welding stainless steel exhaust

[GregWeld]

Mine is not cracked like that -- mine is tiny HAIRLINE cracks that just follow the part line (weld line) where the tubing was butted. It annoys me only in the fact that this exhaust system was several grand...

They hard mounted the system - and that was their first mistake - and I think it was that initial expansion and contraction with it being hard mounted that set up the hairline cracks... It's since been re hung allowing for some movement.

My system "grows" at least ONE INCH in length... And Tim came up with a masterful redesign of the hanger to accommodate that.

[badmatt]

Originally Posted by GregWeld

Mine is not cracked like that -- mine is tiny HAIRLINE cracks that just follow the part line (weld line) where the tubing was butted. It annoys me only in the fact that this exhaust system was several grand...

They hard mounted the system - and that was their first mistake - and I think it was that initial expansion and contraction with it being hard mounted that set up the hairline cracks... It's since been re hung allowing for some movement.

My system "grows" at least ONE INCH in length... And Tim came up with a masterful redesign of the hanger to accommodate that.

Hmm surprised they didnt do a fusion "root" pass then a cap..

/weld inspection theory.

[GregWeld]

Originally Posted by badmatt

Hmm surprised they didnt do a fusion "root" pass then a cap..

/weld inspection theory.

I guess a root and cap -- on tubing that's .060 or .080 wall ... and then grind it off and mirror polish?

I want to see what your cars look like -- you must have some AWESOME stuff!!

[badmatt]

Originally Posted by GregWeld

I guess a root and cap -- on tubing that's .060 or .080 wall ... and then grind it off and mirror polish?

I want to see what your cars look like -- you must have some AWESOME stuff!!

My stuff is all junk haha.

[frankv11]

My system "grows" at least ONE INCH in length... And Tim came up with a masterful redesign of the hanger to accommodate that.[/QUOTE]

Hard mount cross my mind but I also noticed on my truck that it reall grows quite a bit so I'm going to be running flex line at headers and at tips . its going to be hung real close go body with high temp grommets. Hopefully that will help a bit.
See you @ sema

[Vince@Meanstreets]

Im a big fan of those SS flex sections that RS and Marquez Design use. Look to those ring and rod style hangars. Seem to work well for the OEM's.

[GriffithMetal]

Originally Posted by badmatt

Hmm surprised they didnt do a fusion "root" pass then a cap..

/weld inspection theory.

Stainless shrinks a bunch when you weld it. If you pass multiple welds on the same seam the area will be lower. If you are trying to remove the weld and polish then there will be low areas where you welded. IMHO smoothed out stainless exhaust is for show cars that won't be driven much. It's expensive to build and has poor longevity. Leave the welds on stainless exhaust if you plan on driving it. Be sure to back purge the tubing or use a weld flux to prevent sugaring.

[Revved]

I've started integrating flex couplers whenever possible into my exhaust systems. Just like an OE system... anyway you can eliminate vibrations the better. Vibrant Performance makes serveral sizes and styles.

http://vibrantperformance.com/catalo...Path=1022_1064

[E.rodz]

a few thoughts for you one of the trucks that I built was done completely in stainless and I will not do that again for the same reason as Greg has stated I tig welded the whole thing and stainless warps badly from the heat way way worse . I tacked the whole system and then starting welding 1 inch random welds at a time it pulled so bad in every direction I had to cut many of the welds apart ad do the over again to make things line up where they were to go though hangers and such. the crossover pipe cracked in no time and that bright shiny look lasted about a week the it turns gold colored. if you bring it to some one to redo it in tig it will pull all over the place and the guy you bring it to will hate you for have to try to make it look good if he has to grind down all the welds. the more it is welded the more brittle it will become. don't weld it solid just tack it with the wire then tig it with a purge to prevent sugaring.tri mix gas is what you should be using for the mig. don't mean to disappoint just trying to help.

[frankv11]

Thanks to all for the Info.
My original intentions were to get a good solid weld with mig preferably (because I have no tig) but it seems more like I will need to get it tigged to get what I'm looking for. I'm not going to gring the welds down or polished it.

Now if I could weld it with mig and not get Sugar on the inside. I will gring just a tad ( no where near flush )