Tamiya acrylics spurting water/thinners/alcohol (?) while airbrushing. Annoying and perplexing...

It has never made sense to me why compressor manufacturers place a water trap at the head of a compressor, especially a tankless one. It belongs down stream, maybe mounted to the side of the spray booth or at a work station. This way water has time to condense and be separated out by the separator. At the head end most of the water is still vapor and just passes on down the line where it then cools and condenses. In 1/1, water traps were some 20-30 ft worth of line away from the compressor, also the primary regulator, then a secondary little trap and regulator at the gun.

Now in airbrushing we don't move the volumes of air used in 1/1 but the principle still applies. A tank style compressor may cool enough at the tank to have collected most of the water in the tank which obviously needs draining. Just sayin.

krampus 57

I would get an inline water trapfor your comressor. 

I've got one on the compressor and one just before the airbrush

When I first started using an airbrush, I had a Badger compressor similar to yours, but mine didn't have the regulator.  I used enamel paint, so I generally painted outside so I wouldn't stink up the house with lacquer thinner when I was cleaning my brush.

On a hot humid day, I'd experience the same thing you are; a burst of liquid that dried along with the paint into a crust on the model.  I went to the local art store and they sold me a moisture trap that I put on the end of the hose by the airbrush.  It was a metal tube with a valve on the bottom end.  This didn't solve the problem completely.  I would have to open the valve regularly to let the water out, since I couldn't see it accumulating.

In your case, you mentioned that the moisture isn't collecting in your regulator. When you run the compressor, the top gets very warm which heats the air going to your brush. This hot air passes your regulator and the moisture is cooling and condensing in the hose, then it gets pushed up the hose to your brush.

If you want to make sure it's water, unscrew your hose at the airbrush when the water stats spritzing from the nozzle while the compressor is running. I'll bet a lot of water sprays from the hose.

In my previous post I recommended that you cool the fins on top of your compressor with a fan. You can also buy a second air hose from a home supply shop. Remove the regulator. Attach the new hose to the compressor, then attach the regulator to the other end, then attach the airbrush hose. With this setup, the moisture will cool and condense in the first airline so the regulator will catch more moisture. This also allows you to mount the regulator closer to your work space so you can keep an eye on the moisture buildup and pressure gauge.

To completely solve the problem, I bought a CO2 tank. These are a big hassle in my opinion, and they are dangerous to transport, so I don't recommend you go that way. I now have a compressor with an air tank... no issues with water in the line anymore.

Good luck!

Use the appropriate Tamiya thinner and chances are your problem will be solved. Sometimes using off the shelf stuff works and sometimes not so for that reason I stick to the paint brand’s proprietary  thinner to eliminate any surprises.

crown r n7

Do you have a spare hose?

Nope.

scottrc

Are you using the Tamiya brand thinner for this paint?  I had the same issues you are experiencing when using my own mix of off the shelf alcohol and distilled water and after inquiring about this problem on Tamiya's YouTube channel, was was told I needed to use Tamiya thinner only and to the exact ratio suggested.  When I did, the problems went away. 

Colors I had problems with were Flat Black, Hull Red, and IJN Dark Gray. 

Does a compressor with a tank completely solve the problem?

krampus 57

I would get an inline water trapfor your comressor. you can get one that mounts too your compressor but you have to plumb it in or they have small ones that splice right into the air line. you can pick they up at Homedepot or Princess Auto... Cheers From Calgary Alberta Canada

Ordered one today for 20USD (incl. shipping). Thanks for the rec. :)

ohms

 

 

Eaglecash867

Check your water trap, drain your compressor tank (if it has one), and shoot the airbrush with nothing in it again until you no longer see water splattering on the paper.  

 

 

 

Alright, I've drained as many drops as I could out of the moisture trap. I don't think my compressor has a tank to drain. See pic below. That's the model that I have.

I did notice that the air feed hose to the airbrush was a little unscrewed. Haven't checked that since I started using it a year ago. I tightened it. Will need to see tomorrow if it makes a difference.

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I have a similar compressor, and I have two water traps, and still sometimes get water splatter on high humidity days...on days that I am dead set to paint, I will actually take my compressor and put it in my chest freezer during painting sessions, as here, in Pennsylvania, the "cooler" summer nights arent any less humid than the hot summer days...

This technique has worked, but one of these times, I will actually have to pull the trigger and get a compressor with a tank.....

"2) The alcohol that I used to thin the paint wasn't mixed into it properly, and so it might be pooling at the bottom of the feed. But this doesn't explain why re-mixing or shaking the paint doesn't solve the problem. It should at least help temporarily."

Are you using the Tamiya brand thinner for this paint?  I had the same issues you are experiencing when using my own mix of off the shelf alcohol and distilled water and after inquiring about this problem on Tamiya's YouTube channel, was was told I needed to use Tamiya thinner only and to the exact ratio suggested.  When I did, the problems went away. 

Colors I had problems with were Flat Black, Hull Red, and IJN Dark Gray. 

Do you have a spare hose?

ohms

Should I turn up the pressure and blast it for 2 minutes?

I don't think so. That will produce more water and aggrivate the situation.

But.......it can be an interesting test to see how much water is actually being produced.

Eaglecash867

Its a good habit to get into to just run your airbrush without anything in it before your first painting session of the day to purge any water that may have condensed in the lines. 

How long would be enough? Should I turn up the pressure and blast it for 2 minutes?

Lol, I just checked the humidity in my area on my phone:

Chance of rain: 10%

Humidity: 94%

Who knew model building could get you to learn about the weather. I’m feeling more and more like a pro every day . 

In all seriousness, this took A YEAR to start occurring. I’m SURE I’ve airbrushed on high humidity days before, so either it is truly the few drops in the trap causing it, or (hopefully not) my compressor is starting to show its age and something is coming apart.

At least I have some ideas on how to solve the problem.

Thanks all. Please let me know of anything else you think may be of help to me.

If there is any water at all in your water trap, there is probably going to be water coming through your airbrush.  Try running your airbrush without anything in it for a little while and see if you can get it to dry out.  Also, the warmer your compressor gets as you paint, the drier the air will become that is coming through the lines.  But, that just makes it so the air in the compressor will now be capable of taking on more water vapor from the air, which will show up as water later on when it cools down.  I don't have to worry about this very often where I live because the humidity in my painting area rarely gets over about 25%, but sometimes I need to purge the lines when the humidity actually goes up on occasion.  Its a good habit to get into to just run your airbrush without anything in it before your first painting session of the day to purge any water that may have condensed in the lines.

GreySnake

Now I’ll only airbrush when the humidity is below 36% and don’t have a problem. 

I’d note what the humidity percentage is when that happens. My compressor is around the same size as what you have and if the humidity is above 40% water will start shooting out even with a water trap. From research it seems to be a common problem with smaller compressors.

Now I’ll only airbrush when the humidity is below 36% and don’t have a problem. 

Eaglecash867

Check your water trap, drain your compressor tank (if it has one), and shoot the airbrush with nothing in it again until you no longer see water splattering on the paper.  

Alright, I've drained as many drops as I could out of the moisture trap. I don't think my compressor has a tank to drain. See pic below. That's the model that I have.

I did notice that the air feed hose to the airbrush was a little unscrewed. Haven't checked that since I started using it a year ago. I tightened it. Will need to see tomorrow if it makes a difference.

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cbaltrin

Are you sure it's not water in your air supply?

Woah, I never thought of that. Could be! But the water trap only has a few drops in it, so few that if I try to empty it there isn't even enough to reach the exit.

Sounds like water in the air lines or airbrush to me.  Try just shooting your airbrush with nothing in the color cup onto a piece of printer paper or a sticky note.  I'll bet you'll see a splatter of water which spider webs out from the air pressure.  Check your water trap, drain your compressor tank (if it has one), and shoot the airbrush with nothing in it again until you no longer see water splattering on the paper.  Don't use a paper towel for this because as absorbent as those are, if a tiny bit of water comes out it might be undetectable.  A non-absorbent piece of printer paper or sticky note will allow any moisture at all to pool on its surface so you'll be able to easily see it.

Are you sure it's not water in your air supply?