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  1. #1
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    Repairing bonded titanium frame

    Hello everyone,

    I recently purchased an older Miyata bonded Ti frame (with aluminum "lugs") on eBay. I just received it today and was dismayed to see that the tubing has come out of the lugs on the headtube downtube joint and the seat tube seatstay lug.

    1) can I just JBWeld it? If not, what glue to use?
    2) is there some way to permanently fix this and prevent it from happening again?
    3) if I were to have a framebuilder reglue it and repair it, what should I expect to pay?

    I'm hoping to have this info in hand before I email the seller.

    Thanks,
    Richard

  2. #2
    Senior Member zonatandem's Avatar
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    A qualified framebuilder could fix it. No idea what it would cost.
    Heat expansion between Ti and alu has caused many such separations. Ti and alu expand at different rates.
    Usually a builder will insert and agent/barrier between the two metals and then do the 'glueing.'
    No, you cannot JB/epoxy it or do it yourself.
    Would demand refund on your purchase price, unless you were informed ahead of time of the separated state of the tubes.
    Good luck.

  3. #3
    Senior Member Nessism's Avatar
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    Look up HH Racing and talk to them. http://www.hhracinggroup.com/ They have lots of experience in fixing bonded frames.
    Becareful buying/selling bike parts on-line. I learned the hard way. :(

    Good/Bad Trader Listing

  4. #4
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    Did it come completely out of each socket? If so, you can get some good epoxy to go in and glue it back, if not and it just wiggles alittle and loose, you need some real thin epoxy to run it in, harder to do that.

  5. #5
    I give up! cujet's Avatar
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    Hysol brand epoxies are typically used as aircraft structural epoxies. Some of them have qualities you will find perfect for your application. They are so good that use on laminated aircraft wing spars (yes, the wing's load carrying part) results in large increases in overall strength and in some cases, survivability.

    I have seen applications between aluminum and Ti with Hysol. However, I cannot remember the part number. I think I have some of this very stuff left over from aircraft structural repairs in my shop. 9309.3NA comes to mind, but......

    Chris
    If it doesn't burn fossil fuel, I don't like it.

  6. #6
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    The hysol epoxys I use are 9320(blue) or 9394(grey)

  7. #7
    I give up! cujet's Avatar
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    One word of caution about Hysol. Often times it does not reach full strength right away. It cures rather quickly, 12-24 hours, but the full strength comes after a much longer time. In fact, it can often be pulled apart (with great effort) after 1 day. But after 1 week here in hot and sunny South Florida, it is much stronger.

    Chris
    If it doesn't burn fossil fuel, I don't like it.

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