Hi Joe,

If your airbrush is operating correctly, you should never see air bubbling in your paint cup regardless of your paint type and viscosity. Test with plain water in the cup.

Check to see that the nozzle seat is clean and that the rear cone of the nozzle (which sits in the nozzle seat) is also clean. Also, check that the air cap (which holds the nozzle in place) is tightened sufficiently. Gently tighten with the supplied wrench, but (important) do not over-tghten as you may damage the threads.

I had a similar problem the first time I used Vallejo Model Air.

I am using a Harder & Steenbeck Evoluition which is a two stage brush. I tightened the nozzle up to the main body & that solved the problem. If you have continued problems I would try a new seal on the nozzle bit.

I have started using Vallejo on the model I am just finishing at present. On the previous one my first I used Humbrol Enamel. With the enamel I found that the brush cleaned very well with enamel thinners.

With Vallejo I found that it dries pretty quickly. So I make sure that I clean immediately after I have finished brushing. The other night I left it 5 minutes & it did not like that. I had to dismantle & clean. There was a lot of build up on the end of the needle.

A good tip which I got from another forum was to use windscreen washer & this has worked perfectly except in the above case. Two cups full including spraying the nozzle end a couple of times. Then repeat using just clear water.

A few things I have not had to thin Model Air.  Vallejo recommend 20-25 psi air pressure.

You may have already located this info. But here goes. It is the best info I have seen for paints. http://www.acrylicosvallejo.com/gb/downloads.html  Do not miss the FAPQ's a lot of info there.

Laurie

I have had good luck using Future as a thinnner for Vallejo. I also use a thinner mix of 2 parts distilled water, 1 part Liquitex, and two drops of Future. Both of these do the trick for me.

 When using Vallejo Model Air, you should not have to thin & if you do I would suggest Vallejo thinner or tap water.

 Like our friend stated, they will dry quick. Also, can you post an image of this "dust"....I am not sure I understand and I would like to help as much as possible.

Hi Lain

Thank you for your advise. I will try to post some images, but unfortunately, I doubt I can do so without a macro lens to see the effect. Let me try to describe. I am a technical person by nature, so forgive the engineering like way.  I started spraying down lines with the tip very close to the paper,and close enough to guide the AB along the way with my pinky finger. The created lines were  quite narrow as I had hoped, but I noticed that the lines had some amount of over spray on either side. Imagine a line of thickness L, my first question is, understanding that there has to be at least some over spray, should it all fall within  one or two "L" distances from the original line - I.. if I draw a line 1/8" thick, how far from the center of the line should the over spray not be noticeable? - also , without an image, how about expected over spray? - I am concerned I am not spraying with correct thinness. I have read the Vallejo pain guides and they do say from 0 thinner upto about 25% - which is a wide range. I have read many times about the "thin until the consistency of skim milk" - but without knowing what that is experimental wise, I can't thin to it yet, because I don't know if I have yet to get it correct. - So I am looking for other signs my mixture is of correct viscosity . I am just ge3tting started in this form of modeling, as I have been an active radio control pilot who flies scale - I just could not resist the allure of the plastic models anymore...

Anyway, I will see what I can do to get some images, and continue to ask for lots of help!

Thanks again

I've done two aircraft with model air, and the second came out much better than the first.  A big part of that was simple experience, but also doing some research on overspray problems the first had.  Model Air is very convenient to use and comes in a great range of color sets, but suffers from rapid tip dry out of the bottle.  This was also November with the heat on, so the humidity was incredibly low.  Adding Liquitex airbrush medium as a thinner (it contains a retarder) helped a lot with this issue, as was following a much more stringent tip cleaning process during painting.  If you check the Vallejo site they also recommend cleaning the airbrush tip on a periodic basis while working, as quickly as every 30-60 seconds of spraying.

Getting tip dry will cause both overspray/splatter as well as bubbling due to blockage.  

Others have had really good luck with future, which both thins and adds a leveling retarder.  I haven't tried that yet, but I'll have to see if it gives me better results than the Liquitex medium.  

For my latest model I'm spraying Mr Color lacquers.  Zero issue with tip dry or splatter, but the setup is a pain.  Don the respirator, open the window and set up the exhaust fans, etc.  Spraying the model air is so much more convenient.

Wow! having to clean your airbrush tip every 30-60 seconds while painting has got to be a major pain!! I'd seriously look for some other brand. Lots of other paint choices out there that wont' have you cleaning your tip so often. Check out Gunze, Tamiya, or even Misterkit as i just discovered is a great paint, thin with MM acrylic thinner and paint all day.

Nathan

Guys,

 I have NEVER had to clean the tip of my AB every few minutes like this when using Vallejo Model Air...never. Unless you just let the paint sit in the brush while off doing something else for 10 minutes, this should not be a problem. If it is, all you need to do is to use a damp paper towel to fix on the fly.

I use a Harder & Steenback two stage brush which has interchangeable needles etc.

I started using the Vallejo Model Air with a .4 needle Nozzle & did not have any problems at all. But I did strip down the airbrush about every 3 times to give a good clean. The only build up of paint on the needle was about 5mm down from the point. No blockages at all. Used the paint straight form the bottles undiluted.

By chance yesterday I decided to try the .2 needle & nozzle for finer work. Trouble very quickly & had to strip the brush twice. Each time there was paint stuck on the end of the needle.

This morning I tried again but this time I used Vallejo thinners about 20% & this worked well. I was brushing for about 10 minutes without a problem. I stripped the brush at the end & there was some small build up but nothing as before with out the Vallejo thinners. I used in all cases a PSI of 20. Stupidly I did not think of trying a different PSI to see if that made a difference.

Laurie

I just switched from Tamiya to Vallejo Model Air for my airbrushing. I love this stuff as its self leveling properties are amazing.

Some things I have found:

1.) Yes, it does dry very quickly. So make sure to clean your A/B well after each use. One time I didn't and had to  break my Iwata CR Revolution all way down to get the dried up German Grey paint out.

2.) Model Air is designed to spray right from the bottle, but I have found that adding 1 to 3 drops of Vallajo thinner really helps. This is also recommended by Vallejo.

3.) Below is a link to Vallejo's .pdf on Model Air. I use it so much its even bookmarked in my IPhone!

                 http://www.acrylicosvallejo.com/pdf_web/MA_CC071_rev07.pdf

Hope this helps.....

Scott

Totally agree with you Scot a superb finish.

I am on my fourth model now.

At number two on the line I was about to give up. I was using Humbrol & Revell enamel & the frustration of not getting the finish I expected & all the trouble with cleaning & smell were just to much.

Vallejo Model Air turned the tables I started to get consistent finishes & the stuff is odourless. I found that the panel lines were not being hidden. Now I just cannot keep away from modelling.

Laurie

Hi Laurie and Scott,

Thank you for your help and suggestions. I also have been experimenting with the model air thinnner and have even used their retarder. I have settled on a 20% thinner and a couple of small "drops" of retarder ( the retarder is almost a gel, so calling it a drop is a little misleading) - I found concoction lasts me nearly the entire painting session ( bottom of aircraft , etc. ) and I always break my airbrush down and give everything a thorough cleaning - so far, I am most impressed with my ability to apply a clean and crisp paint job, but that is my own opinion on my own work - nothing other than base coats so far. 

Joe