Primer, how long can it last in a sealed can?

[5.7 hemi]

I used some primer my dad gave me today, what a freakin' mistake. He has had it for 2 years, never opened. Well since he has the coin to pay for his car to get done, he gave me alot of stuff to get mine done. Well I spent a half hour mixing the primer, used my cordless drill with a metal paint stirer. The directions said to use (1) 75ml tube of hardner per quart. Simple, well no, it started to gell after I got the fender and bumper coated with about 2 coats each. The outside temp hit 88 and I can not figure out what the hell happened. So I spent 2 hours cleaning the gun. Poured a 1/2 quart of primer and about 10 drops of hardner, same crap all over again. I spent more time cleaning the gun than the first time. So, I called my dad and said that I wont be using this stuff anymore, but thanks for giving it to me, and he said he would call Eastwood and find out what happened. This brand of primer is Evercoat. Anyone got any clues?

 

[morbidgoat]

possibly the wrong activator. typical primers ive used have 3 different activators to use depending on the temp slow activator equals high temp outside (takes longer for it to cure) if your using an activator that is designed for 60-70 degree temps when its almost 90 it will kick faster or if your using too much hardner. i have never seen a primer that came with tubes of hardner ive always used gallons of primer that used quarts of activator at a 4 to 1 or 4 to 1 to 1(reducer) mix rate but these are also urethane primers i use and you didnt say what type yours is

 

[challengergary]

I've never heard of primer with a tubed activator either.

 

[challengergary]

BTW -Most primer will pretty much last indefinitely in a sealed can especially if it requires and activator. It will settle and separate but will still be good as far as I know.

 

[jaak]

Its polyester primer...(probably slicksand or featherfill). What was the temp, when mixing/shooting. with poly primer, you need to activate it....shoot it quick as possible, then clean your gun, it has a very short pot life once activated. Did you add the activator...then stir for 30 minutes? if so I think thats your problem, you should stir it a long time without the activator to get all the solids (sunk down to the bottom of the can) mixed well. Then pour what your gonna use in a mixing cup, add your activator, stir it, then shoot. Another note on Polyester primer...you need a huge tip in your gun to shoot it with. I have a cheap gun with a 2.0 tip just for polyester primer, and I still have to thin it about 10% to get it to flow-out smooth. If your gun has a smaller tip than a 2.0, don't even try to shoot it.

Jason

 

[5.7 hemi]

Tip size is 1.8, added activator after stirring for 30 minutes. It is a polyester primer and it was hot outside so I think the temperture of the activator was for a lower temperture. I never had a problem with the other brand that I have been using, so it's gotta be the activator. What I mean by tubes, is it looks like a samll tube of toothpaste, clear liquid that resembles water. It's no biggie, I was just curious and will go back to the brand I normally use.

 

[Donny]

Yeah, I've used Epoxy Dupont primer that has sat for about 4-7 years, stirred it up, put it on, it was good to go. Don't recommend it, but, I did it!

 

[keeper of the plains]

The polyester primers are a heavier build(thicker) and do have a short pot life. a bigger needle/cap combo would be a easier to work with. the ratio w that primer is 1 tube-1 gallon of primer. 1 good thing about those primers are no shrinkage.one of the cons is that stuff doesnt sand as good as a urethane primer.

 

[66_B_Body4ever]

My experience has been that you're rolling the dice with material that has been sitting for more than a year. Polyester primer is basically sprayable body filler and we all know how quick it can cure on a warm day. Using fresh hardener might help but you should get the right stuff for the primer surfacer. Epoxy (as Donny mentioned) is much higher quality material and as a result can have a longer shelf life, but is not a sandable primer. Urethane based primer surfacers are not recommended to be used if they exceed a shelf life of a year...unopened. Once any material has been exposed to the atmosphere the shelf life can be shortened dramatically depending on the resin base.

High build polyester primers are ok to use for blocking but should have an application of urethane surfacer applied on top prior to final prep for paint...

 

[5.7 hemi]

So I will seal it once all primered, got it. The temperture here is only going to get hotter now that summer is closing in, usually agout 100-115, so a slow activator will be a necessity, along with a steady I.V. to keep from getting heat stroke, ha! Thanks guys for all the advice.