GMAW Aluminum Welders

admin

Just wondering how you guys GMAW aluminum without the problem of Cold Start. I do not get full penetration at the start of the weld. Once I am welding, the weld wetts in fine. Using the Hot Start feature does ok on 3/16” and under but does not satisfy the condition with thicker material.AWS allows for a preheat of 250 F. but does not recommend it.It isn’t a major problem with most welding jobs but my latest job spec’s 100% fusion with the welds as it is a Safety Item. It is totally impractical to TIG weld this job but that would solve the cold start problem.I am welding 6061 American Standard Structural Aluminum with the thickest material at .320”  Using Lincoln Power Mig 350MP with dedicated Python Push Pull gun, 3/64" 5356 wire, 100% Argon.Any suggestions.Thanks.
Reply:I keep an auto start Mapp gas torch when I have to start a weld on aluminum if the piece is big/ thick, or if I have to mig it. I only preheat the first couple inches, and it doesn't take too much, maybe between 10 seconds and 30 seconds depending on the part. With mig, it makes all the difference in the world!And then, after so much work...... you have it in your hand, and you look over to your side...... and the runner has run off. Leaving you holding the prize, wondering when the runner will return.