The challenges of spraying black paint?

[YellowHound]

I'm fairly new here and am returning to a hobby I haven't touched for many, many years.

I am having a challenge airbrushing black paint.

I started using Zero paints and lots of the parts on the car builds I have started need satin black. In Zero paints terms semi-gloss black. Every time I put this in the airbrush it doesn't spray consistently - the airbrushes splutters. I have tried thinning it further with Zero basecoat thinners (a 1:1 mix) but I get the same behaviour - maybe slightly better. I've tried varying the pressure but don't really see any improvement. Here's what a 'typical' pass looks like.

I'm keeping my airbrush scrupulously clean, and checking it closely before I paint. I don't see this issue with (so far) any other Zero paint colour.

I have also tried some other paint - I bought a couple of bottles of Vallejo Model Air Nato Black paint to try. This exhibited a similar behaviour - but only to a slight degree. It did spray better than the Zero Semi-Gloss Black.

I'd welcome any thoughts/suggestions on what I am doing wrong/what I can change for a better result. I'm achieving good results with other colours, so is black a particular challenge?

Is there an equivalent of acrylic flow improver for solvent paints?

Should I switch to an acrylic semi-gloss black? But is there one that is available in a reasonable quantity, rather than the tiny pots of most paints?

[Matt Bacon]

Most of the Zero colour matched paints are supposed to dry matt and be clear coated, so I suspect the semi gloss black must be a different formulation, which might explain why it behaves differently. As to the issue you’re having… what airbrush are you using? That pattern can only be a result of uneven paint flow or uneven air flow. For the paint, if it’s a gravity feed brush, then all you can do is make sure you mix the paint and thinner thoroughly in a jar, and only then put thinned paint into the brush. If it’s a siphon, take a close look at the little hole in the top of the jar and make sure that’s properly clear. For the air, then do you have a moisture trap, regulator and curly “rebound” hose? What compressor do you have, and what pressure are you spraying at? It could be the compressor pulsing, or pressure building up and being released in the regulator or moisture trap. 
I wouldn’t give up on the Zero satin black just yet: there are plenty of things to try. But if you do decide you need something else, the Gunze Mr Colour range spray really well…

best,

M.

[iBorg]

I'm curious as to why you ask about the hose. Can you elaborate?

3 hours ago, Matt Bacon said:

For the paint, if it’s a gravity feed brush, then all you can do is make sure you mix the paint and thinner thoroughly in a jar, and only then put thinned paint into the brush. If it’s a siphon, take a close look at the little hole in the top of the jar and make sure that’s properly clear. For the air, then do you have a moisture trap, regulator and curly “rebound” hose?

 

[Matt Bacon]

4 hours ago, iBorg said:

I'm curious as to why you ask about the hose. Can you elaborate?

 

As I understand it, the curly hose is not just about enabling you to move the airbrush away from the compressor and keeping the bench tidy. It helps the air cool and the water trap to work and smooths out any pressure pulsing from the compressor by acting as an “accumulator”. 
beat,

M.

[yh70]

2 hours ago, Matt Bacon said:

As I understand it, the curly hose is not just about enabling you to move the airbrush away from the compressor and keeping the bench tidy. It helps the air cool and the water trap to work and smooths out any pressure pulsing from the compressor by acting as an “accumulator”. 
beat,

M.

all a coil hose is good for is it provides flexibility and helps to prevent the airbrush from being pulled around unintentionally.  it does not help to cool the air or help air pressure. they a cheap way to to hook up a air brush..

 

[Matt Bacon]

12 hours ago, yh70 said:

all a coil hose is good for is it provides flexibility and helps to prevent the airbrush from being pulled around unintentionally.  it does not help to cool the air or help air pressure. they a cheap way to to hook up a air brush..

 

That’s not what the guy who sold me the set up at Scale Model World 15 years ago said… That’s why he told me specifically to set up the coil hose between the compressor and moisture trap/regulator (which is bolted to the workbench) and use a straight hose to connect the airbrush.

YMMV, obviously.
best,

M.

[peteski]

There are many different "experts" out there giving "advice", some of which might be more or less accurate. Often it's inaccurate even if the "expert" is meaning well.

There are many different compressors out there. Some with storage tanks, others without.  Also, how hot is the compressed air, and what is the recommended air temperature?  One thing that is certain is that a moisture trap is absolutely required to remove moisture from the compressed air.  But since the airbrush hose is  connected *AFTER* the trap, that air is already dry (and cool), so why would additional cooling (to the room's ambient temperature) be even needed?  Logically thinking, that curly hose cooling air thing makes no sense.

Personally, I use a Badger airbrush and I prefer using the very thin black rubbery hose from Badger. It is more  like thin tubing than a hose. The cheapest one they have.  It is very flexible and light.

[NOBLNG]

On 11/25/2024 at 12:45 AM, YellowHound said:

I'm fairly new here and am returning to a hobby I haven't touched for many, many years.

I am having a challenge airbrushing black paint.

I started using Zero paints and lots of the parts on the car builds I have started need satin black. In Zero paints terms semi-gloss black. Every time I put this in the airbrush it doesn't spray consistently - the airbrushes splutters. I have tried thinning it further with Zero basecoat thinners (a 1:1 mix) but I get the same behaviour - maybe slightly better. I've tried varying the pressure but don't really see any improvement. Here's what a 'typical' pass looks like.

I have not tried that paint so have no advice on it. Like Matt asked, what airbrush and compressor are you using? A picture of your setup might help someone pinpoint the issue?

[Dave G.]

All I can say is the Tamiya LP paints go down awesome, thinned with Mr Leveling thinner. And Stynylrez black primer/sealer as well ( Over the last 10 years or so I've probably used the Styn most as my flat black ( you can buff it with fine steel wool to get to semi gloss).. I've never used Zero paints at all, so reserve comment on that from an experiential position..

I will say that hot lacquers in general are very fussy about humidity/water. A lot of my compressed air humidity levels are limited by the fact I use an 8 gal compressor, that never runs while spraying, as it's not plugged in, thus doesn't build the heat that makes condensation in the lines an issue.. I could paint three bodies or more before thinking about cycling the motor to build air. All that aside, if all other Zero paint colors are spraying well, I kind of doubt water is causing the black to go wonky. They all should be less than optimal in some way, if water was the issue, IMO.

[yh70]

4 hours ago, Matt Bacon said:

That’s not what the guy who sold me the set up at Scale Model World 15 years ago said… That’s why he told me specifically to set up the coil hose between the compressor and moisture trap/regulator (which is bolted to the workbench) and use a straight hose to connect the airbrush.

YMMV, obviously.
best,

M.

Matt in this word and time a salesman will try to sell you ocean front property in Arizona and some will buy it. my point is dont believe everything you hear. but if it works for you that's all that counts 😐

[YellowHound]

Airbrush is a new Harder & Steenbeck Evolution 2024 CR+. 0.45mm Needle.

Compressor is a new  Bartsharp AC03 - this has an accumulator tank and moisture trap.

I'm struggling to believe an airbrush or compressor fault. I'm only having an issue with the black paint. My guess is there's a sweet spot in terms of pressure and paint consistency, that I haven't found as yet.

I'm maintaining the temperature at 18-19 degrees C (I have a temp probe at the mouth of my spray booth.

Spray pressure quoted by Zero is a 15-40 psi range. For the black I've been setting it to approx. 27.5psi - i.e. bang in the middle.

If I add thinners I always do it away from the airbrush by mixing up a quantity of thinners+paint in a fresh bottle.

[Dave G.]

6 hours ago, Matt Bacon said:

That’s not what the guy who sold me the set up at Scale Model World 15 years ago said… That’s why he told me specifically to set up the coil hose between the compressor and moisture trap/regulator (which is bolted to the workbench) and use a straight hose to connect the airbrush.

YMMV, obviously.
best,

M.

Actually your setup makes some sense. As  warm air travels from the hot compressor to the water separator, the vaporized water in it condenses. So with a coil, you can get 12' of hose in a 2-3' distance. The air will condense over the 12' traveled much better than over just two feet. You can do the same thing with 12' of regular hose though, you just have to deal with extra  routing. In our 1/1 shops I had and also worked in, we ran 30 ft of copper line before the first water separator. We still had little separators at the end of each hose that fed a spray gun. Massive water came out of the main separators in humid summer weather. I'm talking about 200 gal compressor systems. Anything close to the compressor was not very effective, least not till the whole system cooled down at night. We had auto ejection valves at the base of the compressors with small lines running outside. In that way tank water drained overnight.

Edited November 26, 2024 by Dave G.

[Matt Bacon]

1 hour ago, yh70 said:

Dont believe everything you hear. but if it works for you that's all that counts 😐

He's a guy who runs a specialist airbrush sales company, and who's helped literally hundreds of people over on Britmodeller with their airbrush issues with free advice and tech support and also sold a lot of setups to people that he's put together to meet their needs and experience, not just trying to sell the most expensive stuff. So I'm inclined to give him the befit of the doubt on this one... 😜

best,

M..

[Dave G.]

I had a spray pattern similar to that shown in the OP with some Createx pearlized blue paint. No matter how it was thinned or treated, the result was the same just thicker or thinner layers with the same spatter. I had been in contact with Createx on it, wound up with communicating with one of the owners. In the end he concluded that someplace in this paints life it had gotten frozen. He sent me new paint, a new thinner they are just releasing, and some 4030 that within our conversation he knew I used. And the new bottle of paint sprays wonderfully.  That's a company that makes you want to work with them, IMO.

So your lacquer probably did not freeze as an acrylic can, but it could be just a bad batch of paint. And if it's defective for whatever reason, it isn't ever going to spray right. You end up going through all kinds of creative ways to make something work that just plain can't. Just a thought, since I just went through a similar experience myself. And I've shot my share of Createx over the last 7-8 years, as I've used it not just for models but airbrushed T Shirt art as well.

[Matt Bacon]

2 hours ago, YellowHound said:

Airbrush is a new Harder & Steenbeck Evolution 2024 CR+. 0.45mm Needle

I don’t know if this is relevant, but there is a thread over on Britmodeller about issues with the new Evo 2024, particularly to do with assembly, the o-rings and sealing. It seems like the pressure to meet the volume and timing demands for launch may have caused some quality issues in assembly. I’m not saying that’s it, just that being a “new” airbrush doesn’t necessarily mean it’s pristine and perfect.

Have you got any auto lacquer thinner (from Halfords for example)? It might be worth experimenting with using that with the black… as I say, I think the chemistry of his gloss and semigloss paints might be different from the majority of the basecoat range (which are essentially Lechler car paints in smaller jars).

best,

M.

 

[YellowHound]

11 hours ago, Matt Bacon said:

I don’t know if this is relevant, but there is a thread over on Britmodeller about issues with the new Evo 2024, particularly to do with assembly, the o-rings and sealing. It seems like the pressure to meet the volume and timing demands for launch may have caused some quality issues in assembly. I’m not saying that’s it, just that being a “new” airbrush doesn’t necessarily mean it’s pristine and perfect.

Have you got any auto lacquer thinner (from Halfords for example)? It might be worth experimenting with using that with the black… as I say, I think the chemistry of his gloss and semigloss paints might be different from the majority of the basecoat range (which are essentially Lechler car paints in smaller jars).

best,

M.

 

Matt do you have a link to that thread? I've just had a quick look and can see quite a few H&S related threads.

The inconsistency I'm experiencing is very puzzling. In order to get to the bottom of it I think I need to spend some time doing some tests looking at spray performance vs pressure and thinner/paint ratio - but the permutations quickly spiral....

 If it's something simple like an airbrush issue then I would be delighted, but why black paint?

It's possible that it's my technique - I wonder if it's my coordination of air and paint control? Perhaps I get away with issues with other colours but the specific (what though?) of black paint cause an issue.

[Matt Bacon]

https://www.britmodeller.com/forums/index.php?/topic/235146568-has-anyone-ordered-a-hs-infinity-2024/#findComment-5097777
 

He’s talking about an Infinity himself, but Ultras have issues too, so I wouldn’t be surprised if Evo 2024s as well…

best,

M.