I am a hobby painter, but I paint quite a bit. Like once or twice a week. When I first began painting, I was lazy and basically just sprayed lacquer thinner through the gun after using it. When I next used the gun it would always be balky and dysfunctional. I eventually learned my lesson. When you finish painting with the gun, disassemble and thoroughly clean the gun immediately. When shooting mixtures with hardening/catalyst agents, it won't take long for the gun to become "dirty". I own 5 guns of various styles and price and they all can be completely disassembled, including tip. Most guns come with a dissassembly wrench tool and a set of instructions. They both come in handy. Once you completely disassemble your gun ( don't be afraid of it ) , it will become easy. Just about any auto paint supply outfit sells gun cleaning kits for less than $10.00. Get a set of brushes that range from tiny to large. Get a set of cleaning picks that cover the range of sizes. These will allow you to clean out the vent holes and passsages, etc. If you clean your gun immediately you can get by with lacquer thinner or reducer. If you let the crap set up, you have to get drastic and use "SprayKleen". Make sure you wear a set of heavy rubber gloves throughout this process. While you are at the auto paint store, pick up a couple of extra mixing cups( quart size ) and use these to soak parts in. After cleaning your gun and reassembling leave a small amount of lacquer thinner or reducer in the cup. This will prevent any leftover from setting up. It's a nice feeling to pick up a gun when you want to paint and be ready to shoot. If you don't discipline yourself to do this, you will have an endless chain of " disposable guns".