3M PPS is a game changer

[jteneyck]

Was asking you, or whoever.  Looked up 3M PPS and found a bunch of links to the cups.

A little more digging found the tips.

If I were to clean the cups, how is that any quicker than cleaning the cup I already have?

I'm a very inexperienced air painter...so I'm trying to learn here.  One reason I haven't sprayed more is because of the cleanup time vs time races by spraying.  If cleanup is that much easier, it's very attractive.  Just trying to figure out what "it" is.

Thanks!

I have an HVLP conversion gun, not a 3M gun.  It has its own needles/nozzles; nothing to replace.  I bought the gun with the 3M PPS H/O cup instead of a conventional cup.  It's clear, which is a big advantage to me.  You can spray at any angle, including upside down, another huge advantage.  

If you tried the PPS system, you would see how much faster it is to clean up than an integrated cup.  When you are done spraying, tip the gun upside down and pull the trigger to let almost all the finish in the gun drain back into the cup, leaving only a tiny amount in the gun.  You can pour the finish out of the flexible liner, OR you can put a plug in the top of the lid and put the liner/lid on the shelf to use at a later time.  I set them in a yogurt container so they don't tip over.  There's zero cleanup if you do that.  If you pour the finish out of the liner, it cleans up in less than a minute, same for the filter lid.  I'm speaking about WB finishes.  With shellac it takes a little longer but not much.  A shot of ammonia in warm water kills the shellac, or use a little DNA if you'd rather.  The liner wipes out clean.  Put the lid in a yogurt container and swish it around for a minute or two.  Pour a little more fresh ammonia/water or DNA through it and it's done.  With BIN pigmented shellac based primer, it's a toss up whether to clean the lids or throw them out.  I clean them until they start to get ratty, then toss them.  I don't use solvent based products, so I can't offer any comments about cleanup with them. 

The PPS system uses a lid on the top of the liner that has an integrated filter, so there's no need to prefilter the finish, saving time and cleanup or the expense of disposable filters.  

No lie, cleanup is about 5 minutes with WB finishes, including my gun.  If I'm spraying a project that takes more than a day, I disconnect the gun from the cup and put a plug in it at the end of the day, and then clean the gun.  Takes less than 5 minutes and I have a clean gun the next day.  Put the cup back on the gun the next day, and you're ready to spray.  

I bought 25 liners/lids around 5 years ago for about $75.  I've sprayed at least a dozen gallons of stuff since then, and still have around 20 of them left.  

Easy to use, fast to clean up, very economical; what's not to like?  

John

[fredhargis]

My first use of the system was last week. First I sprayed shellac, and then cleaned the gun with ammonia. Next I sprayed some oil based varnish something I seldom do. Then cleaned the gun with paint thinner. In both cases the clean was as simple as remove the finish cup, put on a cup with the cleaner needed and spray some through the gun. I then pulled the needle/nozzle/air cap and cleaned them separately in a container of the cleaner. Done.

[alexh1]

I bought the 3M gun with pressurized cup that uses the plastic tips. The only limit I have found on the plastic tips is that the tip retention clips start to wear and thus tip may come loose while spraying which is a do over. But I can usually use them 5 times or so. I only bought the 3M gun because I needed a second gun with pressurized cup for conversion varnish. Could not get that out of a gravity gun fast enough even at 30 secs viscosity on Ford cup. I only shoot solvent based finishes and the tip can be cleaned with a couple squirts from a can of brake cleaner. Even with a gravity gun + PPS, its still a bit of a chore to clean the passages in the gun.


Solvents are now $25/gal and it takes quite a bit to clean a gravity cup gun so the PPS liners and top are probably about the same cost as a solvent cleanup and avoids skin contact with solvents. I also had issues with lacquer based solvent finishes degrading the gravity cup lid gasket after just 2 uses or so and then it leaks if you tip the gun - a holy mess that no longer occurs with PPS. I suppose thats why you used to see the automotive guys with blue tape wrapped around the lid.



The PPS is a no brainer with solvent based finishes, not sure what advantage it is with WB except that can spray at all angles. I suppose if you can easily clean the liner and filter for reuse then it makes sense.