JB Weld on a cracked exhaust manifold

[loglat]

Anyone ever tried this? I'm wondering how well it will work. Short of pulling the engine and replacing the exhaust, I'm looking for a quick but effective (at least reasonably so) way to cut down on the noise and smell of my cracked exhaust manifold. Any thoughts, or other possible remedies? Thanks!
-Loglat

[fordman]

tack weld it while it is on the truck and keep tack welding it until the crack is gone. that is what my dad did to mine he used ncikel rod for wwelding cast iron it worked fine. he also took it off and welded the backside also. but if you dont want to remove yours right now. you could just weld the front of it. unless the back isnt broken.

[brandon.k]

I tried it years ago when i had to put a junk yard 289 in it to just get around. It didnt work. I cleaned the crack really well and let the J.B. Weld set for 24 hours before i fired it up. It was quiet for a couple of min. but just burned right off.

[OldRedFord]

Check this out if you want to try to weld it. Good info.

http://lincolnelectric.com/knowledge/ar ... reheat.asp


This might work...your local auto parts store should have it.

http://www.amazon.com/o/ASIN/B000ALBZMG ... HMHQ9QTDR2

Or get some furnace cement.

[loglat]

That permatex looks like it should get the job done. I worry that without someone who really knows what theyre doing, i could end up worse off than i started if I try to weld it.

[DuckRyder]

Then there is this:

http://www.por15.com/FIRE-SEAL-2000/productinfo/FS2/

[dustman_stx]

Good luck repairing a crack on a manifold. Especially one that's old and has heat cycled who knows how many times. I found a Chinese repro on ebay for less than $50, brand new. It worked fine, and has been for a year now.

[Dragon]

I have welded a lot of cast iron but only one manifold. We ran the engine to get the manifold hot then welded the visible side. After wards we popped it in the oven and got it to 450 then welded the back side.

[eggman918]

Cast iron must be pre heated to 350 deg F. the crack needs to be stop drilled, nickle rod will work it is nessary to only run about 1" bead at a time then peen bead with chipping hammer.
If you cant reach the back side of crack vee the crack with grinder3/4 the way through,keep it warm while welding and let it cool slowly.If the iron is not sound It will not work
it will just disintegrate when you strike an arc .It is not difficult to do just time consuming.You will probably need to surface it when finished.

[hazelnut]

Years ago i had a 8N ford with a cracked manifold i used epoxy putty, its held up for 15 years now. i sold the tractor to my brother in law about 6 years ago and asked him about 2 months ago if the putty was still holding. he said its still on there working like a champ. the epoxy putty i used is made by Oatey, the same company that makes PVC glue and i bought it at ferguson enterprizes the plumbing supply chain. it comes in a tube and you cut off how much you need and squeezeing and folding to mix the putty and when it gets worm in your hand it ready to apply.

[Skifu]

I had a 2 in split on the plastic end tank of my radiator,I removed the tank from the rad,and cleaned it thoroughly,I used epoxy mil 2 part which is like JB weld,and it didnt hold for no time,all its got on is about 16 psi right?it wouldnt even hold on a radiator leak,I doubt it will hold on a manifold.

[george worley]

I used that expoxy putty that Hazelnut is talking about to patch a hole that got punched in the bottom of a gas tank on a old Firebird. It worked great. It was supposed to be a temporary fix but it never leaked and lasted over a year.then we junked it out. I keep a tube on hand. I got mine at Home Depot.

[hotrodfeguy]

Ford man and Dragon are right, But I have MIG/wirefeeded them also and had them hold. To be honest I think they expand at a higher rate than the head and causes them to stress crack when they contract faster than the head.

[Dragon]

I had a 2 in split on the plastic end tank of my radiator,I removed the tank from the rad,and cleaned it thoroughly,I used epoxy mil 2 part which is like JB weld,and it didnt hold for no time,all its got on is about 16 psi right?it wouldnt even hold on a radiator leak,I doubt it will hold on a manifold.

You keep talking about this plastic crossflow radiator that has nothing to do with our year trucks. What works on Iron does not work on plastic and vice versa.