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Fall is here, and with it came rain and cold. Airbrushing simply doesn't work in these conditions anymore. Paint simply turns into drops when it reaches the model. So how can I control these conditions (heat and humidity)?
Do these things help? https://www.ebay.com/p/Best-Quality-48-Inch-x-36-Inch-Magnetic-Office-Business-Board-Portable-Whiteboard/1637929765?iid=381869924340
If I use something like that I can safely airbrush in the house right?

I used to airbrush in the house all the time. As long as you are spraying acrylics (water based) and not enamels (thinner based) there are very little VOCs. You can just wear a simple filter dust mask to catch any particulates and try to do it in a big room - not in a tiny closet! Open the window a bit and you are fine.

You will need to create some sort of spray booth to catch the over spray. It will go everywhere!

airbrush hood, get some dryer vent pipe and have it vent out the house?

I made my own, due to my unique space requirements those ^ bought ones wouldn't have fit on my desk: Not only do they have the painting area, but also the air-space behind the filter and then the hose exits straight out the back. They take up more space than you might expect.


You can follow my progress on this here: https://www.dakkadakka.com/dakkaforum/posts/list/1440/549077.page#9134795 from design to building.

I tried to airbrush indoors and deal with the consequences, but I'm still getting drops on my model instead of a coat, although this time the drops were smaller. Don't know what else I can try, but it seems that an airbrush booth won't be of help.

 Power Elephant wrote:
I tried to airbrush indoors and deal with the consequences, but I'm still getting drops on my model instead of a coat, although this time the drops were smaller. Don't know what else I can try, but it seems that an airbrush booth won't be of help.

That sounds more like spidering. you may be thinning too much.

That's the first thing I tried . I don't thin the paint down at all.

 Power Elephant wrote:
That's the first thing I tried . I don't thin the paint down at all.

Only thing i can think of next is your compressor.

Does it have a water trap? is it full of moisture? is your compressor getting super hot?

It has a water trap. It only has a few drops in it. It's not getting hot. Maybe I really do need to just add more paint. In the summer everything was perfect right out of the bottle, but I guess during fall you just need more paint.

No clue than man.

Maybe one of the resident super painters can help more.

Guess I'll just use spray cans during winter and fall.

I am "lucky" and moved our washer-dryer out of the basement and am able to use the old dryer vent for my primer spray booth.
With winter coming on, you are more worried of it being too dry so that is a good thing.
For my table spray booth (acrylic, no solvents) I use a clear tote with a bunch of clips screwed into it for clear drop-sheet liner and a simple bathroom ceiling vent fan wired into a plug with some filters in it.
I use a full particle and solvent filter mask because I am paranoid.

For "spitting" I have a second dryer right where I attach my airbrush braided hose, sometimes the dryer right at the compressor does not work because the air is hot.
As it has had time to cool the vapor turns into water later on down the hosing.

Another source of spitting is when the nozzle your needle plugs to stop paint starts getting dry "chunks" in it.
You could have plain old normal paint dry in there and you need to clean both items well.
There is some tiny nozzle "file" you can use to try to clean that area.

You could try running some paint though a screen (go to an actual home paint store and they have those paper screens), worst source are those screw caps or flip caps that have dried bits that fall in the paint.

I had some issues as well using a too thick airbrush paint (Auto Air Colors I think it was) and trying to force it through a 0.2mm needle, that was when I was starting out and I thought I was losing my mind. They say I am much better now....

This is some "hard earned" knowledge for me, so I hope it helps.

Do you have a picture of what you're experiencing?

Here is a pic

I asked around on some airbrushing forum, they said that it could only be that I need to wash it before painting it. And it's true that I didn't wash it.

When you say "drops on the model" do you mean the paint is too watery and pooling?

Does the compressor have a tank? Sometimes tankless compressors need 2 water traps, one on the compressor and one nearer the airbrush.

How's the humidity this time of year? If it's just as humid inside your house as outside then you're going to have problems. If you have an air conditioner try running it for a while before you paint and see if it helps, air conditioners remove humidity from the air.

Also what sort of paint are you using? If you're using a pre-thinned paint you might be better off swapping to one that isn't.

And what are you using to thin it? Some thinners have drying retarders that make paint more likely to pool.

I know I get water spray from my airbrush because as Skink said, it's tankless with no water trap on the airbrush end of the hose. I just remember to spray it out before I start painting, though. No more than a minor annoyance.

AllSeeingSkink wrote:
When you say "drops on the model" do you mean the paint is too watery and pooling?

Does the compressor have a tank? Sometimes tankless compressors need 2 water traps, one on the compressor and one nearer the airbrush.

How's the humidity this time of year? If it's just as humid inside your house as outside then you're going to have problems. If you have an air conditioner try running it for a while before you paint and see if it helps, air conditioners remove humidity from the air.

Also what sort of paint are you using? If you're using a pre-thinned paint you might be better off swapping to one that isn't.

And what are you using to thin it? Some thinners have drying retarders that make paint more likely to pool.

The compressor does not have a tank. It's very humid this time of year. I do have an air conditioner, but it't in the kitchen/living room, and airbrushing there just isn't an option. I'm using the MiG airbrush range (acrylic). I'm not thinning it, never had it too dry.

 Power Elephant wrote:
I asked around on some airbrushing forum, they said that it could only be that I need to wash it before painting it. And it's true that I didn't wash it.

Usually there is some form of mold release no matter the process.
Washing with a detergent or reasonable degreaser is important to get good adhesion and uniform coverage with your primer.
I tend to lean toward solvent based primers to ensure any remaining oils are removed/neutralized so I do not get any strange coverage, peeling, "fish-eye" or "orange-peel".
Only then, normal airbrush should go on uniformly.
I find mixing windex or alcohol is a reasonable airbrush medium if you cannot find a suit-to-purpose liquid.

Note: too much mix and you get the dreaded spider lines.

I am having serious flashbacks right now... it hurts.

 Power Elephant wrote:
The compressor does not have a tank. It's very humid this time of year.

I'd definitely try a 2nd water trap then. I assume the one you have is mounted to the compressor itself? If so get an inline one that you mount on the hose just before the airbrush.

When the compressor compresses the air, it's also compressing the moisture in the air. But also it's heating the air as it gets compressed, hot air can hold more moisture than cold air so within the compressor the moisture just stays as a vapour, as the air passes through your hose it cools and the moisture condenses in to a liquid.

Tanked compressors are more likely to be able to get away with only 1 trap because the tank allows the air to cool so that much of the moisture condenses out before it even passes through the moisture trap, but in a tankless compressor the air is still hot as it passes through.


Automatically Appended Next Post:

 Power Elephant wrote:
I'm using the MiG airbrush range (acrylic). I'm not thinning it, never had it too dry.

In many ways I don't like prethinned paints because of the reason you mention in this thread; you need to thin different amounts depending on the weather. Some times you might want some drying retarder to slow the process, sometimes you want to use a faster drying thinner.

But that's probably not the crux of your problems (unless you have a bad pot or something).

AllSeeingSkink wrote:
When you say "drops on the model" do you mean the paint is too watery and pooling?

Does the compressor have a tank? Sometimes tankless compressors need 2 water traps, one on the compressor and one nearer the airbrush.

How's the humidity this time of year? If it's just as humid inside your house as outside then you're going to have problems. If you have an air conditioner try running it for a while before you paint and see if it helps, air conditioners remove humidity from the air.

Also what sort of paint are you using? If you're using a pre-thinned paint you might be better off swapping to one that isn't.

And what are you using to thin it? Some thinners have drying retarders that make paint more likely to pool.

When I say drops on the model I mean that when the airbrush hits the model at first I get a nice even coat but within seconds the coat dissapears and instead tiny drops of paint form.

I definitely reckon you should try the inline moisture trap. Just google "inline moisture trap" and find one that uses the same fittings as your current hose/airbrush and mount it between your hose and the airbrush.

Over here you can buy them for the equivalent of about $10USD, so it's not an expensive thing to try.

If you’re getting an even coat that immediately beads up then that’s not a humidity or temperature problem, its some residue on the model. Weather problems cause things like fuzzing, splotching, or rough textures. You need to clean your models in warm soapy water with a toothbrush to get whatever’s on there off.

 Badablack wrote:
If you’re getting an even coat that immediately beads up then that’s not a humidity or temperature problem, its some residue on the model. Weather problems cause things like fuzzing, splotching, or rough textures. You need to clean your models in warm soapy water with a toothbrush to get whatever’s on there off.

Moisture condensing out of excessively humid air can cause a similar problem. But yeah, wouldn't hurt to wash the model and see if that's the problem, I have had excessive mould release agent on some model planes I've built but it's usually pretty obvious because the parts feel quite greasy. GW models it helps to wash them first, but I've never come across one that was so bad I couldn't spray it.

This sounds like mold release on the model.
Take a sheet of paper and test with that.
If that's ok, try on some plastic sprue.

I had the same problem when I airbrushed red on a model that was already primed black.

 Stephanius wrote:
This sounds like mold release on the model.
Take a sheet of paper and test with that.
If that's ok, try on some plastic sprue.

There's no point testing on paper, paper is absorbent, if you have problems with either excess thinning or excess moisture then you might be fine spraying a porous object like paper but not be able to non-porous materials like plastic.

But yeah it's not hard to test if the problem is greasy models, just wash them, only takes a couple of minutes. I use dish soap because it's well designed for lifting grease but also doesn't leave a residue (some hand/body soaps might have moisturisers and conditioners that make it more difficult to clean miniatures).

The OP said they were spraying fine before the weather changed, so humidity combined with insufficient moisture traps is still my prime suspect.

Over here you can buy inline moisture traps from hardware stores or some hobby stores, just make sure it's mounted on the airbrush end of the hose so the air has cooled before it hits the trap.

Wait a second what PSI are you blowing at?
probably should of asked for your full accurate setup.

Between 20 and 30 PSI. That's all my compressor can muster.

 Power Elephant wrote:
Between 20 and 30 PSI. That's all my compressor can muster.

How close to the work.

usually i thin down the paint to about skim milk and airbrush at like 15 psi

about 3-5 inchs away from the work

That's around the same distance I spray from too. But, of course I try out different distances, the result doesn't change though.