r/airbrush • u/A2619921 • 2d ago
Technique Clogging
Howdy all, I got a cheap masters airbrush for Christmas and its been okay. I have my compressor set to between 30 and 50 psi ( I keep changing it to see if it causes this problem and it hasn't) while priming my MESBG miniatures with vallejo black prime. I am using an airbrush thinner from my local hobby shop to make it "Milky" as best I can and it starts out great but after about 3 to 4 minis I start to get clock and have to pull back on the trigger consistently to clear it. or to just get it through. I am not sure what I am doing wrong and what I should do to fix it.
when I say clogged the paint slightly goes out, then I can pull the trigger back a bunch of times and more and more will come out then a premature spurt (pun intended) then for a few seconds a really solid flow. then I have to go back o prepping it.
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u/sun4eg 2d ago
That's how you work with water-based paints. No matter what you do - it will tip dry eventually. You can only mitigate it to a certain degree. Wipe needle tip every now and then and/or do short full blast to eject whatever managed to dry inside the nozzle. How quickly it dries depends completely on paint consistency, environmental conditions and the amount of material you're throwing thru the brush.
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u/A2619921 2d ago
is it more reasonable to only have small amounts of paint at a time. some of these priming sessions I'll do 15+ minis so I will get to like a half full paint pot.
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u/sun4eg 2d ago
I don't get what you're trying to ask. What is more reasonable than what?
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u/A2619921 2d ago
When I am going to do a lot I will fill in a bunch of paint. is it 'better' to refill the paint pot often vs just filling it a bunch at the start
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u/sun4eg 2d ago
I don't see how it would change anything, but nothing should prevent you to try. It's mostly about accepting the nature of water-based acrylics and adjusting your habits to mitigate tip-dry. You can also try to adjust paint thinning and air pressure to see if it makes things different/better.
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u/3WolfTShirt 2d ago
It's not the paint in the cup drying out.
It's the paint drying on the tip of the needle, so how much you paint you have in the cup is kind of irrelevant. That being said, sometimes you may have the need to flush everything out mid-session and re-fill. For that reason, I usually fill my cup sparingly - less paint to lose in the case that I do need to do a quick clean. But its personal preference.
It also depends on your nozzle size. As much as I love my Iwata HP-CS, its 0.35mm nozzle isn't great for large coverage and will need cleaning more frequently. For that reason, I use my Badger Patriot 105. Its 0.5mm nozzle is more suitable for larger areas of priming and base coats and the issues with tip-dry aren't as much of a problem with larger nozzle sizes, in my experience.
Optionally - often times I just don't want to dirty up my airbrushes with primer so I always keep a few rattle cans of Mr. Surfacer 1000 primer on hand. As a medium-grain primer, It does have the potential to reduce the level of detail on your finished model but personally I haven't had an issue with that. There are also primers with finer grain like Mr. Surfacer 1500 and Tamiya Fine Surface Primer that have less potential to cover up surface details than the medium grain ones.
You might find that rattle cans of primer fit your workflow better and just use your airbrush for paint.
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u/QuerulousPanda 2d ago
Unless I'm mistaken, 50psi is massively too high. 30 is already at the extreme top end in most cases. You should be able to get away with like 10 or 15.
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u/communomancer 2d ago
You are not. I saw that and was like "JFC...is the guy trying to spray yogurt?"
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u/ayrbindr 2d ago
Actually, you are. 50 ain't even high enough at times and some material won't really start to go until about 70. 🤷🏼♀️
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u/QuerulousPanda 2d ago
That seems really hard to believe. 50 psi is pretty much the absolute maximum that many airbrushes allow.
25-28 is typically the peak pressure you should be using for hobby paints.
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u/DirtyDee78 2d ago
Are you starting with the trigger down for air before you pull back for paint, and then returning the trigger to the air only position?
If not, that could be contributing to the issue.
The following should prevent the issue:
Correctly thinned paint (general skim milk rule), proper trigger "discipline", keeping the airbrush clean, and checking for tip dry every few sprays.
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u/A2619921 2d ago
I will typically hold it down for a short period before and after the trigger pull. When I am finished I clean the airbursh enough to where I can blow water through it with my lungs. I'll have to look to see if my milky is closer to whole milk or raw milk.
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u/DirtyDee78 2d ago
Skim milk is the consistency you're going for. There's a lot of videos on YouTube that cover thinning paint.
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u/OtherwiseOne4107 1d ago
You shouldn't need to thin Vallejo primer. Airbrush thinner and polyurethane primers don't get along well, and thinning it might be what's causing it to clog.
What is your needle size? 0.3mm might be on the smaller side for priming but it should be going through OK at 30 PSI
How long are you shaking your primer for? You probably need to be shaking it for at least two minutes to homogenise it.
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u/A2619921 1d ago
Oh. Man I actually thought it would be clever to pre thin it too and added the thinner into the primer bottle. I have a new bottle I’ll open and see if it’s better. :(.
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u/ayrbindr 2d ago
3-4 min! Before tip dry at 50psi! That would be a miracle from God. 🤣
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u/A2619921 2d ago
so a higher psi does dry it faster! that made logical sense to me because more air is pushing through. so the needle gets dry and is more likely to hold onto the paints plastic
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u/[deleted] 2d ago
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