MIG 304SS pipe to mild flange (exhaust)

[SgtRauksauff]

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

[zapster]

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!

[SgtRauksauff]

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

[zapster]

no problem

...zap!

[Rojodiablo]

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
Go for it!! Get a spool of .023 wire, and have some fun. I recommend the .023 because of the thin exhaust tube wall. If you are worried about the filler, just add more.... but the .023 gives a nice small bead.

[SgtRauksauff]

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

[TubularFab]

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!

[TubularFab]

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...