Help me settle a disagreement (welding related)

Btw nothing on a hotrod requires a full pen weld. That's all astme section 9 bullshit.

 

FWIW, I was taught a weld was twice as thick as the metal to be joined including penetration.
But, I think speedmetal is bound by a lot more stringent rules than I have ever had to work with.

 

Although Im in agreement that most of the time on a hot rod you aren't gonna need welds that are 100% penetration but on a roll cage that needs to be x rayed to get a cert I dont think anyone is going to disagree that isnt a place to leave something to chance. The conversation we were having was about a crazy tube frame drag car with 100s of feet of tubing in it. It moved towards how I said it was difficult to get a full penetration weld in some of the joints the car hadcause the angles were so tight and alot of tubes were converging at the same spot. The other guy quipped that it wasnt as hard as I was making it out to be and thats when we got into tthe disagreement about weld penetration. So although I know that building a car normally doesnt require the same amount of attention in the welds as say nuclear pipe, things like roll cages do still fall into that category.

 

theres a difference in full penetration and propper weld temp, there are too many metallurgical variables to list, but in my exprence most tig welds that fail on 4130 tubing is caused by crater crack which later leads to weld failure.

 

Tee this, lol. There's no full penetration, IMO.

 

good god, thats the exception lol.