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I once repaired a radiator once with JB weld and it worked. But before you do here's some advice first locate the crack, drill a very small hole in the radiator at each end of the crack. This will prevent the crack from splitting and getting larger. Second make sure it is very clean in that area that you will be appling JB weld. Use some sand paper on it so it will give it a better bound. JB weld does work well for that perticular application.


A few more tips:

my '97 Camry recently developed a hairline crack across the top of the radiator, so i called a buddy of mine who's been a diesel mechanic for 10+ years, and he said he's seen great results using JB Weld on plastic radiators. his recommended tips were:

- 1st (and VERY important), allow your vehicle to cool overnight to ensure the radiator and engine is COMPLETELY cold as can be before beginning the repair.

- distress/score the area around & including the crack with some steel wool or sandpaper. you could use a Dremel or something of the sort, but you must be extra careful to not dig too deep (as it would weaken the radiator even more-so.

- use some brake cleaner and shop towels to clean the area around & including the crack VERY well after you score it.

- drill 1 small (and i emphasize SMALL) hole at each end of the crack (2 holes in total - 1 at each end) to "terminate" the crack so that it won't crack any further.

- mix up the JB Weld so that it's nice and tacky (more so on the thick side).

- apply the JB Weld thoroughly (but not TOO thick) to cover all of the crack and the 2 small holes you drilled at each end.

- allow AT LEAST 24 hours for the JB Weld to dry & cure thoroughly. the colder and/or wetter (humidty, rain in the air, etc...) the longer you need to wait. if you can wait 48 hours, you can rest assured that it should be cured thoroughly (again...make sure the JB Weld stays DRY).

- again, DO NOT START the engine for any reason during this 24-48 curing time. it will heat up the radiator and put internal pressure/stress on the repair which WILL prevent it from curing properly.

i hadn't thought about inserting mesh or fiberglass screen into the JB Weld when it's applied, but it sounds like it would definitely make the repair hold up better. GREAT idea!!

I'm going to attempt this repair tomorrow (Friday, 1st October) and then not drive the car for a couple days. here's to hoping!! :)

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โˆ™ 2011-09-12 23:06:16
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Q: How do you use JB Weld to repair a 1-inch crack in your radiator?
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