Here's a questions I should have asked first...

JRSutton

Well-known Member
How would one clean epoxy primer out of a spray gun???

I did get a spec sheet with the primer, and the answer's probably in there, but I can't find it.

Thankfully it was a cheap touch up gun.
 
I use lacquer thinner. I use to clean the spray gun after disassembling it and let all the parts soak in it until I was ready to use it again. Buy yourself some small brushes so you can clean the pickup tube of any any paint. I hooked a wire to the parts so they don't come loose and you don't have to fish the bucket of lacquer thinner trying to find them. When I'm ready to paint again I shoot some of that lacquer thinner through the gun before trying to paint. Hal
 
You should always disassemble your gun and clean all parts in a solvent [b:654c4848f0][i:654c4848f0]after each use[/i:654c4848f0][/b:654c4848f0]. That is especially important when using two-part paint products (like epoxy) as those types of products have a definite pot life, sometimes a very short one, where the product will gell inside the gun passages and be difficult to remove if left there. I use a dedicated gun cleaner for normal cleaning. You can also buy a special gun cleaner that is basically a paint remover for trying to restore a gun that has not been cleaned properly. I've never tried that so don"t know how it works.
 
Don't throw the gun away. Take it apart and put it in a can with paint and varnish remover for a couple of hours then rinse it off. Then finish washing it with lacquer thinner. Works for me. I have a habit of leaving paint in a gun for six months at a time.
 
Rod is correct. First I wash the cup out with PPG MS251, then backflush the gun by loosening the cap and using about 10 psi air. This forces the paint back into the cup, any more psi forces the fluid to splash out. I do that a few times until the fluid is clean. Then I tighten the cap and spray fresh fluid out. Then I take the cap and needle off and soak or rinse them and reassemble. I very seldom have to clean any dried crud out because I never leave paint in the gun, not even for a few minutes.
 
Thanks- that's a good idea.

It was a cheap $35 touch up gun and I was considering it dead, but - 35 bucks is 35 bucks.

I'll soak it in some paint stripper - got nothing to lose by trying.
 
I do normally clean the whole thing completely as you suggest.

But this is the first time I used an epoxy primer.

By the time I was done, I went to clean it out and I couldn't get much of the primer out.

All I had was mineral spirits and naptha. They were about as useful as water.

Perhaps it wasn't so much what I was using to clean it, but instead maybe I waited too long and it began to cure in the gun?

Either way, I'll use lacquer thinner next time.

Thank you everybody for your advice.
 
Great idea wiring the parts. I had considered just letting the parts soak while I'm not using the gun, I like the idea of wiring so you don't have to go fishing for them.

Thanks
 
I did not know of the backflushing trick.

When you say you loosen the cap - does that mean the front "nozzle" of the gun?
 
Yes, you loosen it until it almost falls off. Keep the pressure low and keep your eyes out of the way, or wear goggles, I wear my glasses. It does work.
 
MS 251 or a similar product is better than lacquer thinner, you can also use your reducer, but it costs 3x as much as 251. I do not consider lacquer thinner a good product for urethane or epoxy.
 
Well I finally found a local source for pro paint products.

so I will check out the ms251 stuff.

Thanks again
 
Follow up: paint stripper cleaned the gun out nicely. Good as new.

I grabbed some lacquer thinner while I was at home depot the other day - and I tried priming again yesterday. MUCH better results when it came to cleaning up.

Last time I had used mineral spirits, and that was uselss. The lacquer thinner cleaned it right up.

Thanks again to all.
 

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