I don't know why I feel the need to apologise for this post, and I have gone back through the forums and looked for the definitive solution to this, and you know... it just can't be right can it, but . . ? etc.

I tried using Model Air to do some airbrushing that required some degree of accuracy and subtlety for the first time yesterday, doing a three colour soft edge camouflage freehand, so admittedly not the easiest thing to start off with, but I assumed that in using Model Air I was using a paint that would work prefectly in an airbrush. It now seems that I was a bit rash. Eventually after much tutting and a little swearing - and a sore trigger finger - I got a result that was OK, but it was a bit of a struggle.

It seems from looking back over some threads that I am not the only one to have found the very fast drying time of this paint just a little too fast, in that it seems to me that the nozzle clogs with semi-dried paint after a pause of as little as 5 - 10 seconds. If painting large areas, say a base coat, where you can start spraying off the model and move on to it, it's not really a problem as pulling right back on the trigger, releasing a lot of air and paint, blasts the blockage out, but when wanting to start spraying with a fine line on the model itself I found that moving the trigger to the position where I thought paint would start to come, a lot of the time I got nothing.

So cleaning out the nozzle, or giving a big blast of paint into the air before starting on the model, is an approach, and is what I had to do, but it more or less treats the symptom, but doesn't seem like a solution that effects a cure.

So is there a solution? I tried using some Liquitex retarder in it, but maybe I should have used more; I'm conscious that someone may say, you need to use Vallejo retarder, but then again, the instructions that come with the paint don't exactly state that is a necessity.

For some reason I also ended up with quite a lot of extraneous spray dots around the area I was spraying, rather than getting a nice subtle scale-looking spray line, like it was all a bit coarse looking. I may post a pic if anyone is curious.

Mathew,
I am curious what paint you were using before this experimental move to Vallejo Model Air?
I would say that this is part of adjusting to a new medium & hopefully you will find the paints pleasing after you have had a chance to work with them. A very small drop of tap water can help with this as well as using Vallejo's retarder. I do not know if it is different than Liquitex as I have never tried this product but I can say that the Vallejo retarder cuts down on the drying time and helps prevent this drying on the tip.

I am not sure as to the cause of your problem. I have been using Vallejo Model Air for about 6 months, and have not experienced that problem. I am using a Paasche VL and Iwata Eclipse. I have painted both larger areas, shooting straight from the bottle @ 20-25 psi, and I have done free hand camo, thinned with either Tamiya Acrylic thinner or Vallejo thinner at about 15 psi. I do keep a Q-Tip wet with airbrush cleaner near by, and occasionally clean the tip off. I used to use an Aztek airbrush and had tip drying occur regularly, regardless the acrylic paint I used. I am not sure what to tell you, maybe try keeping the Q-Tip handy and see if that helps.

Iain, generally Tamiya, thinned with their own thinner which always seems to work fine, but I've used Liquitex soft body acrylics thinned with their own airbrush medium for the base coat on this same model - and for that I had to filter the paint (with a little cone of tea bag paper shoved in the paint cup) to stop particles from clogging the filter.
Only drying problems I'd had previously was the Tamiya mid-air drying causing rough finishes due to thinning with alcohol instead of their thinner, though never much problem with that drying on the tip. The Vallejo Model Air certainly doesn't seem to suffer from that mid-air drying syndrome, more just premature thickening.

Kevin, I take what you're saying about the air pressures; unfortunately at higher pressures the blockage was more easily overcome, so I ended up winding the pressure up - not really what you want for fine work, and maybe that's why I got the speckly spreading. That's what I mean by the paint seeming to thicken on the nozzle rather than completely drying - I could blast through it with sufficient air, but at low pressure I just got the bubbling in the cup routine.

OK, a quick update to allay any fears that anyone may have on my behalf . . .

I had another go last night, and everything seemed much better. The same paint (Tank Brown) with approx 25% Liquitex Slow Dri - in fact it was 14 drops paint to 3 drops retarder, except the hole on the retarder bottle is bigger, and so are the drops. Pressure at 25psi was causing a bit of spreading of the wet paint on the surface, but 20psi worked well.

So no splattering to speak of, no over-size paint dots at the spray edge, nice fine pattern, was able to start off on the model, and didn't have to swab the nozzle once, just needed to give a bigger blast on a couple of occasions to get the flow again, but that was over a period of an hour.

Perhaps this may help someone else, even if I seem to have just answered my own question . . .

Do you get a glossy finish when you add the Liquitex Slow Dri? In the bottle I have of the stuff it states that the finish may come out glossy after adding it to the paint. Any truth to that?

Thanks.

Rob

I add a couple of drops of Vallejo satin and mix it all up.. It will slow down the drying a lot. .It also has the surface ready for any pin washes or filters that you might want to do. I have been doing this for the past 3 or 4 years and have had great success. Hope this helps

Hi Rob, no, it definitely didn't come out glossy, it is satin, but not overly so. The prodcut info available from the link above says the finish is satin, but I guess it partly depends on the finish of the original paint you're adding it to - and I have to admit I don't really know what the normal finish of pure Model Air is like! From what I can make out however, acrylic paint is never 100% matt in the way, say, that Humbrol Matt 67 is.

Thanks for the feedback, Matthew. I'll have to test Model Air a little more after I get my current project done to see if it comes out better. My initial tests with this range didn't yield very impressive results. I'm hopeful I can make it work.

Rob