Vallejo Model Air - what am I doing wrong???

[BikingLampy]

Getting driven absolutely ****ing mental here.

 

I'm getting massive amounts of tip dry/clogging trying to spray pretty diluted paint (nato black at the moment) and I'm busy turning what was promising to be quite a nice Wellington into a disaster zone.

 

I'm using 4 drops of  W&N flow improver, 5 drops Vallejo thinner to 15 drops of paint. (mixed in the cup by back flowing then a quick stir with a cocktail stick)

 

I get maybe 2 or 3 secs of normal (ish) spraying before the output tails off to nothing. Or it might suddenly spurt an enormous amount. Working the needle back and forth at full blast brings dried up gunge out, then maybe another second or 2 of normal spray. I absolutely can't paint in a predictable manner. Spending more time and paint squirting into thin air to try and unclog it than pointing at the model

 

The brush is an H&S Evolution - I've tried 0.2 and 0.5mm tips - I just get bigger, messier splats with the bigger needle

 

Running the compressor at 20psi as its the lowest pressure I can actually get paint to come out at, and it gives me some headroom for blasting the clogging out. 

 

I'm washing loads of water though between cupfuls, and scraping out the nozzle, but still only get a couple of seconds spraying.

 

What am I doing wrong?

 

I've had reasonable (although never astounding, possibly down to my abilities) results with VMA in the past, and I've now got quite a range of their paints as they're cheapish and easyish for me to get hold of, but it doesn't half bug the **** out of me that a paint (and I quote from the website) "especially formulated for airbrushing" can be such a pain to use in the tool it was supposedly designed for. Surely the first thing you'd engineer out is tip drying????

 

Advice gratefully received!

 

Thanks,

 

BL

[Jon Kunac-Tabinor]

Hi I suspect it is the flow improver making the paint clog iornically, I found vallejo works well with it sown thinner and retarder, full stop. Have you tired with just the thinner- and perhaps up that a little too.
It also sounds like your nozzle has gunge in it. I have the Evo silverline - so essentially the same as you, and I'm always amazed at how much gunge can come out of the nozzle when you think its totally clean.  You "can" if you are VERY careful used the released needle to gently push crap out of the nozzle, but you need to be very very careful.  Have you any cellulose thinners or liquid "reamer" as they call it in the UAS. A good soak & spray out with that will work wonders.

Vallejo do some very good online tutorials for their paints. I used them on a 1/72nd Blenhiem for a mag article as was pleasantly surprised once I followed their advice.

You will till get a bit of tip drying- have you got the two pronged "pinch" tip cap for your brush? I use that all the time. far easier to clean the tip when painting

Best of luck

Jonners

[ckw]

I'm not a VMA user, but have had similar problems with other paints. The solution was a complete strip down and clean of the airbrush. I use an H&S Ultra. I think back blowing can force paint up the tube behind the paint flow thus constricting air supply. I use back blowing when cleaning, but I'm not sure its the best idea for mixing with H&S.

 

Cheers,

 

Colin

[Steve Noble]

I've always had absolutely no problems with the Model Air, although I know some people struggle like mad with them. All I do is use them straight from the bottle, no thinner, no flow improver, no nothing. Airbrush is usually my Tamiya HG Wide 0.5mm tip, pressure around 30-35 psi. People spray with very low pressures and I've never understood that. I rarely go below 30 psi to be honest. My theory being I need enough air to blow the paint through the tip to prevent tip dry? Works for me anyway...

[ckw]

9 minutes ago, Steve Noble said:

People spray with very low pressures and I've never understood that.

Thin paint, finer needle requires lower pressure - more control and the ability to spray finer detail, intricate camouflage schemes.

 

Cheers,

 

Colin

[Steve Noble]

22 minutes ago, ckw said:

Thin paint, finer needle requires lower pressure - more control and the ability to spray finer detail, intricate camouflage schemes.

 

Cheers,

 

Colin

Ah I see. Well I only model mostly cars and bikes so I never need to spray such fine lines/detail, so that would make sense..

[johnd]

2 hours ago, Jon Kunac-Tabinor said:

have you got the two pronged "pinch" tip cap for your brush?

This sounds interesting. Do you have a link to somewhere I could get one by any chance?

 

Thanks,

John.

[BikingLampy]

Quote

I suspect it is the flow improver making the paint clog ironically

Looks like we may have a winner.... Just tried again, diluted 1:1 and while it wasn't perfect, much improved. Also mixing smaller batches (5 drops each at a time) to stop it going off in the cup.

 

Even managed to do a bit of a postshade to try and restore some of the preshade obliterated by the random spurting earlier, diluted 4:1. That's a first (although dark grey on black is not too likely to go wrong!

 

Only problem now is that I'm very low on thinner, and not sure when the order I put in over the weekend will arrive!

[Jon Kunac-Tabinor]

18 minutes ago, johnd said:

This sounds interesting. Do you have a link to somewhere I could get one by any chance?

 

Thanks,

John.

https://www.air-craft.net/acatalog/Harder-Steenbeck-126783-0.15-0.2mm-Fineline-Air-Cap.html#SID=642

With acrylics I find i get very little if any paint build op on the needed. its design to "pinch" through your figers or a cloth so it cleans the need as you wipe away. I also find its far easier to see where the paint is going too. My Silverline 2 in 1 can with these as well as the normal ones

These guys are my new go to for GSI & Tamiya paints too. Great service and the prices are decent, plus they have stock.

Cheers

Jonners

[johnd]

Thanks, Jonners, ordered. I need all the help I can get.

 

John.

[Matthew1974]

Second all that was said here regarding spraying Model Air - thin with their proprietary thinner and flow improver (I usually go with roughly a 2:5 thinner to paint ratio, mixing in a drop or two of flow improver) and dial back the pressure which for me is about 12-15 psi.  This doesn't entirely solve tip dry during longer sessions, so I also keep a bit of Vallejo Airbrush Cleaner handy in order to dampen a brush with it and very gently clean to tip of the airbrush.

Edited April 8, 2020 by Matthew1974

[Stef N.]

I would also suggest mixing a small batch of the paint/thinner you need in a bottle rather than in your airbrush cup. That way it will be guaranteed to be fully mixed.

[Shashman]

I've had similar problems with VMA, which is the paint I started using after coming back from a 20+ year hiatus recently, and buying a new Sparmax SP-20x. It was driving me nuts and I was panicking that I'd wrecked the brand new airbrush!

[oileanach]

On 4/8/2020 at 2:17 PM, Steve Noble said:

I've always had absolutely no problems with the Model Air, although I know some people struggle like mad with them. All I do is use them straight from the bottle, no thinner, no flow improver, no nothing. Airbrush is usually my Tamiya HG Wide 0.5mm tip, pressure around 30-35 psi. People spray with very low pressures and I've never understood that. I rarely go below 30 psi to be honest. My theory being I need enough air to blow the paint through the tip to prevent tip dry? Works for me anyway...

😲 Say what? 35psi? I think that'd blow holes in my minis! 😆

 

OP: BL I use a H&S with various needle sizes.

I mix around 1:1 Vallejo thinner to paint, depending on how thick the stuff in the bottle is.

I use a paint mixer on the paint in the bottle first. I started with a butchered milk frother. That lasted for years, but now I'm using a purpose built Badger one since it died on me just as the lockdown started. 

I'm lazy, so I use the back flow mixing method too.

I strip and clean the brush between colours when I've got time and I use a drop of Iwata lube on the needle before reassembly.

I got a hold of a H&S reaming tool https://www.air-craft.net/acatalog/Nozzle-Cleaning-Tool-1.html#SID=55 which I use every few cycles and an ultrasonic cleaner which sees very occasional use.

 

I mainly shoot Vallejo paint, but tbh I'm happy slinging pretty much anything water soluble in the cup. I've got plenty of GW, MiG and Coat d' Arms lying around, various inks and even some Army Painter somewhere. I've shot fabric paints and cheapo hobby store stuff before. I'm not ashamed, I'd do it again! 😝

 

What I find:

 

I get the same gloopy mess/blocked nozzle palaver if I'm not careful about cleaning between colours. I used to strip the brush every time, but I've gotten into the habit of just shooting cleaner through. The problem is I use Medea cleaner- (it comes in bigger bottles than the opposition, which is handy, 'cause like I said, I'm lazy!). It's fine as long as I remember to rinse through with water before I chuck in some more paint. If I don't it's tears before bedtime... 😄 I don't get the problem with Vallejo's own cleaner.

 

I do get tip dry no matter what ratio I mix the paint in. Timings:

 

0.15 needle- ideal for inks, bit of a nightmare with paint. TD in under five minutes.

 

0.2 needle- great for detail work at around 15psi. Fifteen minutes or a one third full small cup. This is pretty much my set up 90% of the time.

 

0.4 needle- the only one worth shooting varnish through. About five minutes at 20-25psi with varnish. 2-3 small cups of paint at 20psi, no real time limit. Several large cups of paint at 25-30psi when I feel like spraying a t-shirt or jacket.

 

I mainly paint 28mm minis. Having said that, I've had a lot of fun with HO/ 1/76th scale AFVs and 1/72 aircraft- they're quite challenging with an airbrush! 

 

 

[Steve Noble]

1 hour ago, oileanach said:

😲 Say what? 35psi? I think that'd blow holes in my minis! 😆

 

 

 

 

Yeah, but I'm spraying larger scales. 1/12 bikes and cars, 1/20 Formula 1 and 1/24 cars. Bigger subject matter, larger areas to cover. I won't get the paint throughput painting a 1/12 car with 20psi, it's just not enough pressure to pull the paint through the airbrush, atomise it and put a wet coat down on the surface.  You're painting of 28mm minis is a different story. Finer detail, smaller subject, less pressure needed 😀

[BikingLampy]

An update on this - I seemed to be getting on OK once I'd ditched the W&N flow improver. I finished off that model and am now part way through the next one, except I've hit the same problem again. The tip dry/clogging issue seems to vary by colour - most aren't too bad and are workable, but the blacks and especially white are awful. Even heavily diluted, I maybe get 2 seconds of spraying before the stream starts to go splattery, the output tails of and the nozzle clogs. Highly frustrating.

 

I'm having zero issues with Alclad primers/varnish or with Vallejo Metal colour

 

Thorough cleaning between paint colours, I have the little reamer thingy, and I don't use the nozzle cap so I can pinch off the external build up easily, but I can see that as I paint, everytime I release the trigger, the needle pokes through the nozzle less and less

 

Quote

0.2 needle- great for detail work at around 15psi. Fifteen minutes or a one third full small cup. This is pretty much my set up 90% of the time.

This is what I think I should be aiming for, but at 15psi (by my gauge which I don't trust the accuracy of) I get poor atomisation. 15 minutes and I'd need a chisel to get the paint out the cup! If its not gone in 30secs I've mixed too much and its drying as I watch!

 

I've just ordered some of the Vallejo Flow Improver. God knows when it'll get here at the mo, but I'll see what happens then.

[Steve Noble]

It seems the problem is the paints? Personally I would try something different and see what results you have. If the results are good then its surely the paint...

[Mr T]

I have used the W&N Flow Improver in the past with their 'normal' paints, but have switched  to their own brand and it seems to work much better. The few ModelAir paints I have used have come straight from the bottle and sprayed at about 16lbs indicated (I suspect a lot less coming out the airbrush). I use a Iwata Neo with a 0.3mm needle, mainly for all over work  as I still brush paint patterns, props wheels etc. 

W&N Flow Improver works well with Xtracyrlix, Humbrol (ugh!) Citadel and Revell on my experience, which might not be the same as others. 

[lasermonkey]

I think there seems to be a misunderstanding as to what flow improvers and retarders actually do. Flow improvers are a thinning medium which breaks down the surface tension of the water contained in the paint, meaning that the paint is smoother to apply, ostensibly by brush, though if you have "beading" issues with your paint, it may help there. If you've ever squeezed some acrylic paint out of a bottle and it sits there in a ball, you'll know what I mean. It also thins down the paint without reducing opacity. Most flow improvers need diluting, but check on the bottle. Here's a good primer on the subject.

 

Retarders slow down the drying time, helping to alleviate brush strokes and nozzle clogging, basically giving you more time to work the paint. With my limited experience of Vallejo, they do tend to bead somewhat, so flow improvers may posibly help with that, but they will not slow down the drying time of the paint and therefore prevent/delay nozzle clogging.

 

 

 

 

[oileanach]

16 hours ago, Steve Noble said:

Yeah, but I'm spraying larger scales. 1/12 bikes and cars, 1/20 Formula 1 and 1/24 cars. Bigger subject matter, larger areas to cover. I won't get the paint throughput painting a 1/12 car with 20psi, it's just not enough pressure to pull the paint through the airbrush, atomise it and put a wet coat down on the surface.  You're painting of 28mm minis is a different story. Finer detail, smaller subject, less pressure needed 😀

😃 I know mate. Horses for courses and all that...

4 hours ago, BikingLampy said:

An update on this - I seemed to be getting on OK once I'd ditched the W&N flow improver. I finished off that model and am now part way through the next one, except I've hit the same problem again. The tip dry/clogging issue seems to vary by colour - most aren't too bad and are workable, but the blacks and especially white are awful. Even heavily diluted, I maybe get 2 seconds of spraying before the stream starts to go splattery, the output tails of and the nozzle clogs. Highly frustrating.

 

I'm having zero issues with Alclad primers/varnish or with Vallejo Metal colour

 

Thorough cleaning between paint colours, I have the little reamer thingy, and I don't use the nozzle cap so I can pinch off the external build up easily, but I can see that as I paint, everytime I release the trigger, the needle pokes through the nozzle less and less

 

This is what I think I should be aiming for, but at 15psi (by my gauge which I don't trust the accuracy of) I get poor atomisation. 15 minutes and I'd need a chisel to get the paint out the cup! If its not gone in 30secs I've mixed too much and its drying as I watch!

 

I've just ordered some of the Vallejo Flow Improver. God knows when it'll get here at the mo, but I'll see what happens then.

I wouldn't aim for anything other than a comfortable flow of paint and a decent amount of painting time. Up your pressure a little and see if that helps.

 

If you're investing in potions it's probably worth looking at some form of needle lubricant. I use Iwata Superlube, I hear good things about Badger's Needlejuice, too. There are probably others out there. Basically, you put a drop on the needle, spread it all over and wipe off any excess. It lubricates the needle as it moves through the brush's seals and it adds a low friction surface to the needle tip that resists tip dry. It should buy you a few more minutes before the clog? 

 

Here's what I'm talking about: 

 

[Kev The Modeller]

Be weary of Superlub, it goes on lovely but in my experience it drys and turns into a sort of slime, which stops the needle from free movement, its very odd.  

 

The Needle Juice  works a treat and you need the smallest drop, a bottle will last years.  

[EMP]

BikingLampy, 

 

I hope you don’t mind me resurrecting an old post but your woes with Vallejo Air, did you manage to get the results you were after?

 

As I think you discovered, the spitting of the paint from your airbrush is usually because the paint is too thick for the air pressure being used (assuming a/b is otherwise clean).

 

Vallejo Air (VA) gives an absolutely beautiful finish (I find it’s not the most robust paint to handling - dealing with that is entirely possible but another discussion) but the key is to build up with thin layers. The thin layers will dry off quite quickly in most environments, enabling another thin coat on top without much hanging around.

 

I use a 0.2mm needle and often thin VA by 50% or more with Vallejo thinner plus a drop or two of Vallejo Flow Improver at about 20psi for base coating. If I’m doing close up work like mottled camouflage, I will use a lower pressure and thin the paint even more, depending on which VA paint I’m using, they do vary a bit, so my advice is to find a default thinning ratio/pressure that generally works and vary it a bit to suit as needed.

 

I have a sheet of paper handy and test the paint flow before committing to model. If I’m getting spitting, I’ll add a bit more thinner and retest on the paper. Once the flow is nice and predictable at the same airbrush trigger point, I’ll commit to the model.

 

Occasionally I’ll stop and clean the tip of the a/b but the flow improver usually means I can go make a cup of tea, come back and carry on without issue, and that is with a 0.2mm needle. 
 

Hope the above may be of some use to you, current and former Vallejo Air users.

 

All the best.

 

[alt-92]

15 hours ago, EMP said:

I have a sheet of paper handy and test the paint flow before committing to model. If I’m getting spitting, I’ll add a bit more thinner and retest on the paper. Once the flow is nice and predictable at the same airbrush trigger point, I’ll commit to the model.

^^  Those bulk rolls of kitchen paper towels are handy for that.

[Ratch]

I use VMA. I never mix anything with it, use it straight from the bottle on the lowest pressure to squirt the paint through the airbrush and have never had a problem with clogging.

[Scargsy]

I've had mixed results with it but would like to try again - I moved over to shooting more lacquers due to the lack of tip drying (the thinners in the new paint dissolves dried paint).

 

For me I find VA primers actually seem to work a lot better for me (not sure if that's just placebo), I sometimes wonder if this paint itself is going lumpy/dried flakes in the bottle with fresh/full bottles always spraying better - any suggestions on filtering it (a nice fine mesh something in the top of my paint cup could possibly catch nasties).

 

Generally I found VMA worked well for me (when it worked) at around 20 psi, better through a 0.4mm than a 0.2mm nozzle. Though I'd get intermittent flow between successive triggering on the airbrush (I'm wondering if that's clogging in the nozzle?)

 

Anyhow it's too cold and humid for me to test water based here in the UK at the moment, I paint in the corner of my unheated garage and the moisture in my respirator is still there hours later if I forget to wipe it out, so the paint curing times would be nightmarish!