Novice sprayer needs advice..

[Clisby Clark]

So far, I've only sprayed water based acrylics and clear coats with my Fuji unit. When cleaning up, I'm sure I've probably overcleaned the system spraying a full cup of water through the gun after washing out the cup with water and soaking the aircap unit. This uses a lot of water but that's ok because water is practically free. Now I want to spray some shellac and understand I must clean using alcohol which is not nearly so cheap. My question is what process do you use to clean your guns when spraying with non water-solvent products? Is it possible to spray solvents into a container and reuse them for later cleanings? Thanks for all input!

[Scott Holmes]

Yes you can srpray into a container and reues the solvent DNA for shellac.

However, WATER IS NOT the solvent for waterborne finishes it is only a thinner (hence the more correct term water-borne or dispersed). To me "water based" means it's made from water (e.g. beer is made from water) acrylic finishes are not. You should clean your equipment with somthing stronger than water. Say soapy water or even better lacquer thinner. Only rinsing your equipment with water is going to lead to problems down the road unless you completely take it completely apart and clean and dry every piece.

Check with the directions on your gun; but I suspect that cleaning with water then putting it away is a bad idea. Most need to be oiled or at least have mineral spirts run through them.

[Larry Fox]

I have a PP-based system so I run a bunch of water (like a gallon) through to clear out most of the finish and then blow it dry for a few minutes and then I run about a quart of DNA through it. I also tear the gun down every few jobs. Might be overkill but spray guns cost a lot more than DNA.

[Frederick Rowe]

You should be able to clean up WB finishes with soap and water if the finish has not dried. Disassemble the gun, use a stiff bristle toothbrush, and scrub with a hot soap/water solution then rinse in hot water. Wipe down all parts with a cloth and let air dry before re-assembly. Shake out the gun to ensure no water sitting in a cavity within the gun remains. Run the soap/water through the pressure tube and check valve, then rinse. Blow through it to clear out water. Remove any gaskets in the cup and scrub with other parts in case some finish has wicked beneath them.

To clean dried WB finish, try acetone. Soak the nozzle, cap needle in a sealed glass jar overnight, then scrub with cleaning brush. The acetone will flash off quickly, then lube and reassemble.

Closely inspect the air cap and the small air holes. They can easily be clogged by dried finish. Run a thin strand of music wire through the holes to check for obstructions.

You should have no problems moving from WB finish to shellac. As long as the cleaning agent - be it solvent or water - has evaporated before you change materials. I would recommend always disassembling and cleaning your gun after the end of the day - then let it air dry overnight.

Be careful choosing a gun lube. It should not contain either silicone or petroleum distillates which would contaminate your finish. Use only a little on the needle as it passes through the packing nut.

[Jamie Schmitz]

Ammonia also cleans up shellac but it does not do that great of a job, and I would not use it if you plan on reusing the alcohol. Maybe for a first rinse on the cup.Shellac is useful but very messy/sticky.