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  1. #41
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    Quote Originally Posted by EPAIII View Post
    Just a thought and not to argue against the epoxy idea, but wouldn't some LocTite on those bolts help? And perhaps a bit more torque: put a pipe on the wrench.
    They're using a Hy Tork on them. Depending on the model it might wring off a 2 inch bolt.
    T

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    Quote Originally Posted by digger doug View Post
    The stuff is kicking off in 5 minutes presently, heat will just cause to go faster.
    Which was a puzzle to me because anyone who has used epoxy at low temps knows it doesn't work. It kicked off in five minutes at 30* ? Was that Fahrenheit or Centigrade ?

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    Could you heat the bolts to give some growth before you tighten them down as they cool they should become tighter?


    Sent from my iPhone using Tapatalk Pro

  4. #44
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    Quote Originally Posted by EmanuelGoldstein View Post
    Which was a puzzle to me because anyone who has used epoxy at low temps knows it doesn't work. It kicked off in five minutes at 30* ? Was that Fahrenheit or Centigrade ?
    A puzzle to you? Imagine the shock and defeat I felt when a $300 hardened glob of epoxy falls out of the bucket.

    My user name is Farmer Phil and I live in Kentucky, it should be assumed I was using Fahrenheit.

    The company representative contacted me back this evening, albeit after we decided to pull the trigger but they did call back and presented me with a favorable response when our method was described.

    I'll explain what we did later this weekend and address some comments as well.

    Thanks to all who offered guidance and observations, a lot of very helpful information. I never really thought that I'd have an opportunity to be involved on the forum so for my first time I feel good about it.

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    Not surprised that it kicked over so quickly if you had it in a bucket. When epoxy crosslinks(cures) it gives off heat (exothermic). When that much material all in a bucket your are lucky it didn't go faster. Masses like that I have seen boil from the exotherm.

    Tom

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  7. #46
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    Quote Originally Posted by TDegenhart View Post
    Not surprised that it kicked over so quickly if you had it in a bucket. When epoxy crosslinks(cures) it gives off heat (exothermic). When that much material all in a bucket your are lucky it didn't go faster. Masses like that I have seen boil from the exotherm.

    Tom
    Yes, I really accelerated my understanding of mixing bulk epoxy yesterday.

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    Quote Originally Posted by TDegenhart View Post
    Not surprised that it kicked over so quickly if you had it in a bucket. When epoxy crosslinks(cures) it gives off heat (exothermic). When that much material all in a bucket your are lucky it didn't go faster. Masses like that I have seen boil from the exotherm.

    Tom
    general RTC epoxies are good for up to 10-12mm thick layers (manufacturer should supply customer with this information), if the product requires greater thickness, then slow hardeners are used, or you pour or do the layup in layers, let the previous layer cure, then rough sand with 60-80 grit and apply next layer

    next thing probably doesn't apply in this case, but when I needed to extend pot life of a larger batch, I would pour the mix into a tray like container, so it stays in a thin layer helping it stay cool, since there is basically nothing there to evaporate from the mix, this causes no performance issues of the final product

    one more note, most epoxies are sensitive to moisture, so if for instance, propane torches or space heaters are used in a confined space, you can expect some water condensation on colder metal surfaces, make sure the surfaces are dry before applying the epoxy

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    The other other reason I didn't think this would work is that epoxies are brittle resins and will not take pounding. An associated failure mode is fretting which is micro movement usually in elastic range that abrades away high points. The abrasion slowly relaxes the stress. The only solution that I think will work is some sort of elastic cushion, perhaps urethane.

    Are the nuts loosening or is the fretting? If the nuts are loosening, double nutting may help. Lock washers probably will not work as they create points of high stress.

    Tom

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    Quote Originally Posted by TDegenhart View Post
    Not surprised that it kicked over so quickly if you had it in a bucket. When epoxy crosslinks(cures) it gives off heat (exothermic). When that much material all in a bucket your are lucky it didn't go faster. Masses like that I have seen boil from the exotherm.

    Tom
    Ha! Years ago I worked for the maintenance department of an organization that access to a lot of resources, but decent engineering wasn't one of them. The project one day was to drill some concrete curbs and pot rebar in the holes so the curbs could be extended upward to form low walls. After the ironworkers drilled their holes and cut their rebar, they went over to the motor re-wind shop to beg some epoxy, any kind will do. They came back with a gallon kit of some water white white stuff that was meant for brushing on motor windings. They proceeded to dump both parts in a pail, and swish it around with a stick. In twenty seconds it started to boil, and the guy dropped the pail. In another twenty seconds it started to smoke. At a minute the whole pail was hard, and twenty or thirty seconds later the solid block cracked in half from thermal expansion.

    The second kit they bummed they spent the rest of the day mixing one little pleated paper cup at a time.

    Dennis

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  13. #50
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    Your in a pinch to get the metal muncher bolted back down. If you still have enough metal to metal contact it may go. Can you add piers and brackets in downtime. Anything you do needs cure time. They have some pretty good concrete epoxy's.
    Their failure to retorque is costly but there seems to be an engineering failure here.
    A TV show modern marvel's showed one of these machines. Massive metal. I can se it trying to self distruct.

    People have been killed mixing to much epoxy in one batch.


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