Thinning Vallejo Primers

[awilden]

Does anyone else out there that uses the Vallejo Polyurethane Primers (I guess also any equivalent airbrush based non spray-canned primers), find they need to thin it? or has always thinned it as a matter of course?

 

I had read that it was usable right out of the bottle, and for the quick single model, few drops worth of paint in the cup paint jobs its fine like that, but I've been getting the air brush all clogged up after several minutes of a (relatively) long priming session of multiple models, I would guess it would make sense to thin it to the 'milk' consistency, and if necessary just wait and do another coat afterwards?

 

There isn't any real problem with thinning surface primers is there? I would assume that if you want it nice and hard/effective just multiple thin coats would be just as good? (adding thinner shouldn't do anything to the primer where it loses the properties that make it a good primer?)

[powwow]

Having used the white, grey and black surface primers, there is definitely a difference in terms of how thin the paint is straight out of the bottle.

 

I assume you're using black (because the black for me clogs the airbrush quickly). This is experienced fairly commonly and there are a few work arounds. You can add airbrush thinner (I use the vallejo one to be consistent), you can set the PSI of the compressor up to be higher (mine sits at around 50-60 psi when I do priming), and you might need to assess your trigger action with the airbrush. Prolonged activating the trigger for the airbrush before pulling back to release the paint will dry up the paint that is already in the nozzle, leading to the build up. I had to relearn my trigger action because I was guilty of this; now I am very mindful of pulling back the split second after pushing down on the trigger. 

 

All of this helped my airbrush stay less clogged but the black primer is still a notorious clogger for me so at the moment I tend to clean a couple of times during priming sessions, but in the future I might look at using the grey primer as it doesn't seem to clog nearly as much. I can always darken the paint scheme later with inks/washes/oils anyway.

 

Hope this was helpful.

[awilden]

Having used the white, grey and black surface primers, there is definitely a difference in terms of how thin the paint is straight out of the bottle.

 

I assume you're using black (because the black for me clogs the airbrush quickly). This is experienced fairly commonly and there are a few work arounds. You can add airbrush thinner (I use the vallejo one to be consistent), you can set the PSI of the compressor up to be higher (mine sits at around 50-60 psi when I do priming), and you might need to assess your trigger action with the airbrush. Prolonged activating the trigger for the airbrush before pulling back to release the paint will dry up the paint that is already in the nozzle, leading to the build up. I had to relearn my trigger action because I was guilty of this; now I am very mindful of pulling back the split second after pushing down on the trigger. 

 

All of this helped my airbrush stay less clogged but the black primer is still a notorious clogger for me so at the moment I tend to clean a couple of times during priming sessions, but in the future I might look at using the grey primer as it doesn't seem to clog nearly as much. I can always darken the paint scheme later with inks/washes/oils anyway.

 

Hope this was helpful.

Awesome thanks for the info, i was actually using the German Brown coloured primer, but i think i was doing what you mentioned about trigger action, i had been pressing down the trigger for extended periods before releasing the paint, i had thought that was the best way to do it to slowly release the paint to prevent spattering, but it makes sense that it would cause the paint to dry up quicker in the nozzle, i guess sill have to try doing it how you suggested. Also i have the PSI set to just 30 on the compressor, I'm using an Iwata Neo CN airbrush, i had assumed that 30 was the highest that was recommended for any airbrush? (what PSI do you set yours in general? like you said 50-60 for priming, what about normal painting? and was that using vallejo paints as well?).

[powwow]

 

Awesome thanks for the info, i was actually using the German Brown coloured primer, but i think i was doing what you mentioned about trigger action, i had been pressing down the trigger for extended periods before releasing the paint, i had thought that was the best way to do it to slowly release the paint to prevent spattering, but it makes sense that it would cause the paint to dry up quicker in the nozzle, i guess sill have to try doing it how you suggested. Also i have the PSI set to just 30 on the compressor, I'm using an Iwata Neo CN airbrush, i had assumed that 30 was the highest that was recommended for any airbrush? (what PSI do you set yours in general? like you said 50-60 for priming, what about normal painting? and was that using vallejo paints as well?).

 

 

For priming I run my compressor at 50-60, and for normal/detail work I sit at around 20 depending on the nozzle I'm using. That's using the normal vallejo paints but if for example I wanted to use a GW shade to tint a base colour, I'd put the PSI down a fair bit to stop the splattering. I'm no compressor expert though, I generally do the following: priming=high psi, basecoats=medium psi 30, detail work=15psi

 

Also, before I ever put airbrush to model, I spray against the back of my hand (I wear disposable food handling gloves for this purpose), to check the spray pattern and consistency. It will tell me if it is thinned enough.

 

If you have some spare models you don't mind practicing on, I'd try different levels of thinner to primer to see if that helps as well. I reckon Australian climate plays a significant part in the airbrush process particularly when it's humid. That's part of the reason why I moved to airbrushing from spraycans - half the time, the weather wasn't appropriate for a good spraycan job.

[Firepower]

Redgab lube has helped me quite a bit with dry tip/clogging, even when I prime with lacquers.  Thinning and adjusting PSI properly is a must, but to quote a very weird source, "when in doubt, lube."

[awilden]

 

 

Awesome thanks for the info, i was actually using the German Brown coloured primer, but i think i was doing what you mentioned about trigger action, i had been pressing down the trigger for extended periods before releasing the paint, i had thought that was the best way to do it to slowly release the paint to prevent spattering, but it makes sense that it would cause the paint to dry up quicker in the nozzle, i guess sill have to try doing it how you suggested. Also i have the PSI set to just 30 on the compressor, I'm using an Iwata Neo CN airbrush, i had assumed that 30 was the highest that was recommended for any airbrush? (what PSI do you set yours in general? like you said 50-60 for priming, what about normal painting? and was that using vallejo paints as well?).

 

 

For priming I run my compressor at 50-60, and for normal/detail work I sit at around 20 depending on the nozzle I'm using. That's using the normal vallejo paints but if for example I wanted to use a GW shade to tint a base colour, I'd put the PSI down a fair bit to stop the splattering. I'm no compressor expert though, I generally do the following: priming=high psi, basecoats=medium psi 30, detail work=15psi

 

Also, before I ever put airbrush to model, I spray against the back of my hand (I wear disposable food handling gloves for this purpose), to check the spray pattern and consistency. It will tell me if it is thinned enough.

 

If you have some spare models you don't mind practicing on, I'd try different levels of thinner to primer to see if that helps as well. I reckon Australian climate plays a significant part in the airbrush process particularly when it's humid. That's part of the reason why I moved to airbrushing from spraycans - half the time, the weather wasn't appropriate for a good spraycan job.

 

Cool thank you again for replying, have a lot of stuff to consider, i reckon i'll make up some test models like you suggested too, don't want to end up ruining any good models lol.

 

I'll try the higher PSI for the priming, and thin it down a little, and try it out on a test model just to make sure. Also i do similar to what you do, i spray onto the cutting mat before i let it spray onto a model, with my first efforts at spraying i managed to get it to spatter all over a nice clean spray job, and have been cautious ever since, do a few sprays, then a quick check spray onto the mat to make sure its all good.

 

Redgab lube has helped me quite a bit with dry tip/clogging, even when I prime with lacquers.  Thinning and adjusting PSI properly is a must, but to quote a very weird source, "when in doubt, lube."

I'm just about to order a few bottles of this from my hobby shop, from what I've read its meant to be good. Right now the brush is running without lube (i did just now put a little Vaseline just to have some form of lube, but don't want that to be a long term solution, and will clean it all off and put on the Regdab lube when it comes in), initially i had been stingy and assumed i could go without it, but yeah i reckon spend the little extra and do things properly lol.

[Ovidius Incertus]

I concur that the black and German red brown do clog more quickly than gray or white.  I thin mine all the time now unless I'm doing just a single mini or a touch-up or need an extra drop or three to finish a job.  Thinning is crucial to priming vehicles or other large projects.  I also use Vallejo airbrush thinner and a few drops of distilled H20 and Liquitex flow aid (1:10).

[Firepower]

You really wont need more than one bottle. That stuff lasts a loooooong time. If not, you're using way too much.

50-60 PSI sounds crazy. There's no need to crank up a compressor that high for anything, far as I can figure.

[awilden]

Just tried out thinned red primer at 45PSI, and no problems at all, I made sure to fully clean out the airbrush afterwards (probably don't need to, but I don't want to screw up my good airbrush, and not keen on leaving any trace of the polyurethane primer in it).

 

After had a go with the white primer, and yeah they are definitely a lot different in thickness, didn't need anywhere near as much thinner in the white (probably should have left it as direct from the bottle, but I just automatically did that after doing the red like that).

 

Also it looks like the compressor is 60PSI max, and the iwata neo CN has a working pressure between 10-60PSI and a max of 100PSI, so looks like both can be cranked up further if need be, but 45PSI seems sufficient right now for primers.

 

Thanks again for all the help for everyone that had suggestions, that's what I like about this forum there's always plenty of people here to offer help.