Can someone please help me out.

[Silverlex02]

I am having a problem everytime I switch colors I am getting little spots of that previous colors on the new colors finish. I am cleaning the powder coater really good or atleast I thought I was. Is there a way to take it appart and clean it between uses or is there some kind of trick to now haing this happen. I am about to give up. I apperciate any help anyone can give me.

[Fireblade]

What kind of air pressure are you using to clean the gun? I would use higher pressures, like around 60 to 80psi. Once you think it is clean, do it again. One thing that I noticed when using the hobby guns, was that powder accumulated behind the siphon tube for the powder, then probaby gets into the new powder, due to not getting it out from there. I would recommend even a small bristled brush to get in there and get it all, maybe even up the pickup tube.

[Hemi-T]

I have an air blower that I soldered 18 inches of 1/8" of brake line to. That way you can get high pressure air (I use 165 lbs) all the way inside the static tube and other parts to make sure it is clean. I had the same problem the first time I changed colors. A few specs of the old color in my new project, but not bad. Now I spend more time cleaning the gun when changing colors, and have not had any problems since. Good luck!

Hemi-T

[Silverlex02]

Thanks for the info. I am going to have to check my air compressor. I am pretty sure it is a 100 psi or so, but I am not sure. I am going to have to try using a brush to get in there. I have started to notice that the longest part of this process is changing the colors and cleaning the gun.

[non-stick]

Well.....there's some questions you have to ask yourself first. Are you sure it's from the gun and not surrounding area? I've seen many a tech pull thier hair out until I give a tap on the booth wall and all this green comes flying out when they're trying to do red or what have you. Did you use a vacuum when cleaning everything? With a charged particulate....it all acts like glue when it's flying around looking for a new home until you charge everything up again. Did you use/can you use solvent in cleaning your gun? I don't know about the hobbiest guns...but the Gema-Ransburg models can take a good solvent bath in MEK or what have you if there's any hard crusted particle built up anywhere. Also....how many different colors have you gone through and done this. We have a cute term for what happens sometimes called "powderberg". That is to say....if one of those magical spots that's tough to clean keep getting built up with powder, it accumulates until a big chunk of it breaks off and lands on your part (why does it always happen when you're doing white?). The bottom line is this....clean everything twice. When you've done that....clean it again and seal it in a plastic bag. Keep it clean. Make sure when you coat, the surrounding air in not a whirlwind that kicks up stray particulate. Use a vacuum and plenty of compressed air at a healthy pressure. I know it sounds like it will never fully work itself out...but in the longrun, it will happen and your whites will be pure, the red's won't have that X-Mas effect with green sparkles....and little grief will be had.