MIG 304SS pipe to mild flange (exhaust)

admin

Hi there!  excuse my complete n00bishness.I tend to do pretty decent welds when working with most of the stuff I've tried so far, but that's been all scrap metal doing little things (welding cart, motormounts, car door hinge, dad's exhaust pipe, small stuff like that).I've now got a 304 stainless downpipe to install, and would like to know, is it possible or worth it weld it to a 5/16" mild steel flange, since I've got a bunch of them?Should I just go get a small spool of wire, like 309, and start raising my electric bill?  (I saw that 309 was suggested when asked about this same question, only regarding a TIG process, so I'm assuming (and showing my overabundant lack of knowledge) that the same type of metal would work in a MIG process).I appreciate any suggestions.Now, off to read more.--sarge
Reply:if 309 is available for a mig i dont see why not...but...i'm thinking it would only be available (if it is at all) in solid core therefore you'd need a gas machine...fluxcore..i dont know......zap!I am not completely insane..Some parts are missing Professional Driver on a closed course....Do not attempt.Just because I'm a  dumbass don't mean that you can be too.So DON'T try any of this **** l do at home.
Reply:I've got a gas machine, it's a lincoln 175-plus 230V, running ArCo2 (75/25 I think, but I'm not 100% certain now that I think about it.)thanks!--sarge
Reply:no problem...zap!I am not completely insane..Some parts are missing Professional Driver on a closed course....Do not attempt.Just because I'm a  dumbass don't mean that you can be too.So DON'T try any of this **** l do at home.
Reply:Originally Posted by SgtRauksauffI've got a gas machine, it's a lincoln 175-plus 230V, running ArCo2 (75/25 I think, but I'm not 100% certain now that I think about it.)thanks!--sarge
Reply:I appreciate the input guys!I've been using .030, not really sure why, but probably because I got tricked by the "bigger is better" sham.  I think I will try some .023 because I have burned through about 3 or 4 times when working on exhausts so far.  Nothing really major, just some extra time to fill in the hole.--sarge
Reply:It will weld much better if you get a stainless gas mix - Linde/Holox calls it "stainless trimix".  The bottle says it's 2.5% CO2, 7.5% argon, and balance helium.  With just regular mig mix you'll find it had to get enough heat - the bead will ball up and make an extremely cold looking weld.  Migging stainless is a strange beast - have fun!Last edited by TubularFab; 07-27-2006 at 03:48 PM.
Reply:BTW - You'll find the ball on the end of the wire after you stop welding many times has a non-conductive tendancy.  You hit the trigger and it acts like you have no ground.  Snip the end of the wire off before each weld...