[techron]

hi guys, i have a couple of pints of unopened urethane hardener that are 2, 3 years old. does this stuff have a shelf life or is it OK to use? does hardener go bad? thanks.

[302 Z28]

Depends on where it has been stored and for how long. In a garage where the temp can reach 100+ it will heat harden in a very short time. If it is not discolored or cloudy it's probably OK to use, but I would test it on a small batch first.

Vince

[Rag top bird]

I agree with 302 but if it where me I wouldn't take a chance with the cost of paint and clear today

[deadbodyman]

It should still be good just shake it ,if it still sloshes around like water its ok if it's slow like syrup its not (well not really,you can still use it for jambs it'll dry real fast)..once you open it,it wont last long though ..I've had hardner go bad in a week when its hot and humid....you can use your mig gas to replace the air in the opened can and it'll last a lot longer...Barry K taught me that one...I always shake up my hardner before using it ...

[001mustang]

I had some old bondo that never kicked 100%. Gummed up paper. Had to remove. Wasn't that big a deal.

[techron]

thanks for the posts everyone. 302, i know you know your stuff.
ragtop, as soon as you posted yesterday i knew the answer, it is a no brainer, buy new, why even take a chance. hardener is cheap. i have 1000s of hours into the early corvette restomod i am building. 100s in bodywork and panel replacement on the coupe. after all that i have blocked it to death after spraying hi build primer surfacer to insure it is perfectly flat. i would be an idiot to risk all that on old hardener!!! NEW hardener it is.

deadbodyman--> i have read your posts since you joined and always enjoyed them. you know your stuff. i went out and checked my paint stash right after the origonal post. i bought a bunch of stuff, extra stuff when i did the restore and painted my pantera 2/3 years ago so i would not run short of materials in the middle. you are right on, i had one open pint and one unopened pint of hardener, i shook them yesterday, as you said, the unopened pint shakes like water. the opened pint shakes more like very light/penetrating oil. although i am cheap, new hardener is not the place to cheap out-->new hardener is ordered.

as for your avatar, i would love to shoot with you sometime. i reload my own rounds, i enjoy shooting 44 mags at 100yds (S&W revolver 8 3/8 BBL and ruger 7 1/2BBL SBH single action) on silouet targets my groups are much tighter than yours...

[deadbodyman]

OMG ,I didnt know the whole story,
in a case like that of coarse you would buy new ,save that old stuff for your wifes car (if she drives like mine it never gets old in the first place) I wouldn't even use old stuff on the jambs of a project car...

[ogre]

buy new stuff, that said...

i had left over keystone epoxy primer/hardener from painting my son's elco 8 yrs ago
we must have used 4 oz of primer (out of a gal) & a splash of hardener
stored in the barn in michigan; 99 degree summer and 0 degree winters
and since i was going to sand most of it off, i used it
worked fine.
i tossed the left overs so i wouldn't be tempted again in 8 yrs

[65ELCMO]

after age 60......Yes

[deadbodyman]

Oh,you are a fresh one. I found some thats guaranteed to get hard.....even under water.