Welding Tips and Tricks

Hey guys. I'm spool gunning but I thought it would get more looks here. I'm fixing a deer guard I recently built. It was on his truck for a couple weeks and got hit by a car. I've wire brushed the joints, used an aluminum oxide flap disc, and acetone. What else could I do? I seem to still get a sooty, black, porous weld. I also see some green colored gas looking stuff coming off the welds. Any ideas?

If you have ruled out all the obvious stuff i.e. shield coverage etc. You might just have nasty fouled aluminum. As a last resort when I weld aluminum diesel fuel tanks that won't cooperate I try an old timers trick that sometimes works. Turn on just the acetylene on your torch and soot up the area, then turn on a high carburizing flame and burn off the soot. Do this a couple times and see if it welds better. It is really an annealing trick but sometimes it helps welding crap aluminum.

Thanks for the tip man. Never heard that one. I got a little aggravated and picked up a piece of the guard that was broken off and didn't clean it or anything and it welded the prettiest weld but as soon as I tried to weld one of the joints on the face of the guard no dice. I'm suspecting it's just crud from everywhere this thing has been. Gas, exhaust, bugs and all other kinds of junk is probably the problem.

DLewis0289 wrote:If you have ruled out all the obvious stuff i.e. shield coverage etc. You might just have nasty fouled aluminum. As a last resort when I weld aluminum diesel fuel tanks that won't cooperate I try an old timers trick that sometimes works. Turn on just the acetylene on your torch and soot up the area, then turn on a high carburizing flame and burn off the soot. Do this a couple times and see if it welds better. It is really an annealing trick but sometimes it helps welding crap aluminum.

Ive done that to anneal but never to help clean cruddy material...Ill keep that in mind.

Did he drive any where there was ice melt. Green gas / smoke makes me think chlorine or chloride salts.

He may have but I'm not sure. I think his trips are usually to the south. After working on it some today it seems like if I welded it and ground it out and welded it again it did better. I guess just contamination. I had a friend tell me he thought the contamination could possibly be 1/16" deep? Not sure but I got it straightened out today. Thanks for the replies.