Showerthought: Why my bead welds kept failing found the answer in a 5 minute video

I spent three days chasing a porosity issue on a 304 stainless tank job for a food plant near Detroit. Turned out I was running my gas flow at 18 CFH when the hose was over 30 feet long and the regulator was actually starving the weld. A buddy at the hall showed me a short video from Miller where they explained pressure drop over long hoses and it saved my whole Saturday. Has anyone else realized they were using the wrong gas setting for their setup length?

3 comments

3 Comments

aaronroberts1d ago

Blew up a $400 regulator on a job site once because I forgot to check the hose length. I was running 30 CFH on a 50 footer and the thing just freaked out. sethm58, you're right though, half the guys probably are fighting that and don't know it.

sethm582d ago

Man, that's a frustrating one. I bet half the guys fighting porosity are just fighting hose length problems and don't even know it.

william_craig72d ago

Miller's video on that saved me too a couple years back. I was doing a bunch of repair work on a pressure vessel and kept getting these little pinholes. Drove me nuts for two days. Turned out I had a 50 foot hose and was running it at 20 CFH. Dropped it to 35 CFH and the problems vanished. What gets you is most people think more gas is better but with a long whip you actually starve the arc. The gas gets turbulent by the time it hits the puddle. I keep a little card in my lid with flow rates for different hose lengths now. Cheap fix for a headache that'll ruin your week.