Register now to gain access to all of our features. Once registered and logged in, you will be able to create topics, post replies to existing threads, give reputation to your fellow members, get your own private messenger, post status updates, manage your profile and so much more. If you already have an account, login here - otherwise create an account for free today!
New to airbrushing, Vallejo primer questions
Posted 10 February 2019 - 05:21 PM
With the recent cold and rain I thought I'd get some primer to shoot so I could keep myself and the models indoors.
I thought it would be quite easy seeing as I was doing alright trying to paint with it, but it seems like a complete different kettle of fish, it just seems to run off every where.
I washed down the model to remove any mould release agents, so I don't think that's the issue. I'm using 25ish PSI, is that too high? Seems to work well with the citadel that I'm thinning, but is that too high for specially designed airbrush paints?
Any help / tips appreciated, even if it's just to practise more!
Posted 10 February 2019 - 07:01 PM
I use around 25 psi with primer, as that gives a nice coverage and means it goes through decently unthinned. (I use stynylrez these days as I can sand it and it clogs less, but I used to use vallejo). Primer should be mostly unthinned otherwise it affects the strength of the coat later.
As a rule of thumb, if paint is spidering it's one or more of the following; pressure is too high, paint is too thin, airbrush is too close. Pressure is reasonable if you're using vallejo primer unthinned, so the remaining thing to change is pull the airbrush back from the model.
You could also try lowering the pressure some (say 20 psi) but you will get to a point where it won't spray properly as the pressure isn't high enough to 'pull' the paint off the needle at a given viscosity.
Paint sprays out in a cone from the airbrush - being further back means you get wider coverage, and the paint hitting the model has a lower pressure so will stick better. A wider coverage of course is not a problem when priming, as you want it all over anyway! If you move so far back you get 'dusting' i.e. the paint starts to dry out too much mid-air and goes on speckly, move in closer! Trigger control will also help, i.e. don't blast it all in one area but do thin coats with the trigger not fully back, moving across the model as you would with a spraycan. I prime at about 8" to 10" distance or so, estimating, and the primer goes on in much thinner coats than a spraycan (which is one of the pluses, preserves more detail!)
If your citadel paint is coming out OK at 25 PSI, then it's possibly still a bit thick for anything other than all-over base coats - my usual pressure for anything other than all-over work is more like 10-15PSI. That means I can keep the brush closer, covering a smaller area, but without spidering. To get the paint to flow out nicely from the brush at lower pressure, it usually needs to be less viscous, i.e. more diluted with thinner.
Getting the balance between pressure, paint viscosity and distance so you get paint that lays down nicely only in the area you want is one skill that you learn with airbrushing and does take a lot of practise, particularly since the paint properties varies between colours from a single maker! I still have to do test sprays on scrap paper with any given colour to make sure I've got the mix right for what I'm trying to achieve, and may tweak the PSI or dilute the paint a bit further to get there.
- LetsYouDown and HazardousWaster like this
Posted 11 February 2019 - 11:37 AM
That's some brilliant tips to take back to the table. I'll certainly try thinning the citadel paints down more. I had made my own little thinner of flow improver / water / thinners to mix 50:50 with paint so I'll try changing that up to lower the PSI and get in closer.
I'm almost losing detail at the moment where it just seems to pool in the creases, I had been using a drop or two of flow improver as well, so I'll try leaving that out and keep further away.
Glad you have also said it comes out in thinner costs, I had been getting frustrated at points where it didn't seem to be leaving a coat, then pulling right back on the trigger leaving the model then covered in runny primer!
Thanks again! I'll get back to more practising!
2 user(s) are reading this topic
0 members, 2 guests, 0 anonymous users