Gamble97
15+ Year Contributor
- 2,642
- 63
- Jan 3, 2006
-
small town,
Illinois
I'll try to make this short. A friend has a 4" FP FMIC. He cracked it, so he had a local place weld it. They hit it with a propane torch and said it was easier to weld that way then welded it. 2 weeks later it cracks on the other side. Brings it elsewhere and they did the same with the propane torch. I'm guessing they are cooking the impurities out of it??
He rewelded the entire thing! And guess what, it cracked yet AGAIN.So he asked if I could try. Figured why not. It's junk now anyway. I looked and the crack went through both welds and is about 10-12" long!
I lay it out and wire brush and acetone it. I heated it up with the torch because I am on 110v and can only do 125amps. Figured preheating would help me out. I cranked up the argon to like 30cfh, used 3/32 (red and tried blue) and used 1/16th 4043 filler. It took a few seconds for a puddle to forum but it did and I dipped and moved on. A few places seemed to weld like it was cast. Just didn't want to weld very good at all.
Anyway I get a bead and take the torch away and my brand new shiny bead has a crack right down the center!
Ok Let me try again on the other end of the crack. No matter what this thing was hot cracking. As soon as I was done welding my new weld was cracked from start to finish. How/Why does this happen and how do you prevent it?
Bastarddsm, - Yep it's joes. It's back on his car now until he gets a new one.
He rewelded the entire thing! And guess what, it cracked yet AGAIN.So he asked if I could try. Figured why not. It's junk now anyway. I looked and the crack went through both welds and is about 10-12" long!
I lay it out and wire brush and acetone it. I heated it up with the torch because I am on 110v and can only do 125amps. Figured preheating would help me out. I cranked up the argon to like 30cfh, used 3/32 (red and tried blue) and used 1/16th 4043 filler. It took a few seconds for a puddle to forum but it did and I dipped and moved on. A few places seemed to weld like it was cast. Just didn't want to weld very good at all.
Anyway I get a bead and take the torch away and my brand new shiny bead has a crack right down the center!
Ok Let me try again on the other end of the crack. No matter what this thing was hot cracking. As soon as I was done welding my new weld was cracked from start to finish. How/Why does this happen and how do you prevent it?
Bastarddsm, - Yep it's joes. It's back on his car now until he gets a new one.