RichardPrice Posted May 17, 2014 Share Posted May 17, 2014 Having spent the past couple of weeks trying out my new airbrush (Neo Iwata), Ive finally had some good results with a 30/70 mix of Ultimate Products thinner and Humbrol acrylics at 20psi, but I have a few questions... Firstly, although I'm getting good even coverage, very very occasionally the airbrush is spitting large droplets rather than a fine spray. I'm also seeing a build up of paint in the nozzle protector at the very front of the airbrush, outside the nozzle. What am I doing wrong (if anything)? Also, I'm setting the compressor to 20psi, but is the pressure I'm after the static pressure the dial sits at when at rest, or the pressure the dial drops to when the airbrush is in use (seems to be 5 psi lower than the static reading). Thanks for any answers. Link to comment Share on other sites More sharing options...
viscount806x Posted May 17, 2014 Share Posted May 17, 2014 Richard, just an idea but I have found Humbrol acrylics to be a bit tricky and all acrylics to be trickier generally than enamels though doubtless many will be hitting the qwerty shortly after me posting this to dispute it. Seriously though, if you are new to it, I suggest have a few goes with enamels first, thinned to about the same as milk. 15 psi should work fine or even a bit less. Have a white spirit soaked tissue handy to give the business end of the 'brush a wipe now and then, to prevent the build up you describe, and strip and clean it all afterwards. THINLY lube up the seals and needle with that excellent airbrush lubricant in a small tube (sold by the Airbrush Company and no doubt others) and you will be ready for next time. Hope this helps a bit. Nige B. Link to comment Share on other sites More sharing options...
justin1980 Posted May 17, 2014 Share Posted May 17, 2014 Hi Richard, I use Revell acrylics, thinned with tamiya thinner around 50/50 and spray at 20-22 PSI, thats the pressure that I set on the dial, spray a couple of bursts of air and my compressor dips, so I reset at 20-22 and although it continues to dip when spraying it should return to the set pressure, thats quite normal. When I started I was having the same issue as you, fine spray, stop spraying, when I started again I would get large droplets and few large splodges. I started adding Winsor and Newton flow improver to the mix and haven't had an issue since. No dry tips, blockages or splodges. I would also suggest trying more thinner to paint as this may help too. Just did some checking as I remember seeing a mix ratio guide for Ultimate as I have some and found it on the review thread, http://www.britmodeller.com/forums/index.php?/topic/234956555-ultimate-acrylic-airbrush-thinner-cleaner/?hl=%2Bultimate+%2Bairbrush The mix chart is down the page a little. It recommends 50/50 mix with Humbrol acrylics. Hope this helps. Link to comment Share on other sites More sharing options...
RichardPrice Posted May 17, 2014 Author Share Posted May 17, 2014 Thanks Nige, the rag tip sounds like something worth doing, but I want to stick with acrylics for the moment purely for the drying times involved. Justin, thanks for the tip about the flow improver, I shall give that a go - however, I did try the UMP ratio first off and all I was getting was a very runny spray, with streaks on the model where it was running tried a few other ratios and eventually settled on the ratio I did. Link to comment Share on other sites More sharing options...
justin1980 Posted May 17, 2014 Share Posted May 17, 2014 Hi Richard, The next thing to try is changing the psi, the thinner the mix the lower the psi, so for your 70/30 mix I would be tempted to up the pressure and see what happens. Link to comment Share on other sites More sharing options...
Shermaniac Posted May 17, 2014 Share Posted May 17, 2014 Have you got a moisture trap on your air hose (somewhere)? If you have, purge it occasionally, if you haven't, may I suggest you get one soon! Does your compressor (you do have one?) have a reservoir tank and is not a direct feed? On Paint: Personally I use Vallejo Acrylic - I know , I bang on about it - but it is FAB stuff and quite forgiving also, loads of colours. ALL paint will clog up occasionally but if that is the case apply a bit more thinner. The paint should always be warm, but if the room is too warm you wind up spraying DUST! I mix 60% paint to 40% thinner for the model color and 80/20 for model air - if it starts to get a bit claggy I add a couple of drops of airbrush cleaner and mix it in - it's like giving the airbrush a laxative, after a couple of minutes - watch out! Link to comment Share on other sites More sharing options...
RichardPrice Posted May 18, 2014 Author Share Posted May 18, 2014 (edited) Hi Justin, I shall play around with the psi and see what happens! Shermaniac, yup I have a compressor with a tank and it has a moisture trap Edited May 18, 2014 by RichardPrice Link to comment Share on other sites More sharing options...
Rizzo Posted May 18, 2014 Share Posted May 18, 2014 I always had this trouble when I started with my airbrush. Problem is that the air forms water droplets while it's in the air line, and past the moisture trap. I got an inline filter, and never had the problem again. Here's the one I have: http://www.hlj.com/product/ATXHGF/Sup Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now