Original Posted By: Alan Swanson
I am inclined to agree about the heat affected zone business. From my reading, ...and experience in welding up my super ace fuselage.They say that one should uniformly heat the tubing before welding...to avoid warps, and to uniformaly adjust the metal to the welding temp. Also one should cool the tube slowly after welding to avoid air hardning of the 4130 steel tube...which IS an air hardning steel.The mig will probably do fine to keep the tube from wiggling(like a snake !!) but I am reasonably sure that you will encounter brittle welds using mig from the air hardning nature of 4130 tube.Also from what I have read, they say one should normalize the steel after welding with a mig to avoid this problem. You normalize with a oxy act welder.Information I relate is from EAA book on building ACRO SPORT aircraft...Title escapes me right now.bob>From: Bill Talbert >Reply-To: Pietenpol Discussion >To: Pietenpol Discussion >Subject: Welders?>Date: Sun, 04 Apr 1999 19:46:56 -0500>>Hi Folks;>>I am getting closer to the production stage, one item I>still do not have in my shop is a welder. I am thinking of>going with a wire feeder. More for power requirements than>anything else. I understand these units can run on 110v/ 20>amp. and are somewhat compact. It sounds like some of you>have welders and use them a bit. I am sure this is>something I will use from now on, that is why I am thinking>of buying a good one. Does anybody have a recommendation or>warning about anything on the market? I figure if I get the>big ticket items bought first, the boss will not notice to>"total cost" of production.>thanks>Bill>________________________________________________________________________________