No!

L'll agree with B---. While my own first choice for air line is copper, steel (galv or not) should work fine with the proper filtration. It is, after all the mainstay choice for compressed air and has been for many, many years. I have no idea what the micron rating is for those little line filters that you put at the gun inlet - I don't use one at all. Also a water trap is not a filter. If your problem is particulate matter originating somewhere in your piping system, water traps are not the solution. A "standard" particulate filter for painting from DeVilbiss is 5 micron. A similar one from Sharp appears to be 10 micron. These are in combo filter/regulator units. I wouldn't expect them to be wire mesh but I have never peered inside of one. Usually that type of filter has replaceable elements and is not like the cleanable oil bath air cleaners that you see on engine intakes. I don't know if what you have is something similar. The triple filtration unit you mention will be about the best you can get, although I'm not sure it is necessary. I have something similar (40 micron/1 micron/0.01 micron) but I suspect it is overkill. Certainly if you go with a coalescing filter (typical 0.01 micron), you need at least one coarser filter (prefilter) upstream of it or the element could be clogging all the time. Fine filtration is almost always done in multiple stages, as a practical matter. Before you do anything however, try what B--- suggests regarding tearing into your filter at the gun for a visual inspection - just to check things. I suspect it's cheap enough to be considered a throw-away. Also try and find out what the micron rating of it is. If it's 20 or 40 micron, you may be getting finer stuff right through it anyway. If you are getting the finer stuff through, there probably are larger particles also that will be caught and will show up on a visual inspection - if the problem is originating somewhere in your plumbing system. I still think it is some kind of atmospheric contamination. If that's not a typo down below and you really do not use tack cloths just prior to paint, you should. That's pretty standard practice. I see recently somewhere (maybe DuPont) that sells tack cloths that are also treated with an anti-static material. They would seem to eliminate the extra steps of spraying an anti-static product. That may not be your problem but I just mention it in passing.

Rod

• RTI

Rod

• SW

B--- brings up (up above) an interesting hybrid situation of foreign particles contaminated with oil/silicone, thereby taking on the appearance of both dirt and fisheyes. I don't know. I think it is dirt of some kind. Have you attempted to use any kind of magnification for a better visual of a typical spot? Both before and after sanding. I am thinking if you could possibly identify it as some type of foreign matter that way, it would eliminate the solvent pop from further consideration - at least I think it would.

Rod