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Thread: Shelf life of epoxy

  1. #1
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    Default Shelf life of epoxy

    How long will unopened epoxy last? I bought some two or three years ago and am finally getting to the point of needing it. Should I trash it and buy new? I don't want to screw things up by using bad glue.

  2. #2
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    Default Re: Shelf life of epoxy

    I have kept epoxy for years while using it in small batches. The same with polyester resin. Mix a small batch and check for set and cure time. If you insist on trashing it I can dispose of it for you.

  3. #3
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    Default Re: Shelf life of epoxy

    Dave Carnell says a long shelf life.
    Steve Martinsen

  4. #4
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    Default Re: Shelf life of epoxy

    I may have jumped the gun on this. The epoxy in question seems to have disappeared into the inventory somewhere. It was sitting on the workbench but I am redoing the shop and the bench is no longer there, neither is the epoxy. I only need a small amount so buying new won't break the bank. Someday I will get things organised, maybe.

  5. #5
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    pittsfield nh usa
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    Default Re: Shelf life of epoxy

    longest I have heard was 28 years on the shelf - might have been open units
    paul-progressive epoxy polymers inc

  6. #6
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    Default Re: Shelf life of epoxy

    I "lost" a kit of T-88 that I ordered a bit ahead of schedule....12 years later I was building a "dink" or fishing boat for BIL......I moved something and found it....tried it, seemed to work, used it...painted boat.....boat has been repainted 2-3 times and still solid after nearly 40 years.
    Wakan Tanka Kici Un
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    Fighting Illegal immigration since 1492....
    Live your life so that whenever you lose, you're ahead."
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  7. #7
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    Brooksville, Florida, USA
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    Default Re: Shelf life of epoxy

    Failure mode for epoxies is an increase in viscosity with eventual solidification. Or so the theory goes. I have 30+ year old epoxy that still kicks off just fine.

    /// Frank ///

  8. #8
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    Wellesley, MA USA
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    Default Re: Shelf life of epoxy

    If the epoxy is exposed to cold, it'll crystalize. Gentle warming will dissolve the crystals.
    Some hardeners i've used get darker in color, but still work OK.

  9. #9
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    Default Re: Shelf life of epoxy

    I just used some ancient opened West 105 resin that looked perfect--clear as water. Since I didn't have any West hardener I ran a test with some MAS slow hardener I had on hand. The hardener pump broke so I eye-balled a 2 to 1 mix and the stuff held solid wood and marine plywood in a death grip. To give it a real tough test I used the mix without thickening it.

    I am not sure how old the West resin was. I probably bought it when I fabricated the pilot house roof on my Gazelle...which would have been around 1995. But it might have been even older than that because I think I built that out of polyester and 'glass (no wood).
    Goat Island Skiff and Simmons Sea Skiff construction photos here:

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    and here:

    http://www.flickr.com/photos/37973275@N03/

    "All kings are not the same."

  10. #10
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    Lewiston, Maine
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    Default Re: Shelf life of epoxy

    Mostly all epoxy sold is made by only 2 or 3 manufacturers.

    At least the base material.

    The epoxy retailers spec out the formulation for whatthey wish to sell and may add some various chemicals in it form what I understand.

    Epoxy stored ina cold garage will crystalize.

    Crystalized epoxy in an epoxy pump throws off metering.

    Placing gallon jug of epoxy in a 5 gallon bucket of hot water will usually melt it back to liquid.

    You may have to replace hot water a time or two.

    Keep changing out hot water until pumps no longer have crystals in them.

    Every time I have had pump problems it has been resolved by melting the crystals in the pump.

  11. #11
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    Default Re: Shelf life of epoxy

    ...you met the guy who invented it? ...a nazi?/ originally made to build up french runways for heavy german bombers?

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