New masonry gasification arch build.

Nice work! Couple questions. How did you calculate the area and ratio of primary and secondary air? What material is your secondary air header made of? Definitely interested in doing something similar to this with my existing arch. Thanks.

Glad to hear it went so well. I can relate to lack of insulation. After the first season with mine, I had to go back and re-insulate the back of the ramp and stack base and the door. The door would glow red. I also added forced air over and under the fire. That is a bummer on the stack thermometer, but 1600 seems way too hot to me anyway. My stack runs 750-900, sometimes near 1000, depending on the wood. I've been told that flames out the stack indicate a lack of oxygen for the fire (unburned gases ignite when they hit the open air). I haven't had that problem, but do get smoke after reloading. What did you use for a door?

Casting and building my arch was something I wanted to do, and was inexpensive, but now that my production is greater, I am not so sure it was the best thing. Every design flaw means a loss of efficiency. A pro arch should have solved the problems build into mine, so if I upgrade in the future, I'll be looking at those. But, this is where I am for now. I'll be rebuilding the firebox this year (some bricks came loose), and casting a refractory grate. My steel grates melted as fast as I replaced them. Just about everything I have is homebuilt, and it shows.

Look forward to the pictures.

Here are links to two videos a made, a walk around tour of the arch. The day that I made the videos I averaged 12.75 gallons per hour.

https://youtu.be/SAn8MWFTWyQ
https://youtu.be/OQI22a6hAs0

vach50, I honestly just guessed, I have two 2" pipes delivering air under the fire, and two going over the fire. I built it to include butterfly dampers to control auf and aof, but I think it runs well wide open. There were a few sleepless nights, worrying about there not being enough air, but I figured that my wood stove has relatively tiny little air inlets, and that can get going pretty good. The header or manifold for the secondary combustion air is cast refractory concrete, Loucast 3000, or Mizzou or something like that. I got it from Sheffield Pottery in MA.

Thanks for the videos. I think an evap rate over 12 is outstanding for a 2x4 continuous flow flat pan. The first year I used my arch that's what I had, and I would say it averaged under 10, at about 7 or so. I built my arch for a 2x6 pan, so I had a plate on the rear two feet. But it was not insulated, and it warped in the heat. When I moved to a 2x6 hybrid pan, that plate got cut back to the stack base and everything got insulated better, including the door. My pan sits on a thick pan gasket, which sits right on the fire brick. I sized the inside of the arch so that the pan overhangs a bit on all four sides. A gasket would help with your warped base, and would help stop cold air from coming in under the pan. That should help with the efficiency. The fire looks good and hot, even without forced air (which you could always try to see if it helps at all). I like that door. Mine is from a barrel stove kit.