Helpful Tip : FISH EYES OR WHATEVER

[stevedwnng]

I noticed some dirt specs on the finish of a valve cover I did. I disassembled and inspected everything and couldn't find the cause. I'm always careful about keeping my gun clean, probably to the point of overboard. I took the air fitting off my air hose and ran a q tip down into the hose and it came out dark brown. I went out and bought a brand new air hose, a new water separator, moisture separators, and some in line desiccant air dryers. I also cleaned all the fittings and couplers out. I also went one step more and tried again using another compressor. Instead of using my old 220v monster that has some worn rings (oil blowby) I used my dads little 1/2 hp oil less compressor. The following pics are the results. Fisheye everywhere. I didn't spray any silicone anywhere, baked the part at 450 for over an hour, thoroughly blasted the part, wiped it down with acetone until dirt would no longer appear on the rags, and did the water break test, ect. The rags are brand new micro-fiber towels that I cut into pieces and there are no chemicals in the towels. I've used them before with no problems. I applied iron phosphate and rinsed thoroughly before putting the part back in the oven to bake off any residual moisture before applying powder. I can't for the life of me figure out what is causing the fisheye. Here are some pics. Any ideas guys? I hope it's just something I'm overlooking.

[Harleydad]

Still surface contamination of some sort. It seems as though you have taken steps to eliminate the air supply. Have you cleaned your oven lately? After the outgassing who knows what floats around in there.

[stevedwnng]

I clean the oven with a tack rag to pickup the dust and stuff that collects on the top of the oven above the burner elements. I think that when i was using the old air line, it blew oil into the powder in the cup. When I put the left over powder back in the bottle it contaminated the rest of the powder.

[Harleydad]

Originally Posted by stevedwnng

I clean the oven with a tack rag to pickup the dust and stuff that collects on the top of the oven above the burner elements. I think that when i was using the old air line, it blew oil into the powder in the cup. When I put the left over powder back in the bottle it contaminated the rest of the powder.

Entirely possible

[stevedwnng]

Well the good part of it is, I used the last of that powder when I did that. The color partial cured with no problems, but the fisheye appeared when the clear started curing. I used the last of both of them on that piece so I just ordered new powder. I'm going to do another test piece with another powder and see what happens. Is there a fisheye eliminator additive?

[moonstruck60]

well steve, what did u find? i am sure u have gotten ur new powder and clean cup and gun, did that help u?
moon

[stevedwnng]

Yes I did. I actually coated with the new powder today and it cured perfectly. It's time to invest in a professional grade air dryer system though. I heard some where that some people have incorporated old window a/c units into their air system in order to eliminate humidity. The cooler the air, the less there is a chance for humidity. Anyone heard of this?

[darrellwaldner]

Does dust particles and dust contamination pose as a major problem after the part has been cleaned?

[o1racing03]

Originally Posted by darrellwaldner

Does dust particles and dust contamination pose as a major problem after the part has been cleaned?

If theres any static in the air any dust or trash floating in the air can be attracted to your substrate. when your part is hanging and you spray you could be causing air flow to blow the dust bunnies onto your parts. It could be coming from the ceiling ,your clothing or just floating in the air.

[darrellwaldner]

Originally Posted by o1racing03

If theres any static in the air any dust or trash floating in the air can be attracted to your substrate. when your part is hanging and you spray you could be causing air flow to blow the dust bunnies onto your parts. It could be coming from the ceiling ,your clothing or just floating in the air.

thank you... see we have shop and dust collection is everywhere, and with a large shop its really hard to avoid, i was wondering if that was the actual problem with contaminated parts.