Speckling or Flooding - How to get the Sweet Spot?

[GazB]

Hi all.

 

So I got a new airbrush, a relatively cheap 0.2mm one from Scalemodelshop.

 

I wanted to use it to apply the camouflage to a 1/72 tank. However, despite having somewhat cracked a thinning ratio for Real Color paint (basically top up the bottle with thinner), it seems some of their colours still aren't thin enough. When I tried to spray, it speckled like crazy, almost like Tamiya White normally does. But when I thinned further, it retained the speckling but was more prone to flooding. I tried adjusting the screw like I used to on another airbrush to apply some post shading or highlighting with Tamiya colours, but I can't seem to get the knack for it. I really wonder how people do those crazy thin lines on the German aircraft night camo. No matter which why I approach the paint, its either too thick or too thin. No apparent middle ground.

 

I still wasn't able to find the exact required thinning ratio of Real Color either, other than a suggestion of 2:1 paint to thinner. 

 

Any pointers would be appreciated. I keep looking forward to painting, but its starting to get laborious at times

 

Gaz

[Ratch]

Do you have a regulator on your compressor? If so turn it right down.

[GazB]

1 hour ago, Ratch said:

Do you have a regulator on your compressor? If so turn it right down.

Hi, Ratch.

 

I have a three mode mini compressor. I use it on the lowest setting but can't tailor it specifically I'm afraid.

 

Gaz

[dnl42]

 

1 hour ago, GazB said:

I have a three mode mini compressor. I use it on the lowest setting but can't tailor it specifically I'm afraid.

I was going to ask what pressure you use, but I guess that's moot.

 

Hm, Real Color are apparently lacquers. I don't use them, but I do use Mr Color. Are you sure you want to thin a whole bottle at a time? Did you thin it enough? I thin Mr Color as-needed to a consistency like 1% milk. Turns out I usually use very little unthinned paint unless I'm doing a base coat or other major color.

 

What happens if you just spray water or DIY store cellulose thinner? Does it atomize properly--spray as a fine mist--then?

 

Here's my airbrush paint process. First, I stir the paint well, until it's obvious the paint is homogeneous.

 

I usually put paint into a mixing cup using my Tamiya stirring stick. I use the stirring stick to transfer just the paint that sticks to it when I pull it out of the paint. I may do this 2-4 times depending on how much paint I need. If I need more paint, I'll pour directly from the bottle. Make sure you wipe the bottle threads clean before you recap your paint. I then add thinner; if you look carefully, there's more thinner than paint in the mixing cup. A good mix will then render the paint ready to airbrush.

 

I next put 3-4 drops of the paint thinner in the airbrush and spray that at full flow until all the thinner has been sprayed out. This allows me to check atomization to ensure the airbrush is working correctly as well as to ensure there's no contamination in the airbrush. I then pour the thinned paint into the cup and give it a quick full-flow spray to ensure the paint is properly atomizing.

 

Et voilà! Ready to paint!

[GazB]

Hi dnl42,

 

I always top up my Tamiya and Gunze bottles with thinner upon opening. It thins both of them nicely for airbrushing, with exception of something like white and keeps the consistency even for the whole jar.. However with the Real Color paint the process has only really worked well on one bottle as it would with Tamiya/Gunze in another bottle the results were passable, but in another, it ended up in either speckling or flooding, both of which rendered my attempts at a tight, clean camouflage pattern moot. 

 

There seems to be consistency differences. I should also note one of the same colours oddly gave a matt finish at one point and a satin on another, both sprayed over an XF-1 base.

 

When I tried thinning by applying it to the cup and mixing it, again the results were inconsistent, in large part due to the plant's tendency to stick to the pipette.

 

Gaz

Edited February 28, 2020 by Mike
Removing unnecessary photo quote

[dnl42]

@Gaz, did you try spraying straight thinner? Does that spray well?

[GazB]

4 minutes ago, dnl42 said:

@Gaz, did you try spraying straight thinner? Does that spray well?

Yep. There was a bit left following a clean up and it sprayed fine.

 

Gaz

[dnl42]

If thinner sprayed fine, what's the consistency of the thinned paint. I get the best result from Mr Color with the consistency of 1% milk or a little thinner.

In any event, try various consistencies. I would first try what you might consider over-thinning, more similar to the consistency of the thinner. If that sprays well, increase the thickness until it sprays well. This will be more work than going from thick to thin, but the point is to find out what thickness works.

 

Also, did you try the other pressures? Perhaps the low setting is too low? 

I spray that 1% consistency paint at 15 PSI (1 atm). I spray very thin coats, making sure it hits the surface slightly wet. If I were to open the paint flow too much, it would flood and pool. It's a matter of finger control to get just the right paint flow. Not so little that it hits dry, not so much that is splurts out. 

[GazB]

19 minutes ago, dnl42 said:

If thinner sprayed fine, what's the consistency of the thinned paint. I get the best result from Mr Color with the consistency of 1% milk or a little thinner.

In any event, try various consistencies. I would first try what you might consider over-thinning, more similar to the consistency of the thinner. If that sprays well, increase the thickness until it sprays well. This will be more work than going from thick to thin, but the point is to find out what thickness works.

 

Also, did you try the other pressures? Perhaps the low setting is too low? 

I spray that 1% consistency paint at 15 PSI (1 atm). I spray very thin coats, making sure it hits the surface slightly wet. If I were to open the paint flow too much, it would flood and pool. It's a matter of finger control to get just the right paint flow. Not so little that it hits dry, not so much that is splurts out. 

I only had to add two more drops for it to start getting thin enough to start pooling, and then there's the problem of the paint within the airbrush then being a different consistency prone to changing in the middle of a spray. But even when thinned, it still had a speckled overspray, even close up.

 

There was also the bizarre case of the test shots on my turntable surface seeming fine, but as soon as I raised the airbrush up to paint the model, paint refused to exit despite holding it at the same angle. It took a lot of work to get it moving

[bmwh548]

Put some of the paint (the one or the ones) giving you problems in a clear cup. A few drops will do. Add the thinner you normally use with those, stir and then move the cup around so paint gets on the walls as high as it can. Check for grittiness, check if the pigment is mixing properly. I only have a few bottles of Real Color, but one of them was faulty (Tire Black). It refuses to mix properly even with an electric stirrer, the pigment is just separating. Maybe you have the same problem. Also I had a grittiness problem with Revell enamel SM Black. I strained the paint through some special filters and it left behind some serious "gravel".

[dnl42]

@bmwh548 makes an excellent point. If that test is OK, try spraying some-other-brand bottle that you've successfully used in that or another airbrush.

[GazB]

14 hours ago, bmwh548 said:

Put some of the paint (the one or the ones) giving you problems in a clear cup. A few drops will do. Add the thinner you normally use with those, stir and then move the cup around so paint gets on the walls as high as it can. Check for grittiness, check if the pigment is mixing properly. I only have a few bottles of Real Color, but one of them was faulty (Tire Black). It refuses to mix properly even with an electric stirrer, the pigment is just separating. Maybe you have the same problem. Also I had a grittiness problem with Revell enamel SM Black. I strained the paint through some special filters and it left behind some serious "gravel".

Hmm, I'll see f I can give it a check

5 hours ago, dnl42 said:

@bmwh548 makes an excellent point. If that test is OK, try spraying some-other-brand bottle that you've successfully used in that or another airbrush.

Okie doke, will do. Thanks for the pointers, guys

 

Gaz

14 hours ago, bmwh548 said:

Put some of the paint (the one or the ones) giving you problems in a clear cup. A few drops will do. Add the thinner you normally use with those, stir and then move the cup around so paint gets on the walls as high as it can. Check for grittiness, check if the pigment is mixing properly. I only have a few bottles of Real Color, but one of them was faulty (Tire Black). It refuses to mix properly even with an electric stirrer, the pigment is just separating. Maybe you have the same problem. Also I had a grittiness problem with Revell enamel SM Black. I strained the paint through some special filters and it left behind some serious "gravel".

Hmm, I'll see f I can give it a check

5 hours ago, dnl42 said:

@bmwh548 makes an excellent point. If that test is OK, try spraying some-other-brand bottle that you've successfully used in that or another airbrush.

Okie doke, will do. Thanks for the pointers, guys

Update: I've discovered a few issues. In the new 0.2mm airbrush, the paint is either drying or collecting on the needle tip or crown cap almost immediately. The paint also seems to be thickening as its sitting in the cup. So the stuff at the top of the amount is denser than that at the bottom. Also had the problem of flushing the RC paint pipette with water instantly (and I mean instantly) solidifying it, clogging the pipette. Had to use a brush to transfer it in the end, which is a pain. Also had to put more drops of thinner in, with varied results. In the dunkelgelb colour I'm spraying, it worked fairly well. But when I put these extra drops into a brown colour, sworked well and then speckling. In the end I switched back to my 0.4mm single action airbrush and more or less managed to go over all of the colours without issue. In fact in this instance, the Tamiya NATO Black I was using was causing more problems, and oddly drying with a satin sheen O_O

 

One of the RC colours did that recently as well. Dead flat on one pieces, satin on another. Its extremely confusing to say the least the lack of consistency. I still don't get how anyone is supposed to prevent tip drying when the paint is probably thinner than it should be.

 

Gaz

Edited February 26, 2020 by GazB

[Duncan B]

0.2mm is quite a tight needle size to be spraying RC through, if you have another airbrush with a bigger needle test the paint in that too.

 

Duncan B

[ckw]

On 26/02/2020 at 19:34, GazB said:

The paint also seems to be thickening as its sitting in the cup.

Let me first say I have no experience with Real Color paint, however, the symptom you report sounds very much like a paint/thinner incompatibility issue. You don't say what thinner you use - tell us that and a RC user may be able to pinpoint the problem.

 

Cheers,

 

Colin

[bmwh548]

It's actually normal for paint to do that (even with the correct thinner) when you have a large amount. Lacquer thinners tend to evaporate quickly and if you take your time painting by the time you use up half a cup the remaining half is going to need another drop or two of thinners. I get that a lot, especially in warm/hot weather.

[Steve Noble]

You don't need to use a pipette for transferring the paint from the jar to the mixing cup. They are a pain in the backside to clean out if you use them for paint. Use a pipette for thinner only. For the paint use a wooden coffee stirer, free from McDonald's. Simply dip the wooden stirer into the paint and lift clear of the paint to allow the majority to run off. Then simply put over the mixing cup and you can count in one drop at a time to get the required amount of paint. Then add equal amount of thinner in drops with the pipette, a final mix and it's ready to use. 

Also I wouldn't thin the paints in the bottle. In my opinion a sure fire way to end the paints life prematurely. Just mix what you need, when you need it and use it up in one session. 

[GazB]

On 2/28/2020 at 1:41 PM, Duncan B said:

0.2mm is quite a tight needle size to be spraying RC through, if you have another airbrush with a bigger needle test the paint in that too.

 

Duncan B

 

On 2/28/2020 at 3:29 PM, ckw said:

Let me first say I have no experience with Real Color paint, however, the symptom you report sounds very much like a paint/thinner incompatibility issue. You don't say what thinner you use - tell us that and a RC user may be able to pinpoint the problem.

 

Cheers,

 

Colin

 

On 2/28/2020 at 4:49 PM, bmwh548 said:

It's actually normal for paint to do that (even with the correct thinner) when you have a large amount. Lacquer thinners tend to evaporate quickly and if you take your time painting by the time you use up half a cup the remaining half is going to need another drop or two of thinners. I get that a lot, especially in warm/hot weather.

 

On 2/28/2020 at 5:03 PM, Steve Noble said:

You don't need to use a pipette for transferring the paint from the jar to the mixing cup. They are a pain in the backside to clean out if you use them for paint. Use a pipette for thinner only. For the paint use a wooden coffee stirer, free from McDonald's. Simply dip the wooden stirer into the paint and lift clear of the paint to allow the majority to run off. Then simply put over the mixing cup and you can count in one drop at a time to get the required amount of paint. Then add equal amount of thinner in drops with the pipette, a final mix and it's ready to use. 

Also I wouldn't thin the paints in the bottle. In my opinion a sure fire way to end the paints life prematurely. Just mix what you need, when you need it and use it up in one session. 

Apologies for the delayed response. Didn't receive the notifications like I set it to ><

 

I have managed to crack the problem, for the most part. As an experiment I got two bottles of the same colour, then topped one up with thinner. The thinner I use for RC is the RC thinner, so its the correct one. I still use a pipette, however I now have a cup with a small amount of RC thinner in the bottom, which helps flush the pipette (water just gummed the stuff up). The paint sprays fairly well from my 0.4mm, and did start to spray okay from the 0.2mm (however the crown cap seems inherently prone to a gummy build up of not only RC but also Tamiya paint and is a pain to clean off while working). As far as I can tell, RC requires enough thinner to almost top the bottle, and then maybe a few more drops in the cup. Once the level drops, it can be topped a little again and that basically thins the bottle sufficiently for airbrushing. I've done this with Tamiya for the past few years and have had no problems. Same with Gunze Sangyo using Ultimate's Thinner. No issues, and also increases the amount of available paint in the jar. 

 

I've tried to transfer paint with a brush before, but it seems rather inefficient and takes ages to transfer enough over. Also thinning in the bottle ensures I always have the same mixture going into my cup

 

Thanks for the input Duncan, Colin, bmw and Steve

 

Gaz 

[GazB]

On 3/5/2020 at 2:50 PM, GazB said:

 

 

 

Apologies for the delayed response. Didn't receive the notifications like I set it to ><

 

I have managed to crack the problem, for the most part. As an experiment I got two bottles of the same colour, then topped one up with thinner. The thinner I use for RC is the RC thinner, so its the correct one. I still use a pipette, however I now have a cup with a small amount of RC thinner in the bottom, which helps flush the pipette (water just gummed the stuff up). The paint sprays fairly well from my 0.4mm, and did start to spray okay from the 0.2mm (however the crown cap seems inherently prone to a gummy build up of not only RC but also Tamiya paint and is a pain to clean off while working). As far as I can tell, RC requires enough thinner to almost top the bottle, and then maybe a few more drops in the cup. Once the level drops, it can be topped a little again and that basically thins the bottle sufficiently for airbrushing. I've done this with Tamiya for the past few years and have had no problems. Same with Gunze Sangyo using Ultimate's Thinner. No issues, and also increases the amount of available paint in the jar. 

 

I've tried to transfer paint with a brush before, but it seems rather inefficient and takes ages to transfer enough over. Also thinning in the bottle ensures I always have the same mixture going into my cup

 

Thanks for the input Duncan, Colin, bmw and Steve

 

Gaz 

I will note, oddly, that both Tamiya and RC paint have this occasional tendency to go from being matt to satin. I painted one model truck in the same colour, and it came out dead flat. I painted two others with the same bottle and it came out satin Oo

 

Gaz