3M PPS Question

[Ken Casser]

I've been using the PPS for several years with great success. I'm wondering if anyone regularly saves finish in the cup with a plug inserted to reuse at a later date? Doesn't the finish congeal in the lid screen? How do you mix it up before spraying? I spray nitrocellulose lacquer, shellac and polyurethane, and lately I've been doing touch-ups and smaller jobs, and I use a fresh cup and lid every time because I can't risk spraying bad finish. But the cost is adding up. Any suggestions?

Thank you!

Ken

[Mark Kornell]

I use PPS, too. I clean and reuse my cups and lids. They seem to last for a long time. I keep a set each for WB finishes, shellac and nitro, get at least 20 uses from a set before needing replacement.

I tear the screen out of the lid after first use. Use cone filters when filling the cup.

And because the finish in the cup is not exposed to air, I almost always pour any excess back into the can rather than trying to plug the cup. But, I've seen auto body guys simply squeeze the excess air out of a cup and then plug it. Seems to keep for weeks.

Obviously, I don't pour back for catalyzed finishes. Even so, the cups and lids can be cleaned and reused. The lids I clean when I clean the gun. For the cups, I pour off the excess into a waste can and then let the remainder cure in the cup. The cured bit pops out or flakes off quite readily by the next day.

[Ken Casser]

Perfect!!! Thank you for all those ideas. You've saved me a bundle. Now the only problem I have is my large cups seem to stick inside the pot so I end up ruining them trying to pry them out. I've tried cleaning the pot with lacquer thinner, I tried dusting baby powder in there but they always stick. Have you had that problem?

[Mark Kornell]

Ken,

I've never had that problem. Makes me think you're getting finish in between the liner and the cup somehow.

[Matt Meiser]

I used to. I'd squeeze the bottle down until a small bit of finish came out--no big deal if using waterborne finishes since it rinses right off. I kept a few Target and General Finishes products that way for a few months with success. I did find they liked to tip over but saved sour cream or cottage cheese containers from the kitchen held them nicely.