Losing the battle tonight with my airbrush and AK Interactive Matte Varnish #775 (ACRYLIC)

1) It's won't do any harm to the airbrush & is quite a normal / regular thing to do. Is it possible that when back flushing some paint got from the cup into the  trigger area & consequently onto / into the air valve?

2) haven't used AK

3) Strong solvent / cellulose thinner is an excellent cleaner, but shouldn't be put near any seals that aren't PTFE (PTFE seal are white, others are black) as it will swell & eventually deteriorate them - If I have an issue & suspect it's paint blocked somewhere I will strip the nozzle & air cap & soak these in cellulose thinner. Regular airbrush cleaner or isopropyl alcohol should be fine for the rest of you cleaning.

4) Just like airbrushing anything, thinning & drying can be a problem.

It sound's very much like you are suffering from tip dry - reducing pressure and/or adding a retarder will help to avoid tip dry, AK do their own brand retarder "AK Interactive drying retarder"

Let's not forget the needle pressed too much to the tip - thus closing off the airflow. I agree with above poster regarding the seal but I find it hard; yet doubtful the seal going bad after 4 months of use.

Couple of things.. 20 psi seems like a lot but might be all right just experiment with it. I almost never look at my gauges they lie anyhow.

Do you have a dryer / filter in the air line?

Many matte laquers do not require thinning and in fact warn against it. Too much thinner and the stuff dries out before it even touches the intended surface and as you found out will collect on the tip making a mess of things. Once it does get a glob on the tip, just pinch it off with a damp cloth and fingernails. Careful of course not to bend.

What was the humidity / temperature conditions when you were trying.

Good old laquer thinner from the hardware store works well for cleaning. Also get a set of brushes intended for the task. As mentioned before do not let it sit in the thinner sit overnight as it can get after the plastic parts in there.

Backflushing is actually a good idea. I do it after every color change / cleaning.

A side note, I hardly ever break my airbrushes all the way down for cleaning. In fact I consider withdrawing the needle a drastic action. If I do get tip dry I simply 'pinch' it off with a damp cloth and fingernails. I also keep an old tooth brush handy to clean the face of the brush occasionally.

Invest in some quick disconnects. You will thank me

Maybe once a month or every other month do I do a full break down of the brushes.

Thank you for the replies and help. Yes, my compressor has a water separator right on it. I first tried spraying the Matte varnish right out of the bottle, as it seemed to be a good consistency to spray out of an airbrush, and it said right on it "brush/airbrush". I do have a quick disconnect for the brush from  the air line.  When I tore it apart, it seemed as if the Varnish had turned to mucous-y thicker snot consistency, and that is what was clogging the brush. I could occasionally see the stuff coming out between the brass nozzle and the needle, but by the time I discovered this snotty stuff, the air valve was stuck wide open, and it seemed no amount of thinner and cleaning was helping it. When I finally destroyed the chrome finish taking the air valve apart, and cleaned it on the inside, it worked for a couple sprays, then the air valve got stuck wide open again. It also had a minor air leak after I put it back together, and the brass Allen screw that is the bottom of the air valve promptly stripped out as well.

Needle was not too tight into tip, moved freely. Humidity was low, inside the house with the AC  on. When it did spray, it would sometimes spit foreign stuff out with the clear. I had sprayed flat black Testors acrylic paint right before, and the brush worked fine......

Anybody else? Seems like I've had way too much trouble for spraying expensive "varnish" that should be ready to spray right out of the bottle, after a good shake. On a side note, the spots where it did spray, were flat just like the paint, and you cannot really even tell where it was varnished/unvarnished. I like the results, but the spraying was a major PITA.

Thanks, Rudy

Rudy I don't know what else to say other than it sounds like maybe you had a bad batch of varnish or it was thinned incorrectly, maybe you had a little water in the brush from prior cleaning, maybe there was some water in the mixing cup, hard to say.

I thought about the back flushing comment and forgot to mention its a good idea for gravity feed brushes but not so much for siphon feed.

ps; I really don't think the air valve assembly is the culprit unless it was bad to begin with. I don't think I have ever removed an air valve... ever.

Thank you for the responses UlteriorModem...  I am not sure why the air valve decided to take a dump, but I don't think the gooey varnish getting in there helped at all. Im hoping the new parts should be in today, so I can finish the job and post some pics of the plane, IF you guys promise to take it easy on me;) I also have a bottle of Vallejo matte varnish.... Not sure if that is the same company or not, I cant keep track of the mergers, and people breaking off, etc....

Thanks again, Rudy

I have a small bottle of the Vallejo varnish but have not tried it as yet.

In the meantime I have been using this stuff

www.amazon.com/.../ref=sr_1_1

With decent results. Long drying time though 12 hours between coats is recommended.

Rudy, just wanted to touch base to see if you were able to solve your problem with the Talon?  I just ordered a Talon for myself and wanted to see if anyone had any comments about the performance.  I have been using a cheap Master dual-action as my first airbrush for the past year.  I didnt want to go out and spend a lot of money on a good quality airbrush until I knew I would be able to use one.  Do you have any pointers or tips that I should be aware of?

Rudy

Was this AB brand new? It sounds like the needle bearing seal was bad and allowed paint to leak back into the trigger and air valve. The same thing happened to me with a brand new Badger Patriot. The needle bearing also went bad in my Badger Renegade which was sent back for repairs. The paint leaked into the rear of the AB making the trigger stick and the air valve jam up.

If its new I would either take it back where you got it or see what Paasche's warrantee says.

For the down time, I purchased an Iwata Neo at Hobby Lobby with a 40% coupon that cost me $47 and I'm very impressed at how well that inexpensive Neo performs. The trigger is silky smooth, the  paint chamber design makes it a snap to clean and it produces fine pencil lines at low psi.

In my experience, Vallejo & AK don't spray well.  I have to really work hard to get them to spray well.  So I no longer spray them.  In contrast, Tamiya & Testors acrylics always work for me regardless of the thinning ratio and regardless of psi.

For some reason, MM acrylics don't spray that well for me but the Tamiya paint seems to spray almost as good as enamels for me. I have several Vallejo paints for hand brushing and have heard that they do not spray well with the exception of their Model Air line.

WHEW what a PITA you're having Rudy.

I empathsize with all your AB problems.   I have a Badger Patriot ( my main AB )  a Pasche VT and a no name cheap one from Harbor Freight and none of them has had the problems that you are experiencing.

I always use Testor's Dulcoate/Glosscoat for my clears.   I always run 2 cups of hardware store laquer thinner thru the brush after painting and only occasionally hafta disassemble for a thorough cleaning. I have not had any problems with the seals breaking down with the laquer thinner.

Seeing the problems you've had with AK , I'll stick with the testor's and thank you for the informative post.

I've never had problems using Model Master acrylics with an airbrush. Maybe you're not thinning it enough or thinning too much.

Rudy, bet there were forehead marks on the wall.

As mentioned, backflushing won't hurt the A/B. It does however put air into it, which will accelerate the drying process.

I don't think you got a "bad" batch of varnish, that's usually just a problem from aging paints on the LHS shelf and I can't imagine that your AK Varnish is old.

I am going to guess that humidity is a factor, which you can measure by how often you empty the water trap. The house A/C won't have an effect on that.

I dindt have any issues with the MM acrylic paints, they sprayed fine. It was the AK Acrylic "matte varnish" that gooed everything up. It was the 4th time using the airbrush, so I am really not sure what the issue was. I ended up using an ez-out to remove the broken nozzle threads, but there appeared to be some left in the brush, and with the long (too long really) EZ-out, it appeared I tore up the inside of the brush a bit. My impatience I guess, Paasche said to send it in and they would replace it. I had already tore it up at that point, so I just bought a new one. (like I am "made of money" or something?!?) It really isn't that bad, it ,may seal up and spray fine, but I didn't want to risk it. Oh well, now I have extra parts :) Paasche customer service was quite friendly and easy to work with. I went with them for being "made in the USA", I am not sure if Badger or which other makers are as well. Hopefully I wont have anymore issues, I'd like to find an acrylic flat "clear" that sprays well. Thanks for all the help and info-

 Thanks, Rudy

I use Model Master acrylic clear, thinned to about 50%, and it sprays wonderfully with about 20lb PSI. Seriously, give it a shot.

Thanks Karl, I'll give it a shot. I have used the MM Lacquer flat clear, but it seemed a bit "glossy" for my liking....