j.w.s. Posted June 20, 2012 Share Posted June 20, 2012 This is my first time attempting to build a gasser from the ground up so there's still some refinements needed. I'd appriciate any input. Currently I'm having a problem getting it up to welding temp - it's almost there but not quite to my happiness. Also, you'll notice I'm using 2 venturi's and 1 forced air burner, this is really just for testing purposes but we haven't decided which way to go. For years venturi's were fine for me but I'm leaning towards the forced air. The internal dimensions of this build are 8x24. The whole build started with three old propane tanks that we made sure were empty, removed the valves then filled with water to ensure there was no lingering gas inside before we started cutting. Each section was marked, then cut to form interlocking segments. The segments then needed to be trued, marked again for final fit positions. We decided to cut three burner holes with the plasma, figuring that it was easier to plug then it would be to cut more holes after the refractory is cast, we also cut our back passthrough. Our refractory is Vesuvius 3000, mixed about 7:1 with coarse vermiculite. We weren't sure about our ratio and after everything was done we estimated we could have almost doubled the vermiculite and still established solid walls but we still don't know how it would hold up at welding temperatures over a course of time. To cast the mixed refractory we used an 8" concrete form, poured around it then tamped down our layers until a small amount of slick appeared. For the door I took a bottom from a propane tank, cut our opening and used two pieces of 2x4 as forms. I welded small steel hooks on the inside to hold the refractory in place. All refractory was allowed to set for about 36 hours, after 15 of which I removed the center form from the main body - the wood form for the door was left in, later I drilled holes through it and we burnt it out with oxygen from a torch during a test burn. I manufactured a forced air burner from some schedule 40 1.25" pipe and a hair dryer. The gas orifice is a 0.023" MIG tip tapped into a cap on the end of a 1/4" pipe length. For the end of the burner I took a smaller diameter pipe 3" long, some threaded rod and a 3" length of 1/2" solid rod and welded them in place to create concentric rings at the end of the burner, essentially to lower the pressure at the end of the burner to keep the flame from drifting from the mouth. I later repeated this for the two venturi burners from our donor forge. The first fire was for about 5 minutes with just the forced air burner, after completely cooling we repeated for about 20. We gave it a day to rest and the following morning we started subjecting it to full fires, first with the forced air burner, then adding a venturi. After adding the later both burners seemed to burn more efficiently. Finally we added the second venturi to the body and fired with that. For the floor of the forge we added kaowool to support our two 3x12 welding plates. As is the forge works well and for a general smith would be a dream but still needs some tweaking to get to get it to welding temperature. Currently it's looking about 100 degrees off from what I'm used to for welding Damascus billets. -J Quote Link to comment Share on other sites More sharing options...
Robert Yates Posted June 20, 2012 Share Posted June 20, 2012 Nice Build and cool set up Sam Quote Link to comment Share on other sites More sharing options...
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