Re-repair a cracked block

[F14CRAZY]

So, the previous owner of my 3.0L didn't winterize and the water jacket of the block cracked and he repaired it with JB Weld (he didn't say this but I can look under the manifold and see the repair).

The problem is that the repair seems to be letting water leak out of the water jacket and into the hull (no oil contamination). It isn't awful but it's a good trickle and will leave a decent amount of water in the bilge after a weekend.

I would like to remove the manifold and fix this. I understand that JB Weld generally works ok for cracked water jackets if I properly prep the surface by grinding a little bit of a V into the crack and drilling out the ends of the crack to keep it from spreading.

I got thinking though...I'm not a pro but I do have a Lincoln arc welder and I'm half-decent at it. Can't I just weld the repair instead of using epoxy? I'd do the same by grinding in a V and drilling the ends but wouldn't it be a better fix?

Thanks guys

 

[mkast]

Re: Re-repair a cracked block

Have you ever welded cast iron?

 

[F14CRAZY]

Re: Re-repair a cracked block

LOL I don't know how I forgot about that...no, I haven't...

JB Weld it is!

 

[lowkee]

Re: Re-repair a cracked block

You can always buy a cheap set of cast iron pans and practice. I have never either, so someone may step up and say it can't be done with an arc welder, who knows. It'd be a shame to kill a nice cast iron pan (I love my set), but if you can get a good bead on that, you may be in a good position to try your block.

 

[rbh]

Re: Re-repair a cracked block

do not drill out the ends of the cracks unless you are willing to tap and put plugs in!
rob

 

[jam1ej20]

Re: Re-repair a cracked block

Just bite the bullet and get a new manifold. You'll spend more time and money than it's worth trying to fix a crack in cast iron.

 

[dontask]

Re: Re-repair a cracked block

If you have never welded on cast metals, practice before you destroy the unit your trying to repair. And even after numerous hours practicing realize that what you practiced on may not stress and distort like the unit you want to repair. I have arc welded many many hours. I was very good at welding regular metals but----cast metals are very different. I did not get good results all the time. The metal can crack very easily AFTER you lay down a perfect bead due to lack of heating before and after (controlled cooling). You will also need to use a special rod designed for the cast metal your welding, check out nickel content rod. This nickel rod comes in various nickel ($$$$) content percentages. Does your welding machine have reverse polarity? This one welding job might be worth it to take it to a shop that specializes in cast welding. good luck

 

[dontask]

Re: Re-repair a cracked block

Just bite the bullet and get a new manifold. You'll spend more time and money than it's worth trying to fix a crack in cast iron.

Ditto

 

[bruceb58]

Re: Re-repair a cracked block

Just bite the bullet and get a new manifold. You'll spend more time and money than it's worth trying to fix a crack in cast iron.

He is talking about his block...not the manifolds.

 

[Susquehanna Squid]

Re: Re-repair a cracked block

I just went through the same thing. I pulled the manifold removed the 10 pounds of JB (that the previous owner applied) and cleaned the heck out of it. I installed a new gasket and re-JB Welded it. I had 2-6 inch cracks, one in the block and one in the manifold and I have not had 1 drop of water leak out since. I did not drill the ends of the cracks but we did clean them (with brake cleaner)and used a pneumatic tool with a soft grind/polish wheel. I let it sit for 3 days after I JB'd it again. Try this first, it cost me $20 for the gasket and the JB and a case of Bud to my friend because we used his tools etc. (he is a mechanic). Oh and by the way, mine leaked so bad that I had to run the bilge any time the motor was running because water was cascading down the side of it! Good luck!

 

[nibs75]

Re: Re-repair a cracked block

the fix still holding?