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Welding external block cracks ?

Old 08-15-2002, 11:45 PM
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Location: St. Petersburg, FL
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Question Welding external block cracks ?

Fellas, what are the pro's and con's of brazing or welding this external water jacket crack? Don't be shy!

As you can tell from the pic. my buddies '87 OMC 5.0L block didn't fare too well in it's last Wyoming winter. The engine's pulled, we're contemplating brazing the crack and pressure testing. If she passes the pressure test, then well put her back in, that if it's a feasible option. Otherwise, it's a new bare or short block, alot more work and a few more $$$$....

Lemme know what ya think...
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Old 08-15-2002, 11:48 PM
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Unhappy block crack

never seen it done sucsesfully a 5.0 bare block is relitivly cheep good luck. Charlie
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Old 08-16-2002, 12:02 AM
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I,ve never admitted to this before but 4 years ago a friend brought his boat over with a crack in the block that looked just like yours and it was also from not winterizing properly. It was an older boat and he said he was going to junk it if I couldn't fix it real cheap. I used a small dremel to grind the rough burrs off the exposed section of metal that popped out and then banged it back into place with a hammer. I then lathered on a generous portion of J-B weld. He's still driving this boat around, happy as a clam !!

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Old 08-16-2002, 12:06 AM
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I am with Bo. Go with the JB weld if he is looking to go cheap. It is worth a try. I would think that getting the block hot enough to weld properly you are likely to either crack it more or cause the block to be redecked and what not.

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Old 08-16-2002, 12:18 AM
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welding cast iron is a little tricky, but for a real welder, its not to bad, if the boat is a keeper, replace the block, if not check out your options
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Old 08-16-2002, 12:27 AM
Join Date: May 2002
Location: Warrington, PA
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i recently had this same problem
the previous owner of my boat didn't winterize it properly and i got stuck with the repercussions
he had the crack welded and needless to say it cracked again. i pulled the motor and took it to my engine builder and he said don't even bother trying to save this block, its junk. BTW my crack wasn't nearly as bad as your buds.
good luck

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Old 08-16-2002, 05:18 AM
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I am with Bo. It is worth a try, I have a buddy that did this and the boat is still running strong. what are you out for trying besides alittle time.
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Old 08-16-2002, 06:54 AM
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I`ve used JB Weld on cracked blocks before and it always worked for me too!
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Old 08-16-2002, 08:15 AM
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I have seen the JB weld thing done myself,,,, just be sure to stop drill holes at the ends of the crakes to relieve them.
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Old 08-16-2002, 08:35 AM
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Better pull the intake and look inside. Drill the ends of the cracks, wire wheel and clean with alcohol (or drink it), weld up what you can and cover with JB Weld. Don't run it hard until the temps come up and stabilize. Seen several JB boats run for years. Probably get by with it if no cracks on the inside. If you go this route verify bilge pump is in working order and carry a topsider oil change and some oil and filter on board. You may want to change the T-stat as well.

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