How Do You Properly Clean Gun After Spraying Gelcoat?

General Composites Discussions Equipment Talk
#1

Hey guys,
A long time ago, the local composite shop sold me an LVLP gun with a 1.8mm tip, which they recommended to shoot tooling gelcoat for the small parts I was trying to make a mold of. I’ve made 4 molds now by brushing, but want to make use of my gun since it sits there looking at me. My question is…

After each layer of gelcoat, what is the proper way to clean the gun before the gelcoat sets? Cleaning the cup is obvious, but how do I go about cleaning out the internals of the gun? Do I just remove the tip and soak it in acetone? Do I just pour acentone in the cup and shoot it out into a container?

Thanks in advance

#2

I use acetone and shoot this through the gun about 3 or 4 times along the way cleaning also with a rag etc. Spray onto a big piece of carboard or box etc.

Then when your happy it’s clean and sprays or trigger flows clear acetone you just leave some clean acetone in the cup with the main air tip (the outside part) or paint tip (part inside behind the air tip) too if you wish. I am not painter so these are probably not the technical terms for the gun parts??

It still builds up inside the resin/paint tip part if you leave it on a while (days, weeks?)so from time to time you need to poke at that to clean it out.

Once in while to give a gun a good overhaul you clean it with brush on paint stripper and tooth brush etc to give it a birthday. Wear eye protection, it burns!

Before you start a new gel job always test/check your gun with a solvent before you mix material so you are sure your gun works first! If not check it and fix it.

#3

Thanks fasta. I shot my gelcoat once and don’t think I would do it gain until I get a gun with a larger tip. Too much overspray and wasted material. Gonna go back to brushing for now.

But I heard to not shoot acetone through the gun? I just cleaned the cup quickly. Threw the tip, needle; basically everything except for the body of the gun and cup into acetone and scrubbed quickly.

#4

If acetone does any harm then I have been doing it wrong for 25 years and never noticed!

For specific spray gelcoat you will probably need min 1.8mm tip up to 2.5mm tip.

If you think gel coat and spray guns are a pain then wait till you try a pressure pot. Not fun.

#5

I use a dump gun, since it’s dead simple to clean… Clean the cup, clean the lid, wipe the gun. I think I have a 1/4" tip on there…