cleaning your gun

Can some of u paint gurus, give us a run down on a complete cleaning proses for your pain gun?
i have always used waterborne paints in my wood working shop. i just tried my hand at a 2 part urethane clear coat.i will try colors next.
i tried to clean the gun with thinners but found that it turned the urethane to goo. so then u used Acetone. it seemed to work fine. is acetone the cleaner of choice?
can u describe the process u go through from start to Finnish. is there a system i can set up and follow?
i was thinking u might have a couple of pails that u store used cleaner in, in dif stages of cleanliness?
i would run new cleaner through the gun once and put it in pail #1. then put new cleaner though and put that in pail#2, and so on until the gun was clean. then next time i clean the gun, i would start with pail #1 and reuse it, then go to pail #2, and so on.
Is this overkill?
How do u guys do it?

Also, I have seen "gun wash" products on paint supplier sites - what makes these different than using something like thinner or acetone? Are they worth purchasing or just a waste of cash?

I use MEK for all gun cleaning, and clean the gun immediately after I am finished spraying. MEK works with all solvent based paints, and is also compatible with all solvent bases. I use water with water based Acrylics, followed up by Acetone. Once paint congeals in a gun, it must almost always be disassembled for cleaning. Personally I try to avoid HVLP guns, but that is getting hard to do these days. "thinners" or "Reducers" are not compatible with all paints. They are a blend of solvents that are designed for specific paints.

When you say "use", what exactly is the process? Do you just pour some MEK into the cup and spray it out? What do you use to determine a state of clean without disassembly?

No smart ass questions....I could find next to no info on cleaning the guns when I was painting and found it very frustrating (especially when chunks of paint landed in my clear coat...)

Also, since I had to look up MEK, here's what I found:

en.wikipedia.org/wiki/Butanone

"Butanone, also known as methyl ethyl ketone or MEK, is an organic compound with the formula CH3C(O)CH2CH3. This colorless liquid ketone has a sharp, sweet odor reminiscent of butterscotch and acetone. It is produced industrially on a large scale, and also occurs in trace amounts in nature."

DoubleDub wrote:

When you say "use", what exactly is the process? Do you just pour some MEK into the cup and spray it out? What do you use to determine a state of clean without disassembly?

EXACTLY

Once I have done this and the MEK comes out completely clean I put a couple of OZ of MEK in the cup and just let it sit. In guns that get used daily or even weekly, they sit with MEK in them all the time. With non metallic paints this will pretty much keep the guns clean. With metallic paints the final few rinses I shake the gun vigorously while I spray the MEK threw it. Make sure that you are in an area that flying MEK will not ruin anything.

Thanks, Otakar!

Now, the hard question. If the gun does get abused and there is solidified paint of some degree in the gun, what's the battle plan?

Do you just have to pick at the internals it until it all seems to come out (which is what I did to try and clean mine)?

Considering my gun is a cheapo China job, I probably could have just bought another one rather than mess with cleaning, but I'd rather learn to clean a gun properly on a cheapo than ruin an expensive one.

Is MEK something that can be bought from a paint supply or other retail establishment? Any idea if the Canuck's would be able to buy it (since Mark started this thread)?

DoubleDub wrote:

Also, since I had to look up MEK, here's what I found:

en.wikipedia.org/wiki/Butanone

"Butanone, also known as methyl ethyl ketone or MEK, is an organic compound with the formula CH3C(O)CH2CH3. This colorless liquid ketone has a sharp, sweet odor reminiscent of butterscotch and acetone. It is produced industrially on a large scale, and also occurs in trace amounts in nature."

MEK is available at ALL paint stores and almost any and all hardware stores. It is one of the most used solvents and belongs in the Acetone family of solvents but unlike Acetone itself MEK is not Hygroscopic. This is why MEK is preferred as a substitute for Acetone in painting, because it eliminates a phenomena known as "Solvent Pop", which is common in drying paint and can make paint look like it has sand in it.

I also use Harbor Freight "Chicago Pneumatic" paint guns and piss of a lot of so called "Professionals" because i can do the same thing with gun for $19.99 that thy do with a gun for $300. If a "non activated paint" drys in the gun, than KEK will dissolve it for any future cleaning. If a two part paint cures in the gun than it is simpler to junk it and use it for parts.
Ask Old Man Rock, what he thought of my paint job done with a $19.95 Gun. This is the gun I painted the bikes in the following posts with.

www.harborfreight.com/20-oz-5-cfm-gravit...spray-gun-91009.html

And this.

Closeup

You can find out more about the paint job here.

kzrider.com/index.php?option=com_kunena&...w&catid=11&id=169462