I have some very tight spots on the sedan/delivery project where I need to shoot nearly upside down. In addition I need to shoot the belly of the car, again upside down. My HVLP guns won't do the trick.
Using some of the comments and suggestions in this thread
and a PM from Mikey poking me in the ribs to join his "Dare to be Deviant" brigade, I decided that instead of running out and buying a new pressure pot gun, I'd just try to convert one of my old siphon guns which I don't use any more.
Here is the result. This was originally a siphon type detail gun with a paddle trigger (it's so old I don't know the make or the nozzle size). Arrow "A" shows where the cup used to attach to the gun at Arrow "B". The hose is approximately 5' long and came from an old portable air pump which was deep sixed some years ago. But I KNEW this hose, which had threaded fittings on each end, would come in handy one day.
The second picture shows the changes made on the gun. I used a 1" long threaded black pipe fitting ("A") to attach the hose to the gun. The fitting on the gun had limited threads and a somewhat specialized end, so I inserted an O-ring to insure a tight fit where the black pipe fitting meets the gun. To conserve space and cut down the length of the gun, I used a street elbow ("B") for attaching the air hose.
No changes at all were needed on the cup end. The threaded fitting on the hose can be attached directly to the cup.
I immediately discovered that such a small pot, with very little weight, didn't want to stand up or stay in one place for very long. Any movement of the gun and hose would cause it to tip over. So I made this very high tech "Polyethylene Paint Cup Stabilizer"...otherwise known as a plastic coffee can filled with sand with a peanut butter jar stuffed into the center.
Just cut a hole in the lid, snap it back on the coffee can, and drop in the cup. Seems to work just fine.
I haven't shot paint with the unit yet but I did test it out with lacquer thinner and the gun seems to pull just fine. I set the cup on the floor and raised the gun a couple feet above it and the siphon had no trouble pulling the thinner. It might be a bit more difficult with actual paint, but worse case I just have to place the cup at the height I am working or perhaps a bit higher. Here's a shot showing the tight spot I was having difficulty shooting with my HVLP. The remote pot unit looks like it will fit in the space quite nicely. It will also be perfect for shooting the bottom of floor pan in the body. (Note: no small children or animals were harmed during the filming of this paint gun conversion.)