3M PPS spray finishing system

I spray a lot of my finishes, stains, dyes, lacquer and shellac all go through guns in my makeshift spray booth. I use an inexpensive Harbor Freight HVLP conversion gun (item # 43430) which I was happy enough with until I was introduced to a new product at a Minnesota Woodworkers Guild Meeting. The PPS system made my old cup obsolete. My gun is still good to go with the addition of an adapter(#2) provided by John Zoia, the 3M rep. I have converted over to PPS.

Gun with old cup

The parts of the PPS

The assembled gun

The assembled gun prior to purge

The assembled gun after purge. After connecting to the air line and pulling the trigger the gun has evacuated all of the air from the collapsible cup.The gun can now be held and sprayed from any angle and it does not leak.

To remove the gun disconnect the air hose and turn it upside down, pull the trigger which causes the collapsible cup to pull the finish from the gun, twist and pull and the gun comes off of the cup. Put the plug in the cup.

Squirt in a bit of the appropriate thinner, pull the trigger, and the gun is clean(airline disconnected).

Things to remember when using this system, The collapsible liners are clear, be sure there is one in there before pouring in the finish. Be sure to remove the airline then pull the trigger and let the finish be pulled out of the gun before you remove it from the cup.

I find it is much easier for me to switch from one type of finish to another. Clean up is much simpler, I actually clean the gun after every use, and I use much less thinner in the clean up. You don't clean the cups at all just throw them away. The cups have built in strainers and you can store finish in them for a short amount of time.