Switching colours mid-session?

[Wizball]

One of the reasons I find airbrushing tedious and not as fun as it could be is that I find myself cleaning the airbrush far more than actually painting. MAIN problem I have is that I find it almost impossible to quickly change colours mid-session. I own two brushes: H&S Silverline (mostly the 0.2 needle but also the 0.4) as the main brush and a Paasche H I use for non-detail work, e.g. varnishes, priming and so on. I mostly (and want to) use Vallejo/AK acrylics.

 

What I TRY to do is paint - tip out the excess paint - flush it through with medea airbrush cleaner - fill it with the new color and continue painting. I do think this should be possible.

 

What happens in reality is that after I've flushed (checking that it sprays cleaner solution) and re-filled the cup NOTHING comes out. I then have to empty the cup again, making a mess of everything, take everything apart, clean thoroughly and THEN I can spray the new colour. My best guess is that rubbery half-dried remains from the surface of the previous colour get in the nozzle and clogs it from inside. Trying to clean the tip from the outside never helps.

 

Does anybody have any guess on what's wrong with my method? Am I being unreasonable?

 

I do think I have other problems related to drying paint as well. Perhaps not thinning it enough in the first place? This manifests as it being difficult to restart painting after putting it down for ten seconds. I read the "drying tip" thread below and I recognize the issue and will try a few of the solutions. With the Paashe I usually can get restarted if I unscrew the nozzle a half turn and then back again and last time I painted a whole 1/35 tank I had to stop mid-session, disassemble and clean the Silverline and then resume painting. Yet again, wiping with a Q-tip from the outside never works.

 

After painting I think I'm just far too anal about cleaning the airbrush and keeping it spotless for next time. I usually spend about 25 minutes cleaning and hating myself the entire time. I guess I should be a bit sloppier and instead deep-clean with my ultrasound cleaner at regular intervals.

[bmwh548]

Takes me about 5 minutes to clean up the Ultra (enough for a color change) which basically has the same front end as your Silverline does. A deep clean takes about 10 minutes (which means taking the whole front apart). I think the problem might be with the airbrush cleaner? Are you sure the pigment actually dissolves in the stuff? A lot of waterbased paints turn into a thick goo in contact with certain solvents. Which is why I usually clean up with the same thinner I used for painting. Put some cleaner in a shot glass and add a drop of paint. Stir it and watch what happens. If the pigment starts to separate then the cleaner isn't suited for the job.

[Pin]

H&S Focus / Evolution, takes about 1-2 minutes to clean between colours. 

I fill full cap with either IPA, cellulose thinner or white spirit (dependng on the type of paint used), while the cap is still full I use an earbud to clean the airbrush down to the needle. Then I remove the needle and wipe it with a piece of cloth, while dirty thinner soaks just by gravirty through the nozzle. If by the time when I'm finished with the needle there is still some thinner in the airbrush I push the trigger and blow it out (remember, the needle is removed). Then I fill it with the thinner again (still no needle) and repeat the operation with another earbud as usually there is some paint left. Then I re-insert the needle and run the thinner for the third time, usually by that time the thinner comes out nearly clean.

I also do thorough cleaning regularly when I disassemble the airbrish competely and clean with brushes, recently I found that intradental brushes are perfect for that. 

 

1 hour ago, Wizball said:

flush it through with medea airbrush cleaner

What is it based on and what paints are you using? Technically speaking there is no such thing as "universal airbrush cleaner" as different paints have different bases. 

Well, cellulose thinner IS a "universal airbrush cleaner" but it may be just a bit too stinky 

 

1 hour ago, Wizball said:

I mostly (and want to) use Vallejo/AK acrylics.

For these I use just plain water and .... Sainsbury's basic vodka! No kidding, vodka is 40% ethanol, AK/Vallejo are water based acrylics. I find that pure IPA is too strong for these paints and make then clog but vodka is just right

 

[Steve Noble]

I simply mix what paint I need and use that until it's almost empty/gone. Then when I want to change colours I simply take a piece of tissue and wipe out any excess paint/residue from the airbrush cup. Add a small amount of cleaner and spray through until it's clear. Sometimes I'll quickly remove the cap and wipe the needle tip, but that's not always necessary. I never find cleaning takes longer than a minute at best and I never take the brush apart unless I have a problem where it won't actually work. You don't need to be over zealous with the cleaning. I think a lot of people who say they hate airbrushing and get clogged tips etc are using acrylic paints that tend to dry a lot inside the airbrush and tip especially. I only use lacquer paints and never have any issues with paint drying and clogging the airbrush. I don't faff about with flow retarder or any such stuff. Straight Mr Color mixed with their levelling thinner is all I use and it gives great results every time..

[Wizball]

5 hours ago, bmwh548 said:

I think the problem might be with the airbrush cleaner? Are you sure the pigment actually dissolves in the stuff? A lot of waterbased paints turn into a thick goo in contact with certain solvents. 

I haven't done any specific tests, but Medea (it's actually made by Iwata) is cleaning out the paint well enough. It doesn't dissolve the gummier bits of paint (for example the ring that the paint leaves in the cup) but the paint gets out with the help of a Q-tip/earbud just fine. But yes, the stuff might be too weak/not perfectly suitable. Should probably order Vallejos own stuff.

 

4 hours ago, Pin said:

Then I remove the needle and wipe it with a piece of cloth, while dirty thinner soaks just by gravirty through the nozzle. If by the time when I'm finished with the needle there is still some thinner in the airbrush I push the trigger and blow it out (remember, the needle is removed). Then I fill it with the thinner again (still no needle) and repeat the operation with another earbud as usually there is some paint left. Then I re-insert the needle and run the thinner for the third time, usually by that time the thinner comes out nearly clean.

 

For these I use just plain water and .... Sainsbury's basic vodka! No kidding, vodka is 40% ethanol, AK/Vallejo are water based acrylics. I find that pure IPA is too strong for these paints and make then clog but vodka is just right

 

I've always removed the needle by unscrewing the cap and nozzle and pulling the needle forward (which means basically a full disassemble, which I'm trying to avoid). After wiping it I reinsert it from the back when everything else is clean and assembled again. That way I avoid getting too much paint through the body into the trigger area, but perhaps I've been doing it wrong? 

 

Vodka seems interesting, but isn't it possible to get the same result diluting IPA down to 40%? I thought all alcohols gel-ified Vallejo but I perhaps should try the vodka out!

 

[Chrissy_J]

I've struggled so much with Vallejo's Model Air paints that at times it has put me off painting anything, ever. It spits, it dries on the tip, it blocks the AB, it's grainy when it decides to come out, I can't measure it accurately or thin it consistently - every colour has been different - and yes, I've spent a LOT of time cleaning between colours.

 

But since I moved to Tamiya acrylics, with their alcohol base, my cleaning time has been much reduced. Though I suspect it's partly because I'm being more exact with mixing and thinning ratios, using pipettes and syringes. I also now make my own airbrush cleaner which is really just distilled water with 5% household ammonia by volume, though I think it was a bit strong as it seems to have worn the chrome off the bottom of the paint cup.

 

If Vallejo's range was formulated like Tamiya I'd be a very happy bunny indeed.

[Pin]

With Vallejo - do you shake it well? I mean WELL? Good half a minute of shaking like hell? 

Higher pressure would help too