Topic: welding exhaust

[eldar]

I still need to seal my exhaust system but I need to know which weld I should use.
I know arc is too hot and could burn through if not done VERY carefully and I dont think I am that good.

So I am kicking around mig and gas.

I would think a small mig could do it without using gas but what have other used?

[mcpuffett]

hi eldar, mig or gas should be fine    mick.

[Cvillechopper]

I've been using a small Craftsman wirefeed mig set to it's lower setting and have had only minor burn-through issues.  As long as you're careful you should be fine.

[eldar]

OK I thought mig would be ok.

What I want to do, to keep the pipes in line the way I have them is to spot weld them using the mig. This way they stay aligned the way I want them.

Then pull them off and finish the weld.

Any foreseen issues with this?

[Cvillechopper]

Just make sure that you get a spot weld or two on each side of the pipe.  I had an issue with a change of angle because I only hit the top and side that I could see easily.  Other than that, should work no prob.

[eldar]

What setting did you set your mig too? What was the wire size?
I would seriously have to kick my ass if I burned the header pipes.

[Cvillechopper]

I've been using .30 flux core and my unit only has 2 settings, low and high.  The low is about 60amps I think, but I could have used a lower setting and been much more efficient.  Buying a cheap ($200) unit does have it's drawbacks.  Just remember, it's easier to grind off extra material than to add stuff you've burnt away.  I found I can weld as thin as 22 gauge sheetmetal if I build up starting about 1/8 in from the edge.  Less chance at melting the edge material.  Just a thought.

[Quail "Owner of the comfortable k8"]

You can weld a little thinner if you use a long extendsion cord.  The rise in resistance causes a voltage drop, yes the amps increase but it seems to work.  Also the fastest poss wire feed wil help weld thin.  It will not be pretty but you can get a build up that you can grind off and then weld normal.  I also use only Stainless it is stronger and it finishes nice.  It is very hard to grind.  After I grind I use the 4 1/2 sanding disk disk to smooth then I use the buffing wheel to make it look like chrome.  Sad part: the welding makes the area around the weld rust through in a few years (if your welding exhaust).

[mylittleho]

For thin mild steel tubing I like Oxy/Gas it's very clean and not much clean up..

But I have MIG(ged) exhaust tubing before also.. I can't remember the settings but I used a .030 Fluxcore with a Hobart Handler 125 worked BEAUTIFULLY.. Just remember to not overheat the metal.. tack it in like 3 places then slowly run like a 1/4" bead then rotate it and run a small bead on the next "tack" just go slow and take your time...

It will end up looking like BUTTER!!!

[eldar]

Well this helps me quite a bit. Thanks for all the tips.