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Tech Talk => Info Articles => Product Evaluations => Topic started by: Oz on November 10, 2008, 12:49 PM

Title: JB Weld Crack Repair/Sealant
Post by: Oz on November 10, 2008, 12:49 PM
Rating:  AAAAA+
 
Used for all types of crack repairs on many materials, particularly metal and plastic.  Product has been around almost as long as Ed Brady and takes abuse equally well.
 
Positives:
 
Dries very, very hard!  Takes 15 hours to cure, but if you put a shop lamp (especailly the kind with the silver "cone" shade) over the repair area, it will set solid in about 10 minutes and cure in about 4 -5 hours.  Let it cool and finish curing another 2 or 3 hours just to be sure.  Withstands heat up to 600 degrees F and can be used to seal leaks for any type of automotive fluid (not recommended for brake line repair).
 
Negatives:  None known.
 
Evaluation:
 
Repaired 3/16" hole and crack in transmission pan.  Stopped leak, holds-up to daily use.

Repaired rear view mirror which was bustedo off in a ragged break line on a Chevy.  It was the only thing that would hold white metal (porous) and hold it firm.  Filed, sanded & painted... couldn't tell it was ever damaged.
 
There have been many recommendations on this product describing how it saved tons of time and costly repairs.  See "JB Weld" in the Message Search for Rich Shaw's successful engine block repair!
 
Sources:
 
Available at most major retailers and auto part stores.  Cost around $5
Title: Re: JB Weld Crack Repair/Sealant
Post by: bigern on March 17, 2009, 08:11 AM
jb weld is realy good i used it to hold the magnets on a magneto on a briggs and statton engine never come off yet.
Title: Re: JB Weld Crack Repair/Sealant
Post by: ibdilbert01 on August 13, 2009, 06:53 PM
My guess is the stuff holds up pretty good around gas.   As two years ago I glued a cracked carburetor bowl on my generator as a quick fix, and its still holding solid.   
Title: Re: JB Weld Crack Repair/Sealant
Post by: Froggy1936 on September 20, 2009, 10:51 AM
I used it to repair a broken hinge on a foot operated trash can lid  over a year ago still works fine had to drill new hole for operating rod  Frank :)ThmbUp
Title: Re: JB Weld Crack Repair/Sealant
Post by: GONMAD on August 09, 2012, 04:09 PM
MARINE TEX is another substance used for the same purpose. It can be drilled & tapped for repairing stripped bolt holes as well as fixing cracks These substances will NOT hold up to exhaust temperatures OK on just about everything else. One more thing, Marine Tex comes in two types, gray & white if color is required. Just my 2 cents worth.   C YA! GONMAD
Title: Re: JB Weld Crack Repair/Sealant
Post by: ClydesdaleKevin on August 10, 2012, 07:22 AM
I prefer the Marine Tex as well, which is what I fixed my fridge door hinge with.

They make a marine Epoxy putty, and they also make Rapid Set epoxy putty, which comes in 2 tubes like JB Weld, and is WAY stronger than JB.  The regular epoxy putty does come in white or grey, and you mold it like clay after mixing in the clear vial of hardener.  The Rapid Set dries dark grey with a consistency before curing very similar to JB.  Both excellent products and are now the only ones I'll buy.  You can get them in any boating store, and usually at any hardware store in coastal areas.

Kev
Title: Re: JB Weld Crack Repair/Sealant
Post by: cosmic on August 10, 2012, 10:48 AM
Well as a welder and owning my own business as a mobile welder, I used JB weld many times in my life. I love the product for certain jobs.
That being said I use it where heat, warpage, white metal (Chinese shoot) could be an issue. works great on gas leaks, but then again so does epoxy glue.
I would not recommend it for anything needing strength. its great for holding small delicate things and stopping leaks.
Don't try to repair your frame rails with it. LOL.
Title: Re: JB Weld Crack Repair/Sealant
Post by: moonlitcoyote on September 20, 2012, 11:03 PM
Tried JB Weld on a leaking gas line and it held for about 10 minutes. Was not happy with it.  N:(
Title: Re: JB Weld Crack Repair/Sealant
Post by: Gary Eddy on April 09, 2013, 07:23 PM
12 horse law mower engine threw a rod out the side of the block. Installed a new piston and rod, JB Welded the piece of the block back on.  Still cutting 2 acres of grass 6 years later.  ;)  Yea, it is good stuff.
Title: Re: JB Weld Crack Repair/Sealant
Post by: cosmic on December 09, 2013, 09:17 PM
The new gas with ethanol (% corn gas) will eat through jb weld and almost all other forms of epoxy glue.
The recommended choice for use on ethanol fuel is Miller/ Stevenson 907 (this is my conclusion after testing many brands)
I called the manufacture and they sent me a free sample kit. no charge. not even shipping. In todays times you don't see that very often. great company and my carb works wonderful again. :)ThmbUp
Title: Re: JB Weld Crack Repair/Sealant
Post by: Oz on December 12, 2013, 02:56 PM
Might want to make that a new product evaluation topic since it's a different one and would make it more prominent.
 
 :)