JB Weld Cracked block? PERSONAL experience please.

tmh

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Anyways, I really want to hear from folks who have tried JB Weld on an external block crack and hear how well it worked or didn't work.

Please, save the "don't screw someone selling them a cracked block" replies. That is not my intention. I just want to hear from folks on the JB Weld "fix" as I know from searching Google that many have tried it, some I've read successfully, some a short-term bandaid.


EDIT by Don S
Keep it civil and stick to the question at hand.
 
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Bondo

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Re: JB Weld Cracked block? PERSONAL experience please.

Ayuh,......

As I mentioned before,......

It depends on the Crack,+ Where it Is........

JB Weld is Better than Welding,....
Matter of Fact,... Welds are usually slathered with the epoxy afterwards anyways.....

And there's Stitching with Pins,....
But again,..... It's All about the Crack,+ Where it Is....
 

Reel Poor

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Re: JB Weld Cracked block? PERSONAL experience please.

This is a copy and past from your other thread. This is what you posted and it will always be, "Can't be fixed with JB Weld".

POST #11 Today, 08:39 AM
tmh
Chief Petty Officer
Join Date: Aug 2006
Posts: 623

Re: Crap! Cracked block 305 Mercruiser - options?

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This is exactly why I asked the original question - to educate myself on whether this type of issue could be properly fixed for a reasonable cost. Looks like the experts have weighed in and it CAN'T. I'm fine with that and now I know.

Thanks to those who helped educate me on this subject. I really appreciate it.


EDIT AGAIN by Don S:
Like I mentioned earlier, this is NOT going to be a re-hash of the closed thread.
 
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billder62

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Re: JB Weld Cracked block? PERSONAL experience please.

Have had JB weld on my block for six yrs now , 350. hrs no problems at all , also mercuiser 5.0
 

bomar76

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Re: JB Weld Cracked block? PERSONAL experience please.

This is another one of those "keep asking the same question 'till I get the answer I want to hear" thread....
 
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Re: JB Weld Cracked block? PERSONAL experience please.

I have never usd JB weld in repairing any engine block. Suggest you gooole a product called Belzona, then link to their product called ceramic-r-steel. This product is the only cold repair recommended by Caterpillar for repair of their engines. This product is not cheap. But it is the best cold repair product I have found in 35 years of heavy equipment repair. Their website will give you contact information. Good luck on repairing cracked block just take your time and follow Belzona repair instructions
 

tmh

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Re: JB Weld Cracked block? PERSONAL experience please.

Thanks much to those who offered real-world experience. Anyone else use it? I'll check out that other product mentioned as well.

EDIT
by Don S.
I am going to say this one more (Last) time.
Settle down and keep your disruptive comments to yourselves EVERYONE!!!!!!.
 
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cheburashka

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Re: JB Weld Cracked block? PERSONAL experience please.

I'm going to weigh in with the "not what you want to hear" option again. I have a JB Welded block that served me well last season, and I expect it to serve me well again this season. The thing is, it's a 3.0 straight 4, and I only JB Welded it because it was already in the boat, and I didn't want to pull the whole engine to replace the block. On the 3.0, the cracks are in an external section of the water jacket which doesn't carry lifters or any other vital components. That just isn't true of the 5.0. Completely different animal.

It's possible that you can fix this with JB Weld. However, your engine is already pulled, and it's not a design that has had much success with JB Weld. What you've heard about JB Weld not working on V engines makes a lot of sense to me. Sure, you can try, but why? To repower a boat with a known defective engine? Doesn't sound like a good plan to me.

When you ask for advice, you may not like all the advice you get. You're asking pros how to do something the wrong way. Doesn't it stand to reason that they're going to tell you not to do it that way?

Why not put it up for sale as-is? Let someone else worry about whether to tear it down, or patch it up?
 

tmh

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Re: JB Weld Cracked block? PERSONAL experience please.

I'm going to weigh in with the "not what you want to hear" option again.

There is nothing I "don't want to hear", just looking for personal experience pro or con with JB Weld on an engine block. Sounds like your JB Weld repair is holding up well. Thanks for the distinction between your engine and mine with respect to such fixes.

So far, I've heard from one person who actually JB Welded an engine like mine and it's 5 years OK.
 

imported_TheMan

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Re: JB Weld Cracked block? PERSONAL experience please.

My V6 block had a crack in the water jacket.. As far as I can tell it is only an exterior crack, but I haven't dug far enough into it yet to verify. There is no water in the oil or any other problems though.

Anyway, I used a die grinder to blunt the crack trip and shape it out. I then used some aluminum filler epoxy (bit stronger than JB weld) and filled it in. Its been like this for 7 months now, but I've only run the engine probably 12 hours total. Seems to be holding up well, although I am keeping my eye out for another 4.3 block since I'm doing an upgrade anyways.
 
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