Start with simple Ts, then angles, then clusters, etc. Thickness is similar and it's a little easier to heat without blowing through. Just wire brush off the galvanizing about 2' back and have at it. For cheap practice, before burning up a bunch of 4130, play with EMT. You will not master it in a week, but it is a skill you can learn. I can explain this all day long, but it's like playing a piano. Main thing is to not overheat the tube or undercut. 01%, just a barely visible feather) to prevent oxidation due to regulator wander, and to cause the surface to melt slightly before the rest of the tube.Į70S filler rod, 1/16 diam, copper coated. Go just EVER so slightly to carburizing (I mean. My technique is to get a staright acetylene flame to stand just off the tip and back off a touch. Pressure is a function of tip size, so look in the mfgrs book. Victor, Smiths, Purox, Airco, any good name brand, so you can get parts. A Purox 200 or similar will do anything you need. Don't try this at home kids.Īs for the torch, anything will work, but smaller is easier to handle, gets into tight places,and doesn't wear you out. Actually, some Stinson frames were STICK welded! They had an approved procedure for that, though.

OA is the only certified field approved procedure for aircraft frame welding, as is. If you have to break out the torch anyway, why not just weld it?Īny approved procedure can be used, if you know what that procedure is and have the paperwork to back it up. TIG is allowed, but you have to go back and normalize the structure at all the joints with an OA rosebud.

Welding 4130 standard notes