Hello,

I started to paint with vallejo grey primer on some 1/35 tank ammunitions before trying on my main project. I tried to thin it with water or tamiya thinner and it dries like crazy in my airbrush. Paint just accumulates at the tip of my needle and I have to fully depress the trigger to do a big splat of paint before continuing to spray on my subject. I run at about 25 ish psi. When I do practice shots on a piece of paper the paint comes out as if it was too liquid (very runny and accumulates quickly on the surface, producing little streams of paint) but at the same time my needle is jammed up in 2 sec. I'm using a grex airbrush with a 0.3mm tip. Any advice ? I'm kind of scared to go further and spray my tank with that primer

Thanks in advance.

Tom,
Not sure what the issue is, I have had great success with all of the primers from Vallejo. I have never thinned any of them however, just used them straight from the bottle and sprayed at about 20 PSI or so with a .3 needle as well. I won't insult you by recommending that you stir the contents well because I know you already did that! You might try a retarder or lowering the pressure to see if that does the trick. Finally, insure the airbrush is good and squeaky clean, I know that most of my problems start here!
Good luck!

Cheers,
Rick

All of the above have been done prior to painting... Maybe I got a bad bottle; I'll try AK primers and see if the results are better.. I'm bummed to say the least about vallejo primers.

I've had off and on results with Vallejo primers. For some reason, I can spray their black perfectly, but the grey just splatters kinda like you said. Granted, I bought the black within the last year and the grey when it first released. They might have changed formulation since then.

I know AK primers went through a formula change. They used to have a smell and go on so/so, but the newer formula is completely odorless and works very well. I recently bought bottles of white, grey, and tracks, which all perform excellently with no odor, easy cleanup, and very little tip dry.

Vallejo primers seem to have their detractors (from what I read from time-to time) but I think the stuff is pretty good. The only downside that I know of is that it does not "bite" into the plastic like lacquer based primers. The first thing you mention that raised alarms in my view is that you thinned it with Tamiya thinner. Only use Vallejo thinners for thinning Vallejo paints and primers. Yes, water will thin it OK but I think the Vallejo thinner does a magnificent job. Tamiya thinner - if you are talking the X20A kind - is essentially isopropyl alcohol which gums up Vallejo paint (why? I'm not sure...but it does). A .3mm tip should be adequate and I spray these primers through my .35mm tip without thinning. The other downside to all Vallejo paints is that they tend to dry at the tip quicker than their acrylic cousins of the other brands. Keep a wet Q-tip at the ready to clean your tip every couple of minutes. So, why go through all the trouble? If applied properly I think Vallejo primers present a superior surface with which to apply follow-on top coats. Plus, if you like to work in only acrylics for safety reasons (and odor reasons) Vallejo is good route to go. -Len

I apply it by adding a mix of Vallejo Airbrush Thinner and Slo-Dri. I then apply using VERY thin coats at low air pressure, about 15psi. The first couple of coats should barely cover, build it up slow. I don't have any issues of it drying in tip. I find that acrylics dry faster in tip at higher pressure.

Thanks for your input guys ! I've ordered some ak grey primer and see how it goes. As vallejo primer is a bit thick I thought that running higher pressure would do the trick; 15 psi seems a bit low ?

I always add one or two drops of retarder medium to Vallejo acrylics when I spray at anything under 25 psi. I haven't had any problems with needle drying since I started doing that.

I had no luck either with Vallejo primer, got a grainy finish. However I am more than happy with AK, directly from the bottle. Yes, after some time it clogs the nozzle but clean it and the needle with some water and works again.

As mentioned, I thin it with a mix of Vallejo AB Thinner and Medea Slo-Dri. I usually don't measure my mix, but I would say about 25% thinner to primer. I get a consistency of thinned paint. And again, very light coats.

Here is a video:

hhttps://www.youtube.com/watch?v=QtkyMSiFcOU

I mainly prime my models with Vallejo Primer too.
Their red and black works very great but the grey tends so splatter sometimes.

I always thin it 70:30 paint to thinner (only vallejo airbrush thinner) and a few drops of flow improver.
Works perfectly with my 0,4mm Evolution or 0,3mm Iwata.
And keep in mind only to "dust" the model with it first, very very light coats to build it up.

cheers Chris