just to preface this, i'm a VERY competent MIG'r, i did the entire frame of my minibaja senior project.


so this was my first attempt @ flux-cored w/ my brand new lincoln FC/MIG.
i had a giant crack in my turbo manifold, and i did my new 3" exhaust at the same time.


(i also posted this in the FI section awhile ago, but all they did was bash the manifold. the only thing i got outta it is maybe my exhaust isn't braced in enough places) hopefully other welders can have better insight tho


original crack:



the crack was also spreading along the turbo flange, which is why i did that. personally, i was impressed w/ the horizontal weld, and how similar it looked to MIG.


but in case your eyes aren't too good, the same exact crack came back at the same spot.


and my disgusting exhaust, which is holding up fine so far:





critiques/advice? is there something i forgot to do that caused the crack to come back immediately?

 

what pipe did u use on ur manifold and what type of flux core r u welding with?

 

I would take a grinder and grind out the weld first then fill in the gap with weld. If you just weld on top of the crack it doesnt penetrate enough.

 

.035 innershield NR-211, on 18g pipe. sorry idk what sched. it is, but it's a typical log manifold.

hmmm gotcha, that makes sense.

 

looks like you just started mig/fcaw IMO

 

your log made from stainless steel?

 

I bet you didn't prep the bevels. am i right? also that can't be 18g i'm guessing it is pipe correct? that is measured in schedule 10, 40 etc...

For pipe (which you most likely have.)
You need to add a much larger bevel then the one that is on the bends from the factory. It is a starting point you could say. I go anywhere from 1/8"-just under a 1/4" wide bevel on my manifolds.(this is on each piece not both) the landing(area that they touch at) should be maybe 1/16th or so. this gives you good weld penetration and enough area to fill in to make a strong weld. (the more surface area the stronger the weld)

If it was me I would call this a learning experience and go build another one. as you will be chasing your tail while it continues to crack and need work over and over again.

 

o wait, i think u guys got the wrong impression. i didn't fab the manifold myself, i bought it from hermsfab. he used to be a reputable biz on here, but haven't heard from him in awhilee, and his site has since gone down as well, so i'm pretty sure he went outta biz lmao.
i was simply repairing the crack that formed.

pretty sure it's SS, sch 10.

 

Then chuck it it's done. Get a new one. really the only logical way to go. not worth messing with it all the time.

 

yea that's what i figured *frown*

i guess this is my incentive/motivation to start my built G22 w/ a ramhorn and GT35 *mwaahahahaha*

 

to properly repair a crack, you need to drill a hole through the material at all ends (if there are more than 2) of the crack to prevent it from coming back or spreading further. if this were aluminum, you would have to completely remove the crack and all the oxidization by grinding it out completely, otherwise it will just come back.

 

ss is almost as picky as al...

if it was mine, i would take a cutting wheel, cut all the way through the crack... drill the holes at each end, and get a wire brush, bevel the pipes with a burr bit, brush it really good, then brush it again with some acetone.. then weld it with Stainless wire! you are wasting your time trying to fix it with mild steel..