air in the fire

[evfreek]

Originally Posted by Glenn

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The wheel forge took 45 minutes to build. After 25 minutes of burning only wood I had metal up to red heat. That is 1 hour and 10 minutes of investment. I can report that the forge does work, but my version needs improvements. See BP0462 for details and a solution for using wood as a fuel.
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Hi Glenn. Experimenting with using wood to forge is very interesting. Once upon a time someone posted on his experiences with wood pellets. He was able to get a pretty good heat. There is some kind of rule I heard of like 6-10X the fuel size for the firepot depth. That is why it is so hard to get a hot fire with big pieces of wood. The fire behaves like a shallow fire. Cold and oxidizing.

Actually, it is a little more complicated than that, and the scaling is non-linear in the good direction. In other words, the rule may become more relaxed with larger size fuel. I saw a wood fired forge in action that could get up to a sparking heat with scrap wood (like pallets and construction scrap). It had a firepot that was about 3 feet deep. Hmmmmmmmmm, this is about 6-10X.

This may help to guide the direction of your experimentation.

[Glenn]

I have run the Supercharged 55 Forge (Blueprint BP0333) on pallet wood, yard waste, and I even ran a whole apple tree through that forge. (grin). See post #25 this thread for a photo.

Your mileage may vary, but with my set up, the good size for wood seems to be a 2x4 and maybe 4 inches long. Smaller than that size is even better. This allows the wood to burn, form charcoal, and form a hot bed of coals. This not only heats the metal, but burns the wood creating charcoal to continue the process.

It takes a LOT of wood to fire a forge. On the plus side, your yard is clean of sticks, the woodlot is clean of ground clutter, and you make a lot of business happy by hauling off their old pallets.

Find a fuel and then build a forge to use that fuel. The experimentation is fun and you learn what works and what does not.

[IronPuppet]

irnsrgn said a couple of things that stuck in my head. One was that my stock was probably too thin, the other was that the sides should be sloped at 20 degrees and the front and back sloped at 35 degrees.

My new fire pot will be made of 1/4 inch steel plate. I got it from a friend who was dismantling some big "I" beams. The stock I got is long bits about 4.5 to 5 inches wide. To save on gas for the torch I cut out the pieces as shown below. now they are all ground up and flattened out and I will weld them together to make the 4 sides, then weld the sides together to form the fire pot. This will make the steel part of the fire pot just over 4 inches deep. The top 1 inch will be made up of clay. I also have bricks to make the sides taller for some uses.

This is where I am at right now. Due to the fact that I am welding the parts together to make the various sides I was wondering if there is any advantage to making the side parts rounded. Weld then together on a slight curve. This would give the fire pot a rounder shape rather than square. what do you experts think of that?

Christopher

[irnsrgn]

your getting there, forget the curves. if anything make it wider and longer. so you have more area at the bottom. Charcoal needs a bigger firepot than coal or coke.

[Glenn]

I fired up the Supercharged 55 Forge Blueprint BP0333 on only wood and remembered to take a photo. It does reach forging temperature.

[IronPuppet]

That's good, Glenn. I'm glad to hear it. I got lots of scrap wood.

Got around to putting my new fire pot together today. See what you think of this now. Seems big to me. Could be made smaller with clay. I think I'll make the hood removable so on good days I can take it off and also to store it away.

Christopher

[irnsrgn]

Looking good Chris, you really are Forging Ahead Now.

[IronPuppet]

Thank you so much, irnsrgn! I couldn't have solved so many problems so fast without your guidance. I appreciate your assistance more than I can express.

It's a privilege to know you.

Christopher

[Strine]

I dunno about the extra clay. It seems to me from the photo with the squirter tape that it would be deep enough without it. Just tack it/bolt it or otherwise join it to a plate to fit inside the wheel. Leave a bit of the wheel proud of the plate and you have storage for fuel.

What about burning out the pot...no worries...knock up another one.

[Pault17]

Hey Ironpuppet,
thanks for the thread. I keep thinking of makiing a charcoal forge, as soon as I can get a place to work outdoors without fire concerns. This whole conversation has been very enlightening and educational. Not that I expected any less from everybody here.

thanks again