How to clean a spray gun

Issue 287 June 15, 2017

Unclogging a spray gun and keeping it clean: these are the tips Dan Erlewine teaches to the young luthiers who work in his guitar repair shop.

Video Transcription

Dan Erlewine: Today, I want to show you how to clean a spray gun. The reason is because one of the guys, and it might have been me, used this with lacquer in it but didn't clean it when they were done. Now, it barely sprays. It should have a nice wide fan. I'm going to clean it and show you how I do it. If you do this every time, you won't get a clogged-up gun.

The no-drip way to pour lacquer

I can feel some built-up lacquer on the threads of this cup. I'm going to pour this back into the jar. I like to flip it over like this. Let it drip and flip. I don't get so much lacquer in the threads that way. It keeps it clean. Little thinner in there might do the trick all by itself, but I'm not going to bet on it.

Paper towel trick for cleaning threads on the finish cup

One thing I like to do at this point is I like to clean out the threads of the cap and the cap itself when I'm done by putting a little paper towel on it and just shaking it. See how that's soaking in there. Then, half screw those threads on like this and clean the threads. Leave it clean for the next man or woman.
I'm going to go turn on the fan.

Spraying thinner through the gun and cleaning the air cap

When I'm spraying thinner through the gun, to final clean it I adjust the fluid flow and the airflow bit to make sure I'm getting into all the little corners. Just sprayed a little thinner through that and adjusted the valves. But I'm going to go a little further and put the nozzle back in here with some thinner and use the brush to clean off the front of the nozzle here.

Lacquer builds up on the threads. It builds up on the air cap, and it builds up on the tip. A lot of times, you'll get lacquer that'll dry on the face here between that air hole and this air hole. It just stops the cross air from shooting. You want to take your cleaning tool and make sure the holes on each side of the air cap are clean. The fluid comes out that hole. The air comes out both sides and atomizes the fluid.

Cleaning the finish cup lid

Nine times out of 10, this will make it work great. I want to get the lid clean too. If you leave lacquer on it, it just keeps building up and building up. There's some stubborn buildup right here. If you don't get that off, then other lacquer will latch to it, and you'll find yourself trying to spray, and the hole's completely plugged. That's no good.

In the spray gun cleaning kit that we sell... It has these little tip cleaners, and the largest one is perfect for this jar. If you could see it closely, it has teeth almost like a file. These are not threads. They're ridges like a ring shank nail that clean out any dried lacquer in there. I push it from the bottom out and then clean it off because you don't want that dried lacquer falling down in.

Now, I'm going to put some of the thin-out lacquer back in it as a test and see how it sprays. Of course, then I'll have to clean the gun again. But that's all right. Yeah. Now we're talking. That's what I want.

Back in Michigan, the guy that taught me a lot about spraying, an older man than I... He's passed away. Joe Badowski taught auto body shop, and he also worked on guitars. His students had to clean their guns well enough that they could drink out of them. That's what he always said. I never did. But he swears it. Nice and clean. It'll be ready to go the next time.

Dan Erlewine

Guitar Repairman and Builder