One for the painters

[moparspares]

Does Clear Coat Go Off

Today I mixed some clear coat up to do some repairs. I have had it sitting on the shelf a while and when I sprayed it it came out of the gun like string. Dumped that and mixed up some more from a newer can I had and it sprayed beautiful and smooth.

Does it go bad if sitting a while.

 

[B-onefan]

Yes it does. Well, not the clear itself, but the hardener goes bad. Once the seal is broken, and air with moisture is allowed to enter the can, it is usually only good for a few days to a few weeks, depending on humidity.

 

[cudavert]

Probably got thickened up. My first paint job on my motorcycle, I did the same thing but it was due to me mixing the clear wrong. It came outta the gun like Silly String.

 

[Swinger340Canuc]

Yes, like B-onefan says its in the air, to be specific the hardener is has Isocyanates in it and that chemical is highly attracted to water or water vapour so it will spoil if exposed to too much air.

 

[moparspares]

Dont think it was the hardner as I used the same in both batches I mixed. The difference was the actual clear itself.

 

[RedFish]

Just for the sake of saying... now that you know you can mix 2K clear wrong and get a texture from it... Feck around with volume and pressure until it sputters, recreate the grain on surfaces like dash cap repairs. I've been there done that. Use the cheapest little gun you can find though and work quick. Get the texture you want on a test surface and geter done. If that stuff sets up in the gun, its trashed.

 

[B-onefan]

Then I would say the clear had lost some of the solvent and was too thick. The cap may not have been closed all the way allowing it to evaporate. Lacquer Clear would do the same thing it was not thinned properly.

 

[B-onefan]

Yes, like B-onefan says its in the air, to be specific the hardener is has Isocyanates in it and that chemical is highly attracted to water or water vapour so it will spoil if exposed to too much air.

I used to teach students the importance of closing everything good and marking an open date on hardener, by mixing a small amount of clear and hardener and also pouring the some hardener only in a cup and adding 2 drops of water and letting them sit till the next day. Both would be hard as a rock! I also would pour a small cup of lacquer clear and let it sit the same amount of time. About a month later, we would add solvent back to all three and see which one would re-dissolve. I had a great time teaching young high school men how to repair and paint cars until some shortsighted new administrator decided all kids are going to college and we should no longer be teaching students how to work on cars.

 

[evil 340]

I have ppg clear that is over eight years old from when I painted my demon. I used it last year on my buddies mustang rims with new hardener and it was fine.