Using old epoxy activator. Why not?

TerryAT

New Member
New to the forums, but been following , on and off for some time. Anyways, I have some, way over the "opened" shelf life, epoxy activator left. I also have some gray primer, old as well, thats been stored in my basement cabinet. So the other day I pulled them out and stirred the primer, and mixed with the "aged" activator, ( just about 6 oz total) ,and using a foam brush, spread some over a inner part of a 67 Chevelle fender, and a steel 1" plate.. as a test. They are both totally dry, and appear like a day old primer! . SO , why not use the stuff?? I am thinking on using it on, non painted surfaces of my Chevelle (floorboards, inside trunk areas, etc). If its hardened, whats to worry about? Im totally stunned that it dried, to be honest.
I airbrushed some bike parts in the past, and found out the hard way about the life of "opened hardeners" in my clear. The clear on that tank felt rubbery, and left fingernail imprints in it. And so I had to strip it all off, artwork included. I expected the same to happen here, with the epoxy. and am surprised that maybe I can still use whats left. As you know, nothings cheap these days.

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i have never had an issue with old epoxy activator. epoxy is a totally different ball game and chemistry than urethane activators though. old clear and primer activator can become weak. only thing i can see with epoxy is the activator gets a super deep amber/red color so will make your white epoxy look a bit yellow. never had it not kick off the primer though.
 
i have never had an issue with old epoxy activator. epoxy is a totally different ball game and chemistry than urethane activators though. old clear and primer activator can become weak. only thing i can see with epoxy is the activator gets a super deep amber/red color so will make your white epoxy look a bit yellow. never had it not kick off the primer though.
Thats why I had to ask. Reading tech sheets and people even saying that theres an "open shelf life", as if compared to a date on a gallon of milk! No good afterwards. An expiration date, if you will.
After I had the clearcoat issue in the past, HOK, I now always write the date on the product when opened.. The epoxy I used here is from 2010, the activator , 2014! 9 yrs after , the way I took it, as expired, dont use. But apparently its still "kick'in.
 
It's funny you posted this today because just last night I was pondering the same question! I'm going to have to order another gallon of epoxy to finish my current project I have another project coming up very shortly afterwards (a 1974 challenger) I noticed the price of epoxy per gallon ( 2 gallons after mixing ) is alot cheaper than buying a 4 quarts or in my case I was going to buy 2 quarts (one gallon after mixing) but it's only like 70 dollars more to get the whole extra gallon its a 146 dollar saving when buying 2 gallons. But I was worried about it "expiring" before I started my next project. I'm not sure how the 1 gallon activator is shipped? Is it 4 individually quarts or a one gallon can? Once it's opened the whole gallon is opened? I'd hate to waste it! My shop is not exactly temperature controlled. I have heat and air but it only runs when I'm in there. The epoxy I'm using now is 4 years old but it was unopened. I bought 2 quarts I used one when I bought it and just opened the 2nd one the other day. But I can already tell I'm gonna need more.
 
That's a reply my father would say. No way can that reply be disputed.

Outstanding art work, TerryAT. You've been blessed with a wonderful talent.
Thanks , I never intended to include the art. I just threw the primer pieces on the table to take a picture.
My mother was good at art , so I got the talent from her! My 6 brothers and sisters, somehow didnt? From there I was self taught, played around eventually with an airbrush, and made some money painting Harley and Corvette items to sell on E-Bay which helped pay for me to redo a 66 Nova I had . It was the first and only car I ever painted. Stripped it all down and repainted the same original color. Should have kept if, but I wanted a Chevelle. And it sits now, 1/2 done in the garage. Been on hold for a few years, but now Im getting interested again. Heres the finished '66 Nova.....and '67 Chevelle when I got it.
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It's funny you posted this today because just last night I was pondering the same question! I'm going to have to order another gallon of epoxy to finish my current project I have another project coming up very shortly afterwards (a 1974 challenger) I noticed the price of epoxy per gallon ( 2 gallons after mixing ) is alot cheaper than buying a 4 quarts or in my case I was going to buy 2 quarts (one gallon after mixing) but it's only like 70 dollars more to get the whole extra gallon its a 146 dollar saving when buying 2 gallons. But I was worried about it "expiring" before I started my next project. I'm not sure how the 1 gallon activator is shipped? Is it 4 individually quarts or a one gallon can? Once it's opened the whole gallon is opened? I'd hate to waste it! My shop is not exactly temperature controlled. I have heat and air but it only runs when I'm in there. The epoxy I'm using now is 4 years old but it was unopened. I bought 2 quarts I used one when I bought it and just opened the 2nd one the other day. But I can already tell I'm gonna need more.
Mine is a 1 gallon can.
 
I usually pour new into older cans and keep the newest sealed until I use up what I've poured into the other cans. I use a lot of epoxy so it really doesn't have time to get too old lol.
 
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