MIG welding frame mods?

glad i came across this thread... i only weld using flux core and i'm now considering the konging.

justinz830 wrote:

With your welder you should have no problems making a strong weld as long as you're getting enough penetration.

Generally speaking with "hobby" type MIG welders this will be the stumbling point. "Hobby" MIG's that put out approx 120-130 amps are not enough for frame tubes. The weld penetration is simply too cold. To ensure quality weld fusing, the only real solution is TIG.

for mild steel tubing only 120 or 130 amps is more tham enough to produce good quality welds as the average stick welder is only run at 110 for a an 1/8 inch rod

dude a mig is fine, I mig'd a frame for my Harley ironhead and its holding fine and those suckers vibrate, I got a lincoln 135

stonemaster wrote:

dude a mig is fine, I mig'd a frame for my Harley ironhead and its holding fine and those suckers vibrate, I got a lincoln 135

+1
My Lincoln 135SP will burn through my frame in a heartbeat if I turned it up. I used it for all my frame bracing and mods.

Innershield wire should be fine with structural welds in frames. A small 90 amp welder can be slightly under powered for the tie-in at the solid wall of the tube. Good fit up is critical for all good weld joints! Each weld should be beveled to have a 45 degree included angle. Use wire that is rated as 60,000 psi tensile strength minimum, this is very important. Mild steel is rated for 58k-80. If during setup and practice, you have a hard time getting good penetration, preheat with a propane torch to about 400-500 F. Turning the amperage up, lowers the OCV (open circut voltage) which affects penteration. Would definitely recommend using a small diameter innershield wire and lower amps to help keep voltage up.
Dualshield (innershield wire and shield gas) would of course be better and is the industry standard today.
An acetylene torch can be used for good tube repairs. This is my preferred method personally. Always use high quality filler rod from a welding supplier, not coat hangers.