Something better than muffler cement?

Discussion in 'Technical Repair' started by MrChips, Mar 13, 2017.

  1. MrChips

    Thread Starter Moderator

    Oct 2, 2009
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    Would JB Weld work on repairing automotive exhaust?
    I have been constantly fixing the exhaust on a 2003 Toyota Echo. I have two U-clamps on tubing to join existing exhaust piping. Regular muffler cement to fill the gaps doesn't hold after awhile.
     
  2. #12

    Expert

    Nov 30, 2010
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    I have my doubts. hard=brittle. If you are in the hot zone, the exhaust pipe will wiggle out from under the epoxy.
     
  3. wayneh

    Expert

    Sep 9, 2010
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    My gut is that JBWeld is not a great choice for that because of the flexing and temperature changes. I've had luck with a tape + goop system, where you apply the goop as you wrap a tape around the area. It's been too long ago for me to remember the details, except I remember that it did hold for quite a long time.
     
  4. MrAl

    AAC Fanatic!

    Jun 17, 2014
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    Hi,

    It might work if it is not located near the exhaust manifold or near a cat converter, but too close and i would not bet on it. I used it in two places for the SAS system and that is coupled to the exhaust system but i dont think any of that handles exhaust gases. The exhaust manifold even on a four cylinder engine gets over 900 degrees F and the cat converter must get very hot too. Maybe the tail pipe is cooler.

    Most stuff does not work on the exhaust pipes but there is one thing that does work, at least it did on my old four cylinder car for one exhaust pipe that was about 2 feet from the exhaust manifold.
    That is a steel can like from vegetables cut down the side to form a round pipe with a slit on one side so it can be opened up. With the engine cool the can is opened up, placed over the leak, then two C clamps installed one on each end and tightened up. Before the C clamps are installed however a layer of Permatex Ultra Copper Gasket Maker is applied near the leak hole so that when the steel can squeezes the pipe it forms a gasket between the steel can and the old pipe. Once the C clamps are tightened, the stuff is given 24 hours to cure before starting the engine. That Permatex stuff is the highest temperature stuff i know of except for ceramic based stuff which is both expensive and probably brittle. None of the other Permatex gasket stuff is that high so that's the best choice, or at least it was as of circa year 2014 or so.
    The fix can last as long as a year or more. I used an aluminum beer can instead of steel once but the aluminum melts and the can deforms.
    Obviously there has to be good mechanical support for the pipes or else maybe use more than one steel can (one larger over one smaller) and more than two steel C clamps, and/or some extra steel wire hangers.
    Check once in a while for expansion of the clamps and retighten if needed.
     
    Last edited: Mar 13, 2017
  5. MrChips

    Thread Starter Moderator

    Oct 2, 2009
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    Thanks for all the tips.
    The joint is between the cat and muffler. I got a muffler section from the scrap yard and it is in good condition.
    The pipe end off the cat is going a bit soft (rusted). I might have to go all the way and replace it from the manifold. Problem is you can't find that section in the diy yards. They cut off the cat and sell it for the platinum and palladium.

    Either that or the whole cat and caboodle goes to the scrap yard. This little gem is running on borrowed time and doesn't want to give up.
    Four kids learned to drive on this little Echo (not all at the same time, maybe seven years apart).
     
  6. shortbus

    AAC Fanatic!

    Sep 30, 2009
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