on a cast iron manifold to fix a crack before?

 

i'm no rocket scientist, but it will most likely melt.

 

yup, just read that on their site.

 

u need to heat up the cast +weld

 

try ducktape

 

u can try looking at my thread i used JB weld on my block and JB weld works wonders.. many told me its not going to hold...
https://honda-tech.com/zerothread/1598334

 

JB weld on the manifold will not work. I put it on a header a while back since it was leaking bad, and after the header heated up and I took it for a long spin the jbweld just flaked off. the heat generated is too hot.

 

yeah, the exhaust mani gets too hot for jb weld, so it won't work. i took the manifold to a welding shop today and they said they can weld it with no problems.

i just didn't know if they could do it cause the manifold is cast iron.

 

I used JB Weld on my downpipe once to fill some leaks from the fact that I cant weld worth ****.. I had to reapply the jbweld like every 2-3 weeks and I didnt drive the car everyday..

Just pile it on thick and plan to add more often.. Or just get it fixed and be done with it..