Exhaust manifold crack - braze or ??

[Reyer Farms]

I have done brazing like this, it would be my method of choice for repair. It needs to be done correctly and I have found it is as much feel as science. All joining processes are about heat control. I do not own a welding tip, I have repaired cast items to a ridged hydraulic line ( on tractor in hay field) with my cutting torch. I am not saying it is the best or you don't need just that it can be. For the record the fix on the line held until end of the season and he took it to shop for replacement. Good luck, Lincoln electric publishes the procedural handbook of arc welding. They discuss welding cast and the different types. It is invaluable to anyone that welds.
Jody

 

[Shield Arc]

This is a very good book by Lincoln.

 

[1fastbob]

Get a used manifold and install it. In my opinion this one is not repairable and not worth the trouble.

 

[Reyer Farms]

This is a very good book by Lincoln.

Second that motion! The older the copyright the better. I also have new lessons in arc welding. Great book for honing skill in positions and technique. Good books. I also enjoy welding tips and tricks website. I am not that Jody btw. Welding web is good but sometimes the ego is more than I can bear. Books are reliable the same answer to the question every time.

 

[LD1]

If it were mine, Id go the epoxy route

The only good way to weld/braze is with it out of the vehicle. And with careful temperature control as already metioned.

And I am sure that running your stove @ 500 degrees for 24 hours isnt going to be cheap.

I agree that it needs fixed. Especially with the location. (Have you noticed a drop in fuel economy?) cause if that 02 sensor is picking up oxygen being sucked in from that crack (and most likely it is), it will think it is running lean and dump more fuel. You will actually be running rich just to make that 02 sensor see a normal condition.

And since it isnt really a structural concern, all you really need to do is just seal the crack. I would try something like this CarGo/3 oz. ThermoSteel High-Temp metal repair jar (18003) | Epoxy Compound | AutoZone.com

 

[yomax4]

I have enjoyed the best repairs on manifolds with a Spray Powder Torch.. Never had one re-crack. I have had some old junk cast just melt away while heating but usually spray powder works perfectly. The nice thing about it is you are only heating it burgandy red instead of blasting it with 20 volts or 100 amps. Like anything, there are a few cool tricks. If you decide to do it this way, let me know. It's certainly not the least expensive way how ever. I agree with above, For Mig or Strick I would use 309LHS or 312 Stoody Versalloy is a 312 stick.

 

[dstig1]

Wow -lots of good info here. I guess I did leave out a key piece of info - I don't want to pull this from the car. Given age and miles and corrosion, I will surely snap studs off. If I'm going to pull it, I'd probably just replace it. I've looked for used ones, and they seem to have the same crack, so that doesn't seem like a good option. So a fix would need to happen in place...which makes it extra fun. Since you can't do the usual slow cool down of the part by burying it in sand, I figured brazing might work better as it is lower heat

Gas mileage has been rock steady 30-35mpg. I suspect this happened about 3-4 yrs ago, but you can't see it due to the heat shield blocking the view. Back a few years I started to hear a whistle in very cold weather that would go away when it warmed up, and I now suspect this is/was the cause as I never found anything else. I only found it because the O2 sensor died and I had to pull the heat shield to get at it.

The high temp repair goop sounds like a very good idea. I have to say I am quite skeptical that any glue/adhesive can handle the temps, but that stuff does seem to be rated high enough. Never heard of it. I'll look into that stuff a bit more.

Thanks guys!

 

[LD1]

Let us know what you decide.

I think about the only option is going to be some type of "glue" IE cold weld. Cause if you try to weld or braze ON the car...who knows what other damage you may cause.

 

[dstig1]

Cause if you try to weld or braze ON the car...who knows what other damage you may cause.

C'mon! What could POSSIBLY go wrong?!?!:laughing: :fiery: :laughing:

 

[ruffdog]

In my opinion this one is not repairable and not worth the trouble.

I agree.....a honda with 200k is not worth it...........