Water Based Gun and Hose Flushing

Advice on cleaning solutions for gun and hose maintenance when using waterborne formulas. June 17, 2010

I have just begun using waterborne lacquers in both my gravity feed gun and my pressure pot. I find this stuff sticks to the linings of the gun and hoses like peanut butter does to the roof of your mouth. I currently just use hot water to flush the gun and pressure pot setup and then leave the gun, pot, and lines full of water when not in use, but this really doesn't seem to get it all. What do you other water based users do to clean your equipment? Is there a chemical that can be sent through to really help flush it out?

Forum Responses
(Finishing Forum)
From contributor M:
I don't use waterborne lacquer, but do on occasion use waterborne enamels and such. I do my first cleaning with water, as that is one of the advantages and it's less expensive. My final cleaning I use lacquer thinner and usually leave some in the guns. (I use a couple of cup guns and pressure pots.) When I leave water in them, I find a little gooey residue and some tarnishing of the metal. Before next use, I remove the lacquer thinner and let air dry a few minutes, so that I don't mess up my next batch of paint.

From contributor J:
I usually rinse with warm water and run some through the gun. If it will set longer than overnight, I dump out the balance of the water, add some acetone, run some through the gun and leave a small amount in the cup to displace the water. Make sure you rinse it well before using again. I find when it really gets heavy, a good soaking overnight in the acetone usually takes care of it, with a little scrapping.

From contributor K:
Soapy water with a little ammonia added cleans it just fine. Rinse well and run DNA through it if you want. Also make sure you are using guns with stainless steel parts (if not, you must run DNA or acetone through it).

From contributor N:
In my experience warm water is only half the battle. If I don't follow up with a rinse of DNA I won't get it all.

From contributor Q:
We spray all waterbourne, an HVLP as well as a Kremlin air assist, and we clean with a mix of hot water and ZEP floor stripper (15:1 or so). Whenever we need to soak any parts it cleans great.

From contributor R:
M.L. Campbell has a new waterborne Gun and Line Cleaner Concentrate (product number is GLC10) that gets mixed 10:1 with water. It works well and keeps things clean. Keep it charged in your line overnight and flush with water the next morning. It is real cheap when you consider you get 10 gallons out of 1 gallon of stuff. Water and most solvents just do not work well and you always get buildup.

From contributor D:
DNA and IPA will both work very well, as will acetone. I prefer the first two, along with water. I also have a parts washer with which I use a combination of water and Simple Green to clean my cup guns.

From contributor A:
Fuhr 333 cleaner works great. Very strong, needs to be diluted per instructions on can.

From contributor W:
Diluted Simple Green has always worked fine for all of the waterbornes we've used. Denatured alcohol for stubborn stuff. Acetone for the stuff that wishes to stay permanently. The solution to pollution is dilution. I usually fill up the cup of a gravity gun 75% full with water and shake it. Pour that out. Then run a 1/2 cup full of soap water followed by a half a cup of clean water.