BigBearLittleBear

I just installed stainless works long tube headers and cats. Other work had to be done to exhaust to make it all work. There are a lot of clamps in the system and I have tightened them down well. I hear a lot of leaking primarily when under moderate to heavy acceleration. It sounds absolutely terrible. At idle you can't really tell where it is coming from. My friend has a mig welder and says he can weld it all together, but he doesn't have any gas to do a good weld. I am wondering what to do. Use regular mild steel and wait until I can properly weld it or just live with the leaking until I can weld it properly.

elricfate

https://smile.amazon.com/Permatex-80.../dp/B000BOAZM8

J15

Use the permatex listed above. Thoroughly clean all surfaces prior to application. Let it sit a few minutes after laying the bead before assembling the exhaust. That lets it firm up a bit so it doesn't squirt everywhere and leave gaps in the seal. When you clamp everything down, only go 90% of the way. You don't want to squeeze the permatex out of the gaps. Resist the urge to fire up the engine right away. Let it cure overnight and finish tightening the clamps in the morning. When I worked in a motorcycle shop this is how we installed slip on exhausts and it worked very well.

STingray1300

The "stainless" steel used in most exhaust systems is 409 stainless. That means that it has just enough nickel content to be categorized as stainless. Mild steel welding isn't really going to hurt it, but in the long run the mild steel weld may leach rust into the exhaust weldment. I suggest using some 309 welding wire. A 2 lb roll might cost about $15-20. But then your friend will need some tri-mix gas (used ONLY for MIG welding stainless), CO2/Argon/Helium. And the helium is getting really expensive these days, making the tri-mix not a cheap item anymore.

My suggestion? Go to a muffler shop and drop a Grant on them to do the job right and spare your friend the headache(s).

-OR-, I'm doing 2 welding jobs tomorrow, stop on by and I'll TIG it for ya.

channelbass

I would hold out for somebody that's a competent tig welder. I think exhaust shops are hit or miss, seen a lot of blind bubble gum welds from shops. Using the correct filler metal would go a long way to avoiding joint failure. I like to pulse tig lighter gauge stainless.

tinner1

iTrader: (7)

Tig it with 1/16" tungsten and argon gas and depending on the fit of the joints from1/16" filler rod for tight joints or 3/32" for poor fitting joints.Silicon bronze could also be an option, flows like water but is much weaker than stainless. Stay away mig with mild steel, dissimilar metals not good.

Some of the muffler shops around their welds can't hold popcorn, good luck.