Technical Paint age

I have some Summit Single Stage Polyurethane paint that is 10 years old. The can has been opened way back, it appears ok.
How do I tell if the paint is ok?
Can I use it ?
I also have some Summit 2K high build primer 10 years old in an un opened can.
Same questions.
I would buy new activators and reducers.
If I can use this stuff it would save me a couple hundred bucks, not a huge amount of $s but… Also not worth problems.
Thanks in advance.
Dan

 

Test panel!
@anothercarguy showed what happens even with fresh stuff and following instructions.

 

I have used paint that is older than that with good results. I would at least mix some up and try it on an old fender or whatever you have laying around.

 

In my experience it’s the catalyst that goes bad not the paint. May take a while to mix though.

 

I have used single stage polyurethane that old many times. It could be a ****shoot (intentional pun) . New activator and reducer is a wise move. I usually only use paint that old for wheels, underbodies, door jambs, etc. but not a finish top coat. As RodStRace stated, a test panel will make your mind up whether it is usable for your internded purpose. The same will apply to the 2K primer as well. It has to be able to bond to the prepped surface as well as to subsequent coats. Yeah, I hate to waste paint supplies and always try to use it up somewhere if I can. I have run out of room in my flameable resistant cabinets. Last year I made a bunch of trellises for my wifes rose bushes. Yep, leftover car paint coated.

 

I wouldn't use it for anything that is going to **** if it fails down the road. Unfortuantley test panels don't let you know how it will hold up. Absolutely need new hardeners and reducers they degrade much faster than the paint.

 

I have done that before with normal results. I used some from 2007 last summer and it was no different than when I 1st used it. However, if I would have opened the can and everything was separated or strange colored, I don't think I would have used it. I usually wrap tape around the top of the can to try and make it as airtight as I can.

 

Test panel is the only way to tell, spray the primer and let it cure sand it then spray the paint. Then you know.

 

Just because something sprays ok, and dries. Doesn't mean it has actually crosslinked. Or even bonded correctly, to a substrate. You need to test for that also. Especially if you want to use it in a highly cosmetic capacity.

 

I’ve got **** at school that’s 20 years old.
Shoot it all the time
Shot some red base last week that we had to punch a hole in it to get to the liquid part.
If it will squirt out the gun, we’ll spray it.
Hardeners will go bad but I havent had issues with old paint.
but I’m spraying junk or teaching with it.

The blue was mixed a couple weeks ago. The white was mixed in 2017. The clear is ancient.

 

The paint on the 38 in the avatar was shot before 1985, I used some that was left over of it four? years ago on the interior trim of the Studebaker, it looked good when I sold it a couple of years ago. It must still be good since the guy that owns the Stude told me a couple of days ago that the only thing wrong with the car is the rear transmission seal. If I remember correctly (without venturing to the shop to check) it was R-M paint??

 

I can attest to that!!

Photo from my build thread...hate learning the hard way...but those lessons stick (even if the paint doesn't ).

 

How do you test the bond?
Dan

 

I think it’s worth a shot, I agree with other suggestions, new catalyst for sure. I’d do a test panel on a painted panel maybe a fender a body shop has put in the s**** pile. Old paint can be thick, if it seems to be then put a little reducer in it before mixing being careful to over reduce. Stir the paint a lot and strain it before mixing.

 

Single-stage polyurethane (2K) paint generally has a shelf life of 1 to 3 years for unopened paint, while activators/hardeners, which are sensitive to moisture, often expire within 6 months to 1 year. Proper storage (room temperature, sealed tightly) can extend this, but activated material only lasts for a few hours. Google info.

• Best Overall Value: PPG Shopline or Omni are frequently praised for providing professional-grade, durable urethane finishes at a reasonable price point. Google info

My advice, worth the price you paid. I used Omni a few years back to repaint road rash damage, entire front of my black 51 Merc. Turned out great. Like all paint Follow the directions to the letter. matching , primer, clear, reducers, temp, humidity, air pressure, water filters for your compressor And buy a good respirator with the best filters, I used Hepa level as I'm told the new paint can/will kill you. I'm not a pro painter, just a hobby guy, painted a lot of stuff in the driveway years ago, running the gun is the easy part, it's the prep part that shows. Note ! A few bugs, a sag/run some over spray with a few fish eyes nobody will notice but you. I've dealt with pro painters through the years, disappointed the majority of the time. IMO the paint fumes must get to them. You can do this, Making a plastic spray booth helps and you built the car, you might as well paint it, it's a driver. Drive it, Enjoy it, repeat as needed. Another tip, white forgives, black does not.

 

There are industry test methods that can be used to test the bond. Or you could devise a rudimentary test to try at home. Honestly, if you're wanting to go to that length, just buy new paint. The price per gallon of Summit single stage paint isn't worth messing around.

 

This is for the Dirt Cheap Dart after all !
My wife says I’m a tight ***, I can rub two nickels together and get 11 cents well maybe 9 cents.
Dan

 

I’ll try that on a test panel. I have some Zip tape that has a very strong bond.
Thanks
Dan

 

Google info is lying to you. : )

 

I've only ever had paint come off because the underlying surface either wasn't prepped properly, or it was overly wetsanded smooth (not enough for the paint to grip to).

The last paint I sprayed was mixed with random brands of body shop leftovers of all ages in a washed-out Taco Bell cup until I had a color that matched good enough and I sprayed it. Granted, that was basecoat, but it's holding up just fine. Strainers are your friend with old paint.

I have to admit, I have zero experience with single stage polyurethane, so maybe the rules are different for that stuff. But I've used enamel, lacquer and basecoat that were all decades old and I never had an issue.

 

Lacquer and base coats, have a significantly longer usable self life. ( probably almost indefinitely, if not abused in storage ) Than catalyzed resin systems. Where atmospheric oxygen and moisture intrusion. Can degrade both the resin and catalyst. Usually the catalyst is much more sensitive to this. Especially if it has been opened before. And, not factory sealed still. Most manufacturers will have a specified self life.

I've shot some older 2K materials before, and just sitting there, they looked fine. But, if you had to get into them. You could tell they were not.

 

How small should the squares be? 1/4" X 1/4"? or smaller?

 

The paint adhesion test at the dealer was tape pressed securely on the paint, then rip it off quickly.
If the paint came off, you were eligible for a warranty re-spray.

 

Good info guys
Thank you
I plan on testing if ok I’ll use if not I’ll buy new.
I don’t want paint coming off in sheets
Dan And if the pros have problems I’m screwed.
Dan

 

Stir it a long time, strain it, mix a small amount and spray it on something see how it looks after it sets up and drys if it looks ok use it. Adhesion testing the paint with tape before it’s cured will pull paint off, there’s a lot of variables that go into curing time. In my opinion adhesion isn’t the question it’s more the condition of the paint with fresh catalyst, how it sprays and if it sets up and drys properly.

 

If it's liquid, spray it. If it's solid, toss it.

 

It’s always cheaper to use old ****py paint materials that may or may not work/last. Then you can do it all over again when things don’t work out, and that’s always the most efficient way to paint a vehicle.

Personally I would look into using industrial urethane, usually it comes mixed three quarts in a gallon can and you mix it four to one with the hardener. It’s always solid colors so no metallics but if you want to get creative you can use Pearl topcoats, then clear urethane. Most jobbers have factory truck colors like red, white mix formula, I use Diamond Vogel paints and they had mixed formula for new Kabota orange when I bought paint for my Mopar engines. The thing I like about using industrial paints is there’s all types of products for them, I sprayed parts for a skid steer that I needed to lay on the side I just sprayed to paint the other side so I used the fastest activator and I was able to lay the over in fifteen minutes with no marks in the fresh paint.
A spray able gallon is a fraction of what automotive paint is plus it buffs nice and it can be clear coated..