Has anyone thought of this, for the hobby craft though scaled up it should work for the pros also.
For many people the cost of electric is high, or availability low for high powered stuff. I'm working towards getting rid of the grid myself, go wind and solar power instead so of course I don't want to be adding High Demand electric items if I don't have too. I could never go off grid and power an electric oven large enough to do cycle frames!
Propane is like gasolene, the price is everywhere and never the same 2 days in a row, never low like it used to be. Perhaps a 20lb tank runs my cook stove about month, was $8 to fill the tank a few years ago, I think now about $14 to fill same tank. I never had a large 250gal or bigger tank installed, just not using that much gas here to be worth it. I don't want to be baking with $14 20lb tanks much.
Now, wood or charcoal, well that's pretty cheap here, almost free for me. Is free if I cut my own wood, other than the time and a little oil etc...
I use an electric chainsaw and batteries carried in my truck bed are charged from wind power when not in use.
So I am thinking, build a firebox outside or in a safe place. Pipe the heat into the oven several ways. One is to run 2 pipes, 1 top 1 bottom to the oven, flow the heat up off the fire box into the oven with top pipe and draw air from oven to firebox with bottom pipe. This should create a gentle airflow in the bake oven, keep the heat equal top and bottom, the pipes are just recirculating the oven air, so other than powder dust the pipes should stay clean. The fire would not be near the loose powder so safe there.
When we cut off air flow to a fire it goes out, so the fire box sealed we can shut down the fire by closing a damper. When we blow air into a fire and fan the flames the fire burns hotter, heck we can melt and cast aluminum with plain wood charoal, I've done that
So if we install the thermocouple in the oven, use it to controll a small fan at the firebox to fan the flames, it would seem that we could control the oven temps still pretty well. When oven is too cool fan runs, fans the fire, lots of heat made. When oven is hot enough fan shuts down, restricted airflow to fire keeps fire burning with lower heat untill more heat is needed and fan runs again.
Depending if a cheap source of fire feul is available or not this could save allot of money on power bills for some people if properly built. Some places like CA. may outlaw fireplaces and woodburners so maybe not usable everywhere.
Built correctly I think for a home hobby shop or even the pros this would work well. A fire could be built up on say Friday night and just kept going all weekend so oven is always preheated and ready to work.
With a large fire box it's just a matter of load it, light it, forget it, for as long as the load of wood burns. So larger firebox load once in morning or evening. Smaller fire box you may need to load 2-3 times daily.
How well something like this might work depends on the work habbits and parts. For baking for 1 hour a day a few times a week, maybe not worthwhile.
If you'll be baking parts all day and half the night for the whole weekend it may work very well.
For a LARGE oven for cycle frames, trailer frames, etc... the power savings might really add up fast even for just a couple parts. For a couple nuts and bolts, not worth it.
As for polution, wood is a cleaner heat source than the feul used by power plants. Electric is wrongfully thought of as a clean power because people do not see the polution right at their home, but most electric production is not clean!
Also wood is re-newable where as coal and oil are not. So if it works for you well then wood is a better choice for more reasons than just saving money!
In the money aspect of a wood oven, that would vary for everyone. I saw in a post some-one estimated it costs them $1.08 to run their oven for an hour.
Figuring if my cost were the same, then to bake 8hrs on Sat. Sun. 16 hours total would be about $17.28 per weekend or $69.12 month with 4 weekends in a month. For $5 I can buy enough scrap wood to last a couple months of weekends from a local sawmill plus maybe $10 for my gas to haul the wood home. I only used about $25-$30 of the same wood to heat my home all winter. So the cost to just keep an oven fired all weekend would be almost nothing here.