I find that when using either model color or model air form Vallejo the paint dries far too quickly on the tip. AS an example yesterday I mixed Vallejo model color with my homemade thinner (70% distilled water/30% isopropyl alcohol 70%), work great for brush painting. I mixed my paint 50/50 thinner to paint; i could only spray for about 15-20 seconds then the paint would build up on the tip of the iwata even at 30+ psi Suggestions?

I also had the problem of drying Vallejo paint on the tip, but not as quickly as in your case, buying a crown tip for the HP-C did alot to solve this problem for me.

You could also try to use just the distilled water without the alcohol, but with a drop of dishwashing detergent.
I don't know what this exactly does, something to do with breaking the surface tension of the water.

Summer heat could also be a problem (around here it is 30 degrees Celsius) which causes the paint mixture to dry quicker than usual.

Have you tried using the Vallejo Thinner ?

If you check their website Vallejo Model Air - they suggest a ratio of 1:3 thinner to paint.

I also had the issue of the paint drying on the tip (only with Model Air - I haven't tried Model Color through my AB) - using the thinner definitely helped. I think it's more of a "retarder" than a thinner.

Another trick you can try is to add some gloss varnish.

Hope this helps

Peter

I have found that using the thinner, distilled water and paint have worked for me with my HP-B. The ratio I use is 2 thinner, 1 water 1 paint. I also keep a soft brush with Isopropyl handy to clean the tip off if the paint does build up(which it usaully does.

OH, that ratio is for the model air. For the model color I dilute only with water, 3:1.

I have read before that the gloss also helps, but haven't tried it myself yet.

Sean

When ever i mix any acrylic paint i always add a paint retarder it slows the drying time long enough so the paint does not dry on the tip.

3:1 paint to thinner or thinner to paint? thanks for all the suggestions!!

One drop of thinner to three drops paint.