Airbrush consumes a lot of color and weird trigger problem

[Nunae]

Hi there,

I've had an airbrush I received as a gift for quite some time (Revell Basic Set) and I decided to use it on actually painting miniatures instead of just basecoating some terrain or bases now and then.

 

Two problems I've had so far:

- The whole thing seems to consume a lot of color compared to brushing by hand. 

- The airbrush has a trigger for just the color, how much air is being shot out is regulated on the compressor. When I pull back the trigger, the color is supposed to come out. It does so sometimes, mostly after I freshly refilled the cup on top, but after a while it doesn't shoot color when pulling the trigger back but rather when I release it. This leads to me jiggling around with the trigger to get color out. It has always worked that way, but it's not as bad when you're just spraying a base or something, since accuracy isn't a goal there.

 

I tried thinning the paint more, but I arrived at a point where I was basically spraying tinted water that wouldn't stick to anything without solving the problem. 

Has anyone encountered that trigger problem? Is it common for an airbrush to use up way more color than it'd take to paint the same thing by hand? 

 

Ah, and where do you guys mix your paints for the airbrush? I'm having problems thinning smaller amounts of paint on my palette and transferring it to the airbrush. Is it save to mix inside the airbrush cup itself?

[Gadgetman!]

What's the air pressure on the compressor output?   

It may be way higher than it should be. 

 

I use 'flip cap sample tubes' I buy on eBay. I keep a stock of 2ml, 5ml and 10ml tubes.   

For larger mixes I've used dropper bottles.

[Cyradis]

I've been mixing paint inside the cup on the airbrush. I have a junk brush to stir, and I also back-flow to bubble it.

 

 

[ultrasquid]

A surprising amount of paint is lost to overspray. It is normal to expend more paint to achieve similar coverage to brushed-on paint, but it will generally go on more quickly and evenly with the airbrush once you learn to control it more effectively. Sometimes the nozzle of the airbrush will get fouled with dried paint and not perform correctly, so when it starts that reverse trigger behavior you're noticing, it's time to clean the nozzle and needle.

 

As for overthinning your paint, you'll need some acrylic Airbrush Medium. It's nearly as thin as water, but has as much acrylic resin as a varnish and includes additives to keep it from gumming up the airbrush. 

A lot of people mix their colors in the cup, but it's an awfully unpredictable thing to do with the remnants of the earlier color and whatnot. I've used condiment cups from a restaurant supply for that but those sample tubes Gadgetman has look ideal.

Edited September 30, 2019 by ultrasquid

[Cyradis]

I run water through the airbrush before switching colors. No worries about earlier colors.

[Corsair]

I was given this suggestion and it has worked for me. I keep a bottle of window cleaner handy and when I change out the cup for another color, I spray it into the cup and then run it through until it sprays clear, then go to the next color.

[Heisler]

12 hours ago, Corsair said:

I was given this suggestion and it has worked for me. I keep a bottle of window cleaner handy and when I change out the cup for another color, I spray it into the cup and then run it through until it sprays clear, then go to the next color.

 

Just be aware that chemicals in window cleaner, especially ones with ammonia will break down the rubber o-rings and seals in an airbrush overtime.  If you want to use something other than water to clean buy a dedicated airbrush cleaner fluid, otherwise you maybe voiding any warranties provided by the manufacturer.

[Corsair]

1 hour ago, Heisler said:

 

Just be aware that chemicals in window cleaner, especially ones with ammonia will break down the rubber o-rings and seals in an airbrush overtime.  If you want to use something other than water to clean buy a dedicated airbrush cleaner fluid, otherwise you maybe voiding any warranties provided by the manufacturer.

Thank you! I always clean the airbrush when I am done with hot, soapy water and then rinse anyway, but definitely good to know!

Edited September 30, 2019 by Corsair

[Cygnwulf]

4 hours ago, Heisler said:

 

Just be aware that chemicals in window cleaner, especially ones with ammonia will break down the rubber o-rings and seals in an airbrush overtime.  If you want to use something other than water to clean buy a dedicated airbrush cleaner fluid, otherwise you maybe voiding any warranties provided by the manufacturer.

Just going to point out that Ken Schlotfeldt of Badger Airbrush stated that the ammonia based ones will eat the plating off the brush and leave you with the bare brass layer, which would then start to corrode.  So yeah... seals can be replaced, polished surfaces inside the airbrush not so much.  He has been vague on the non-ammonia kinds but I haven't ever seen anyone pin him down and get him to say one way or the other.  I've also spent a lot of time on airbrush groups and researching stuff, seen lots of instances of problems from ammonia based cleaners, but nothing but 4th and 5th party accounts of any damage caused by non-ammonia kinds.

tl;dr : Probably best to use an actual airbrush thinner or just plain water.

[Clearman]

I spoke to Ken at ReaperCon regarding a weird trigger issue I was having with my Patriot.  We talked for about 20 minutes, and it boiled down to two recommendations:

 

1) Use less paint in each session and spray a non-alcohol, non-ammonia cleaner through the brush after each session.  The reason being is as soon as you start spaying, paint is drying (inside the post and brush, as well as the needle tip and model).  The less paint used, the shorter the time between rinses.  Adopting this practice did seem to help with the issues I was having

 

2)  If you do need to soak the brush, he recommended using Vinegar as it will not degrade the internal o-rings.  I have not had an opportunity to try this method.

[Cygnwulf]

 

going back to the original problem - I struggled with this at first too, not understanding everything that was going on. Certian paints were worse at this than others. there are two things that can cause this 'tip dry' to happen.

Sometimes this is caused by either a small bit of dried paint caught near the tip of the nozzle, or because your paint is drying too fast in the airstream.  

Either way, what happens is some of the paint passing through the nozzle around the needle, instead of being plucked off and sent flying by the airstream it instead puddles around the dried bit, and then dries and makes the dried bit larger, until so much has built up that the airstream no longer pulls a vacuum across the tip of the needle. Moving the needle forward 'squirts' a small amount of the trapped liquid paint out, which is why you get that puff of color as you work the needle.

 

Solution

 

First, you'll want to be sure you soak your nozzle in a good airbrush cleaner.  This should have solvents that break up the resins in the paint without causing damage to the metal or gaskets.  Then rinse it thoroughly. use your hobbby magnifier to carefully inspect the nozzle for any bits of color other than the bare brass. If you see any, repeat.  Also watch for shiny spots that may indicate a crack in your nozzle. 
I use some large needle 'labratory' syringes for refilling my ink cartridges for my pens, and I found that the tip of one of them (if it's a flat tip and not an angled tip) will seat smoothly around the outside of my nozzle so I can force a stream of cleaner through. (be careful not to apply pressure when doing this.)

 

Second, the best additive I've found for preventing this is a flow improver.  Personally I use the Vallejo Airbrush Flow Improver, but I know there are others.  Note that this is not the same as an airbrush thinner, and should be used in conjunction with one, not as a replacement.  When mixing MSP paints for spraying, for instance, my recipe starts somewhere around 3 drops paint, 1 drop flow improver, 1 drop airbrush reducer, and 2 drops water, and then I do a test shot on a paper towel to see if everything is moving smoothly, otherwise I adjust.  

 

Also, I don't like mixing in the cup.  The fact that I use a pronged protector making it difficult to seal a fingertip to the end is not the only reason.  Mixing in a side cup allows you to be sure everything is fully mixed without any thicker paint getting down around the needle and up against the seal or in the channel, places difficult to hit with a brush in the cup.
Lastly, for me, I make sure to use the lid on my color cup. I didn't at first because I saw all the videos of guys online leaving it open and adding/swapping colors etc, but what i've found is that, if I'm working a single color for a while, I end up with a dried ridge of paint around the top of where the paint was.  Bits of that can be knocked loose and will then definitely clog your nozzle.  Keeping the cap on reduces this.

1 minute ago, Clearman said:

I spoke to Ken at ReaperCon regarding a weird trigger issue I was having with my Patriot.  We talked for about 20 minutes, and it boiled down to two recommendations:

 

1) Use less paint in each session and spray a non-alcohol, non-ammonia cleaner through the brush after each session.  The reason being is as soon as you start spaying, paint is drying (inside the post and brush, as well as the needle tip and model).  The less paint used, the shorter the time between rinses.  Adopting this practice did seem to help with the issues I was having

 

2)  If you do need to soak the brush, he recommended using Vinegar as it will not degrade the internal o-rings.  I have not had an opportunity to try this method.

 

Have not heard the vinegar trick, but I do trust what  Ken has to say and it sort of makes sense.

[Nunae]

Ok, thank you all again for answering, I read everything and then forgot to answer again.

 

Moving the airbrush closer to the model really helped me and I was cleaning all the visible parts as I moved along, including the tip. Now I did a deep clean over the weekend (and it sure was necessary), but afterwards the airbrush blows air out of the trigger hole instead of the front. Thank god I tested the air stream before filling in paint again, but it sure is inconvinient.

 

Any ideas on where we went wrong in putting it back together? 

 

[Cygnwulf]

if air is coming out the trigger hole it sounds like the valve isn't in place correctly.  Did you remove the valve assembly during your deep clean?  

I don't have this particular model of airbrush to know if that's possible.....