Quote:
Originally Posted by mark poulson
Downriver,
Why does D2T stay tacky if you mix in a thinner before the two part mix is thoroughly mixed?
I'm guessing the thinner bonds to one part better than the other, and screws up the mix if they're not already mixed before it's added.
But I'm certainly no chemist, or epoxy solvent expert, although I have tested my share of alcohol "solvents".
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Some epoxies react with hydrogen and/or oxygen as part of their curing process. Alcohol contains hydrogen and oxygen molecules that will react with the epoxy before it can react with the hardener. Alcohol is low viscosity, so those molecules are flowing around linking with the resin faster than the hardener can. I'm about positive that even if you used it after the mix, you're still not getting a full cure. If you thin it with DNA, I'd bump the hardener up 10% or so and see what happens. Should get a much better cure and ALOT less yellowing. Remember that an improperly cured film will yellow very fast, no matter what quality epoxy you use.
