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Cold weld?



undercut
05-23-2012, 12:33 AM
Totally noob question. If I grind my weld down and there aren't any inclusions, no porosity and I can't tell where the two pieces of metal and filler material start and end ... could the weld still possibly be a "cold weld"?

KHK
05-23-2012, 12:10 PM
Welding heat is about penetration. You will have to cut the weld to see what the penetration is.

Xalky
05-23-2012, 12:48 PM
It's almost always better to go too hot than not hot enough. You can always back off if you weld a hole. Most of my experience is with mig welding, I've welded some pretty thin stuff with mig wire thats too heavy by simply welding it a small bit at a time and then giving it a second to cool off and continuing, repeating that process. It's fairly easy to do with mig. A little tougher with tig. You don't want to find out your weld is no good when it's in service.

undercut
05-23-2012, 01:08 PM
It's almost always better to go too hot than not hot enough. You can always back off if you weld a hole. Most of my experience is with mig welding, I've welded some pretty thin stuff with mig wire thats too heavy by simply welding it a small bit at a time and then giving it a second to cool off and continuing, repeating that process. It's fairly easy to do with mig. A little tougher with tig. You don't want to find out your weld is no good when it's in service. I was using a stick welder. Turned out it was defective. Returned it and I'm in the market for a (better) new one. The weld it did produce looked a bit "cold" so I ground it down and I couldn't tell where the base metal started and the weld ended. Does that indicate sufficient penetration? I'm not doing anything structural - just taking the opportunity to learn about how to read these things.

Xalky
05-23-2012, 01:17 PM
If your just practicing on scrap. Throw it the vice and whack it with a hammer and try to break the weld. If its a good weld, you'll probably bend the piece before the weld breaks. If it's a crappy weld the weld will crack or break. Highly technical stuff...LOL.

undercut
05-23-2012, 01:37 PM
If your just practicing on scrap. Throw it the vice and whack it with a hammer and try to break the weld. If its a good weld, you'll probably bend the piece before the weld breaks. If it's a crappy weld the weld will crack or break. Highly technical stuff...LOL. That first weld, while not critical, was on something I'd rather not whack. Once I get my welder, I'll take your advice and do some destructive analysis ;)