoal from falling over the edge.

2. The blower needs to be moved back toward the operator and a little farther to the left unless you like slow roasted hand.

3. In the picture shown if you are working a long piece you will have to stand behind the blower and crank it with your hammer hand instead of you off hand.

[B. Norris]

The forge in the picture is not mine, it is just to show what kind of setup I am thinking about.

[son_of_bluegrass]

I can't say side blast makes for fewer sparks, but side blast works better for charcoal. A bottom blast will tend to blow the lit charcoal right out of the fire pot unless you have almost no blast which will leave the fire on the cool side for forging. Of course if you just run a pipe into the fire for the side blast the pipe will want to burn up.

For my set-up, I find 4-6" fire depth works about right. That gives me a hot spot a little bigger than my fist (roughly a 5" sphere).

If I was making a charcoal forge, I stick with castable refractory or fire brick (and I plan to as soon as I get some $$$). But before I finalized plans, I'd try different sizes, shapes, number and construction of blast pipes etc using ash or clay to decide what suited my purposes best.

ron