Is JB Weld a hole filler or a real metal replacement?

Discussion in 'Motorized Bicycle Welding, Fabrication and Paintin' started by sofasurferlinux, Aug 8, 2009.

  1. sofasurferlinux

    sofasurferlinux New Member

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    I hear people talking about using JB Weld to fill holes before retapping. Or bonding metals together. What is JB Weld really good for? Is it a hole filler, similar to wood putty on wood? Or is it truely a substance that bonds to metal and is as tough as metal? I used to use furnace cement to fix the burned out fire pots on old pot belly stoves. Is it similar to furnace cement?
    What have you used it for?
     
  2. Humsuckler

    Humsuckler New Member

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    jb weld is not as strong as metal when used to bond to pieces of metal togeather, you can snap it with your hands, i tried it.

    i remember back a couple years ago in high school tho when i took the pins out of a buddies locker hinges and jb welded them back into place with a good load in his lock. didnt get it opened up for over a week and when he finally did he bent the door all to **** haha

    its good for fixin up threads thats right, and i have hered it used a couple times to repair chain smacked crankcases in dirtbikes. im not too sure if its as good as furnace cement tho, i have never hered of that.

    jb weld makes wicked bombproof locktite too if you need something to never move again
     
  3. sofasurferlinux

    sofasurferlinux New Member

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    Well, if anyones interested, furnace cement is unbelievably hard stuff. Don't know about its bonding limits but like I said it is good enough to seal up a completely burned out fire pot (where the hot coals are) in a furnace. Thus, the name "furnace cement". And when shaping it, a high speed grinder is barely a match for it. Takes forever to grind it. Probably comparable to the hardness of the rear sproket when I had to enlarge to hole.
    Anyone ever used it?
     
  4. Saddletramp1200

    Saddletramp1200 Custom MB Buiilder

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    Sounds like fun. Where can I get furnace cement?
     
  5. sofasurferlinux

    sofasurferlinux New Member

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    I used to buy it at the hardware store. Also called "retort cement" I think.
     
  6. 2door

    2door Moderator
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    I know a lot of the guys swear by JB but I'm not a fan. If I want a true metalized epoxy based adhesive/filler I use Devcon. They make several different products specially formulated for repairs on steel, aluminum and other metals. They have some high temp stuff called 'Liquid Titanium' that I saw used successfully to reattach a broken cast iron flange on a steam boiler. I've used both,the 'Liquid Steel' and 'Liquid Aluminum' with good results. You'll pay a lot more than the hardware store JB but like they say; "You get what you pay for".
    Tom
     
  7. tyrslider

    tyrslider New Member

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    I can echo what others have stated and add a bit. i like devcon better but jb is good stuff. They are as hard as metal but not as tough i.e brittle. Their effectiveness has everything to do w/ surface preparation as well as application.

    I've repaired gas tanks, crankcases, made molds/ fixtures for machining, tapped and machined them. They can be very useful!
     

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