Cleaning Routine for an Air-Assisted Airless Pump

Finishers advise on taking care of our AAA unit, before and after use. October 25, 2006

Can anyone help me with a cleaning routine for my 10:14 / MVX? Currently I am flushing the system with lacquer thinner, then leaving it empty. Should I leave it filled with fluid? Also, someone suggested flushing it with acetone or mineral spirits after flushing with lacquer thinner. Is this okay? Lately, my tip has been getting clogged a lot (every few minutes). I assume there is buildup in the hoses. I am spraying Gemini pre-cat lacquer.

Forum Responses
(Finishing Forum)
From contributor B:
Daily flushing with a good quality lacquer thinner should be fine. I do recommend not draining the lines, as residual product could dry out and plug your gun filter and tip. A good flushing on Friday with thinner, then a blend 50/50 with butyl cellosolve to run through the lines. On Monday morning, flush with lacquer thinner, then pump product through. Do not soak the gun in thinner, though - just the tip and air cap (wetted parts). I soaked the whole gun and it began to leak air around the trigger after a short time.

From contributor D:
I would flush it with lacquer thinner and leave the thinner in the lines. Once you turn the pump off, pull the trigger to relieve pressure.

From contributor K:
Thanks for the replies. One of my concerns is that I only use the sprayer about 3 or 4 times a month. Is it still okay to leave thinner in the lines? Also, what do I do about the buildup that is already in the lines?

From contributor E:
Like you, my system sits idle for days, weeks between use. I keep thinner in the line and flush before and after use. I have two hose kits and will add more if I need to expand beyond white and clear. Acetone is fine for a cleaning flush, but I wouldn't leave it in the line for down time - only lacquer thinner.

I agree with contributor B - the gun doesn't need much attention. Perhaps a wipe around the air holes and threads if you see something or screw up and spray with a loose cap. Mostly, it can go for a long time with no attention. Mine gets overspray from use inside big cabinets.

The tips get clogged, so keep a small wash jar or bench bucket ready. I'll give the tip and cap a dip/brush and perhaps a blast of compressed air while wet (in a safe direction) and they usually work as new. It all depends on the material. The pigment in white clogs fast. With clear pre-cat, I can get past a gallon or so before I have to pause and wash the tip. It's a quick process.

Bottom line, once the line gets wet, keep it that way and don't let material (other than thinner) sit in the line for more than a few hours. The skinny fluid line is easy to clean, but it can clog if you forget to flush. My wash thinner is good for perhaps 2 rounds and I start with new. Not such a big loss. It takes so little to clean the system.

From contributor J:
We own 6 of these systems:
1. Sealer
2. Lacquer
3. Tint and stain
4. Primer
5. Paint
6. Emergency backup
All with agitator lids.

I know it's nuts - we had 4 and I just bought out a competitor. With the exception of the primer system, which we flush regularly, we leave the finish material in the systems (under pressure) for weeks between uses. (Kremlin will tell you not to.) The spray tips live in baby food jars of thinner when not in use. Before spraying, we'll agitate for a few minutes and purge the product in the hose back into the can before screwing on the tip. When we clean a system, we leave thinner in the lines, also under pressure. We remove the siphon wand quickly from the thinner can and turn it upside down and cap it.

From contributor G:
Contributor J has it down the way it should be done, keeping material in it pressurized. Remember what you're using. Oh, and another point to note - when keeping it pressurized with solvent, if going for a long time between uses, make sure piston is in "down" position. Doesn't let air into chamber and dry out product.