A couple of days ago I remarked that I was seeing little flakes of what looks like brass in the paint, in fact after spraying the A-7D there were a lot of these flecks present. Initially I put it down to maybe the coating on the inside of the paint cup on the Iwata Revolution CR that I used, however thinking about it today I bolted an external air tank to my compressor years ago and if it doesn’t get drained of condensation regularly you get a pool of rusty water lying on the bottom.
To test this theory I returned my Iwata Smart Jet compressor to its original factory spec (bypassing the air tank) and using the Iwata I suspected of shedding metal, I sprayed a test piece with Tamiya XF-1. Afterward I couldn’t see any evidence of these flakes so maybe the tank was the problem, either way I’ve removed it as it never seemed to hold enough air as the compressor always seemed to be kicking in during a spray session anyway. The whole point of fitting it in the first place was to reduce wear and tear on the compressor by holding an adequate supply of air but the tank never seemed to.
I’ll keep watching for flakes in case it wasn’t the tank however if it proves to be the airbrush I may as well get a new one as a replacement body alone is around two thirds of the retail price.
Andy King's Model Blog 
Hi Andy,
I have been reading your blog for the last few weeks, and I am finding it interesting to hear of the things that go wrong! I am glad it is not just me. I have just read your possible compressor problem, and I wondered where your regulator/moisture trap is? If you fitted an extra tank to the system, should the regulator not be between the tank and airbrush, and so filter out any muck before it reaches the airbrush? I am only mentioning this as if you fitted the tank after the regulator that would explain why the tank never seemed to stop the compressor running as much, and also why the muck is reaching the airbrush. Hope that’s helpful, and I’d be interested to know the answer, I’m always thinking about ways to tweak/‘Improve’ cheap airbrushes (usually making them worse) and building compressors from old fridge compressor pumps ( made one, and it actually works!)
Regards,
Andy
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Hi! I think you are correct on all counts regarding where the filter was, why it wasn’t filling up etc. I’ve removed the tank anyway as the amount of rust I found was pretty horrible when I vented the excess water out of it.
I’m glad you are finding my blog of use too :o)
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Hi again Andy,
Glad to be of help. As well as the filter on the regulator I also have one of those small inline filters fitted to the end of my air hose, just before the quick-fit connector as extra insurance. I have never seen any moisture in it, but I don’t take any chances! All compressor tanks seem to fill up with rust, it’s best to vent them after each use I think ( that doesn’t mean that I remember) just let the pressure off to 10-15psi, then loosen the bleed valve carefully. All my compressors have been second hand and I have even got a couple of cheap Sil-air’s from eBay ( they run from fridge type pumps and are very quiet) I checked one recently, and the rusty sludge was terrible. So it’s in pieces now after I flushed it out, treated the rust and poured a tin of Hammerite into it. I had to slop the paint around a bit, then poured it out. It took ages to dry, but I now all I have to do is remember how to put it all together again. So, don’t write off your tank yet, it could be worth cleaning it out and reconnecting it before the regulator.
Regards,
Andy
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Yeah I have an in-line filter on the hose too
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