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My local hobby shop has one box of Z-Poxy Finishing Resin in stock. Not sure how much of it they sell or how long that one box has been on the shelf. It's nice to grab something here local......but should I be worried that it might be old? How long does this stuff last? Is there any kind of mfg date on the box? Thanks.

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Formerly known as Adaboy.......

I think to opposite of the last poster. I have had trouble with epoxy that is out of date. It just won't go off like it should.

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http://goatrockukulele.com

Pacer Technologies maker of Z-Poxy has a data sheet available for download in which they claim a shelf life of 1 year.

I looked on the box that I have of Z-Poxy and there is no indication of a date code but the individual bottles inside the box have a coded sticker on the bottoms... Of course a buyer of Z-Poxy can't be expected to open up the box in the store and check out the bottom of the bottle and besides I see no legend online or in the box as to what the coded stickers mean... So no sign at least on my box of how to tell how old this stuff is.

I do know that I have used at least 2 year old Z-Poxy with no issues, I know it to be at least 2 years because I had it that long. Am I recommending using older than 1 year Z-Poxy? Not unless you try it on scrap and it works fine and you are comfortable with using a product that the manufacturer's own literature lists as being only good for one year.

I have some Bob Smith epoxy here that is 5 years old and even though one part has darkened a lot it still works fine. I went through this with System III and at least several years ago when I visited their web site they only claimed a shelf life of one year as well.

Like Hesh I've used zpoxy that was a least two years or more old. Think the best by dates are a little CYA type of thing but certainly would not recommend anyone using past the date unless they at least test and to be sure they should use fresh product.
Tom

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A person who has never made a mistake has never made anything!!!

I just cracked some open that I bought in 07, and it works fine. Hardens nicely, fills pores, sands easily. Can't ask for more than that!

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Waddy

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Sound Clips of most of my guitars

With epoxies, the published shelf life is a way for a corporation to cover itself legally...but if it's stored in an airtight container at room temperature there's really nothing chemically to go wrong it over any reasonable amount of time.

Test really old stuff by mixing up 10 grams in a small cup. If it cures to a state where it's completely solid there should be no reason to worry about its published mechanical properties. If ancient epoxy somehow becomes compromised, the first clue is going to be an apparent impartial cure rather a full cure with dubious mechanical properties. A full cure can look different with some epoxies due to the designed purpose of the epoxy...but the vast majority of epoxies discussed on this board will cure with a hard, clean, glossy surface. Sometimes water or other chemicals that didn't cross-link will migrate out during the cure and settle on the surface. Wiping this off with acetone or mek, one should see a hard, glossy surface beneath. If, after wiping, and after all solvents have flashed off, the surface is still appears tacky....you are looking at partially cured epoxy.

Fully cured epoxy is inert and will not be affected by common solvents.

Part A can crystallize if it's stored below room temperature. These will look like a white fog or lump in a clear bottle. If this happens then heating it for a while at 100F or so will usually bring it back to a non-crystalline state with no deterioration.

If Part B is liquid looking, and not lumpy, it's good to go.

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I read Emerson on the can. A foolish consistency is the hobgoblin of little minds...true...but a consistent reading of Emerson has its uses nevertheless.

StuMusic

Thanks for the info everyone! I will buy the zpoxy at the local hobby shop. I am testing the finish process on a 2x2 sheet of Luan plywood (someone posted that Luan is a type of mahogany) so the zpoxy will get tested before using it on my guitar.

Thanks again.

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Formerly known as Adaboy.......