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AFV Painting & Weathering
Answers to questions about the right paint scheme or tips for the right effect.
Acrylic Clear Flat Woes
tatbaqui
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Posted: Sunday, December 02, 2012 - 02:53 PM UTC

Quoted Text

Yes. I had previously used a Future/Tamiya mixture that worked well, but not totally flat, and have been trying to at least get back to that....



Hi Bill,

I've use this same combo, and have no issues. For a really dead flat finish, the mix is almost all Tamiya flat -- the Future is almost just used to dilute it. Yes there will be those whitish stuff that will come up -- and my solution to that is to just keep on stirring the mix to keep it out. This is why I don't airbrush during its application. I have fairly good brush (exclusive for such work) and do it by hand. Doing it by hand lets me eyeball the mixing pallete if the whitish stuff come out. Best of all, no issues with brush marks.

Hope this adds to your options.

Cheers,

Tat
Joel_W
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Posted: Monday, December 03, 2012 - 03:50 AM UTC

Quoted Text


Quoted Text

Yes. I had previously used a Future/Tamiya mixture that worked well, but not totally flat, and have been trying to at least get back to that....



Hi Bill,

I've use this same combo, and have no issues. For a really dead flat finish, the mix is almost all Tamiya flat -- the Future is almost just used to dilute it. Yes there will be those whitish stuff that will come up -- and my solution to that is to just keep on stirring the mix to keep it out. This is why I don't airbrush during its application. I have fairly good brush (exclusive for such work) and do it by hand. Doing it by hand lets me eyeball the mixing pallete if the whitish stuff come out. Best of all, no issues with brush marks.

Hope this adds to your options.

Cheers,

Tat



Hand brushing eliminates any humidity (water vapor) from getting mixed into your flat base/future. The issue is that it happens when using a airbrush and compressor.

With so many better options today for airbrushing a flat finish, the use of Tamiya Flat just doesn't make sense. Even Tamiya has just came out with a acrylic flat.

Joel
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Posted: Monday, December 03, 2012 - 02:56 PM UTC

Quoted Text

Bill,a few more questions
1.Have you tried spraying color on something?If so does the color act the same way,as far as being rough,although maybe not frosting?
2.Are you sure your AB's are clean? Just askin',nothing personal
3.What is the temperature and humidity You are spraying in? Jeff T.



Hey Jeff...all good questions to ask!

1. Yes, I've been doing some other projects and alot of airbrushing while trying to tackle this problem. Just painted white and grey on an airliner over the weekend with Tamiya acrylics, and they came out like glass. Also painted the green color modulations on my 1/48 GAZ-67B last weekend and that paint also sprayed perfectly. Zero problems spraying any colors whatsoever.

2. I'm proud to say that my airbrushes are probably the cleanest things in my workroom. :-)
I tear them down and clean everything thoroughly after each spraying session, no matter.

3. Room temp is roughly 68 degrees F. Can't say there is any humidity. The air in my flat gets pretty dry this time of year...old fashioned radiator heating.
Quasimofo
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Posted: Monday, December 03, 2012 - 03:06 PM UTC
I only had about an hour to do any testing tonight, but I THINK I might be on to something. Just for kicks, I tried turning the air pressure on the compressor WAAYYYYY down...like just above the point where air stopped flowing. The needle on the pressure gauge was just above zero. At that point, the frosting seems to almost totally disappear. I ended up with more of a semi-gloss finish using my Tamiya/Future mixture, but the white dusting was markedly improved. Tried it with thinned down Vallejo...and it dusted just like it has always been doing. When I have more time I'll try it neet...the distilled water used to thin it might be producing trapped vapor as Joel suggested.

Tonight's results lead me to think that maybe my air pressure gauge isn't all that accurate. I've been spraying with the gauge indicating 12-18psi, but maybe it was actually higher than that causing the dusting. Will want to try some other tests at the lower pressure and see what happens.

When I have more time, I'll have to follow this theory...hopefully tomorrow if that work thing doesn't get in the way again.

Quasimofo
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Posted: Monday, December 03, 2012 - 03:09 PM UTC

Quoted Text



I've use this same combo, and have no issues. For a really dead flat finish, the mix is almost all Tamiya flat -- the Future is almost just used to dilute it. Yes there will be those whitish stuff that will come up -- and my solution to that is to just keep on stirring the mix to keep it out. This is why I don't airbrush during its application. I have fairly good brush (exclusive for such work) and do it by hand. Doing it by hand lets me eyeball the mixing pallete if the whitish stuff come out. Best of all, no issues with brush marks.

Hope this adds to your options.

Cheers,

Tat



Thanks for the hand brushing suggestion, Tat. I would have never thought of that since I haven't hand painted anything but small parts an figures for many, many years. :-)

My only concern is that it wouldn't work too well for the aircraft I do. But I will certainly want to try it on some vehicles and figures.

How large an area do you usually work with a t time when you;re brushing your flat coat on?
Quasimofo
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Posted: Monday, December 03, 2012 - 03:12 PM UTC
One last bit for the night:

I really want to give that new Tamyia XF-86 flat clear a shot.

Does anyone know of a good domestic US source for it? The only place I can find it online is on eBay, from sellers in Hong Kong and Taiwan. I don't mind ordering it that way, but I would like to have it "yesterday" and not wait for it to be delivered via carrier pigeon.
tatbaqui
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Posted: Monday, December 03, 2012 - 08:00 PM UTC

Quoted Text


Quoted Text



I've use this same combo, and have no issues. For a really dead flat finish, the mix is almost all Tamiya flat -- the Future is almost just used to dilute it. Yes there will be those whitish stuff that will come up -- and my solution to that is to just keep on stirring the mix to keep it out. This is why I don't airbrush during its application. I have fairly good brush (exclusive for such work) and do it by hand. Doing it by hand lets me eyeball the mixing pallete if the whitish stuff come out. Best of all, no issues with brush marks.

Hope this adds to your options.

Cheers,

Tat



Thanks for the hand brushing suggestion, Tat. I would have never thought of that since I haven't hand painted anything but small parts an figures for many, many years. :-)

My only concern is that it wouldn't work too well for the aircraft I do. But I will certainly want to try it on some vehicles and figures.

How large an area do you usually work with a t time when you;re brushing your flat coat on?



Hi Bill,

Ah yes, can't say much on aircraft, as I mainly do 1/35 armor. Re: area, on the average I'd say around 2 x 6 cm. I try to brush it in one continous stroke. What I noticed with Future is that it applies evenly, and it doesn't seem to buildup. At times I get small bubbles towards the edges of the surface, though a quick flick with the brush fixes it.

Cheers,

Tat
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Posted: Wednesday, December 05, 2012 - 02:06 PM UTC
After another couple of nights spent working on this, I've made absolutely no progress. It makes no difference what I do, I'm still getting frosting each and every time. I'm beyond frustration. I even think I've invented a few new curse words in the process.

The suggestions of moisture in the air all make sense, but my flat is extremely dry. Just for kicks I took apart my moisture trap and wiped it out, hoping to get rid of any residual moisture that might be in it. It made no difference whatsoever.

I also picked up a bottle of Micro Flat last night, and as Joel suggested, thinned it with 70% IPA. That frosted just as bad as the Vallejo. I've also read that Micro Flat tends to yellow, so was a little hesitant to use it but at this point it was worth a shot.

Speaking of the Vallejo Matte, I'm wondering if I have a different version of it than everyone else who has claimed success with it. Mine is a black label bottle that just says "Matt Varnish". Product number is 70.520. It is not labeled "Model Color" like eBay auction I bought it from had it described as. No idea if that makes a difference but wanted to put that out there in case it does.

I also ordered of the the Tamiya XF-86 Flat Clear on eBay. It's coming from Hong Kong, since there seem to be no domestic US sources I could find. So who knows how long it will take to get here. Hopefully that will work. If not, I'll just have to switch over to basket weaving. There is no reason I can fathom why this is such an epic fail for me.

Tat, I think I'll give your suggestion of brush painting a try on the vehicle I have almost finished. It's been stalled for two weeks because of this clear flat fiasco and really want to finish it off...but I have to get it clear and flat first.
tatbaqui
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Posted: Wednesday, December 05, 2012 - 02:40 PM UTC
Have a go at it, and see if it fits to your liking. Don't throw in the towel yet -- you'll get around it soon enough. Cheers and good luck Bill! Tat
Joel_W
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Posted: Thursday, December 06, 2012 - 02:55 AM UTC
The Micro Flat frosted when thinned with Iso through an air gun? That's an all time 1st as far as I can recall. Just re-read the directions and it specifically says to thin with either water or alcohol, which must be Iso. I thin it 50/50 and shoot at 18-20 psi.

Since you didn't use Tamiya flat base nor Future, and applied with an air brush, the issue now points to your air brush set up, and if there is a humidity issue (which you say there isn't one).

If you can get a bottle of Testors Dullcoat, thin it 50/50 with plain lacquer thinner. I use that 95% of the time, and never had a single issue. Then again, I never had any issues with Micro flat other then it's price compared to the cost of
Dullcoat.

If you still get that frosting, then it's your air gun/compressor as everything else has been eliminated.

Joel
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Posted: Thursday, December 06, 2012 - 06:37 AM UTC
I'm inclined to agree with you on the airbrush being the problem, Joel. It doesn't make any sense that I'm getting the same results with trying so many variations of product, pressure and mixing ratios.

Two more things I am going to try tonight:
1: Take apart the moisture trap again but let it air out over night, hopefully to let any moisture that might be trapped inside the innards evaporate. There is a part in the neck I can't get to, so maybe there is some vapor stuck in it…airing it out might help.

2: The moisture trap is connected directly to the compressor…that's how it was when I bought it. I think I have an extra air hose, so I'm going to run that from the compressor to the trap, then the trap to the brush.

I'm thinking the air coming from the compressor is being warmed up and might be cooling down AFTER it passes through the moisture trap leading to condensation in the line, and then causing the frosting. With the trap mid-way between compressor and airbrush, maybe the air will cool down enough by the time it hits the moisture trap that no vapor will get past it.

But I've had no evidence of any moisture in my air line spraying regular paints, so it's just a theory. But at least if neither of these works, at least I can say I tried them.
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Posted: Thursday, December 06, 2012 - 10:06 AM UTC
Bill,Talking about moisture,does your compressor have an air storage tank?If so,you might want to check and see if it has a tank drain.You will be amazed how much water builds up in the tank,and if not drained often,can bring on big problems.
I agree with Joel about the problem being equipment related.If this is happening with every clear combo you have tried,and that you have had good luck with in the past,then something has changed with your spray set-up.Jeff T.
P.S.Have you made sure that the paint cup cover vent holes in both guns are clear and open?
Joel_W
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Posted: Friday, December 07, 2012 - 02:26 AM UTC
I was also thinking about what Jeff suggested about your compressor. My unit has a large storage tank so that the compressor pump doesn't have to continuously run. It has a drain valve on the bottom, which I try to remember to open and drain every few months. You would be amazed at how much rusty water comes out of it. Another issue is the size of your tank if your compressor has one.

As far as your water trap goes, if you don't see water in it, or on the sides, it's clear enough. I wouldn't expect any build up in your hose unless it's very old and needs to be replaced.

Still, the issue is that it only happens with flat clear finishes and not with paint or gloss.

At this point I would go the Glosscoat/Dullcoat/lacquer thinner route and see what happens. Since there is no water used, you shouldn't have any problems.

Joel
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Posted: Friday, December 07, 2012 - 04:11 AM UTC
Thanks, Joel and Jeff…

You both were right on the money about draining the compressor tank. I never thought of needing to drain it, nor was even aware my tank had a screw plug on the bottom. Well, I opened it up last night, and man, oh man!!!! In the interest of good taste I can only describe what came out of it as resembling something found in a baby's diaper.

I've had this compressor since April, have used it a lot and this was the first time that drain had been opened…there was A LOT of brown crud that poured out. I was stunned. I turned the compressor on for a few minutes to let it run to force the rest of it out, and think I got most if not all of it out. I will certainly be aware of this in the future. I've also been lazy about bleeding off the air after my spraying sessions, so I have to start doing that again every time.

There was a little water pooled in the trap (it had never been opened since I bought it), the hose is brand new (as of April). I did some testing again last night after cleaning out the the tank and drying out all the parts of the trap I could get to. Still got frosting in all cases. During my test spraying, the moisture trap started to fog up a little bit, telling me there seems to be more moisture in the air than I had counted on. That might be the issue right there. I tell ya, this place is so bone dry though that I'm amazed there is any vapor in the trap. My work room does not have the radiators like the other rooms…heat flows in from the adjacent room. Maybe that is enough for the extra moisture to accumulate…who knows.

At this point I may begrudgingly have to go the Dullcote route. I still intent to use acrylic paints and Future as a gloss coat. I've read that Dullcote lightly misted over a fully cured Future finish presents no problems if it does't pool up.

Is this correct? Does anyone have any experience with that combo?
Joel_W
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Posted: Friday, December 07, 2012 - 04:57 AM UTC
Bill, the slight misting in the moisture trap is what you want, so it's doing it's job.

I use Tamiya and Model Master acrylic paints, then gloss with Pledge/Future shooting it straight from my air brush at 20 psi. One mist coat, then a light coat, then a few heavy coats. It's never smooth as done with a brush, but that's the nature of the product, as it was made for floors applied with a mop. I then apply the decals. 24 hours later I apply a few heavy coats of Pledge to seal the decals and it also makes the flash just vanish. Then over all oil washes. Then a few coats of Dullcoat, followed by more localized washes and pin washes. Another coat of Dullcoat. Then dry brushing and any detail painting. Then another coat of Dullcoat.

I've never had any issues other then my wife about the smell. I built a paint booth that helps. There is no reason to actually have the Dullcoat directly come in contact with the Future product you're using.

I'm still wondering about your clear issues. Are you sure that your color coats don't have any of that white foaming or a change in color? Have you matched the air brushed color to a piece of card stock with the color hand brushed on?

Joel
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Posted: Friday, December 07, 2012 - 05:37 AM UTC
Hey Joel-

My colors are not color shifting, but that's a good thing to ask about. I've been using a variety of color ranges the past few weeks and have had no foaming or frosting in the colors. I sprayed a lot of semi-gloss black the other night and would have noticed a color shift in that off the bat...nada.

Your workflow sounds very similar to mine, with the exception of the aircraft I do...no overall oil washes on most of them, just pin washes along panel lines and such, hence my wondering about Future/Dullcote interaction.
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Posted: Friday, December 07, 2012 - 06:13 AM UTC
Bill, I've built a few aircraft models the last few years, using
future hand brushed on. My panel washes are done as a general wash, then I use a damp cotton rag, and Q tips to remove the unwanted wash. There is a small residue left on the surfaces that really turns the pristine looking paint into a more natural weathered color. I Dullcoat right over that. I would test 1st just to be on the safe side.
If you had any water build up in your air brush it would also show up in you color coats.

Joel
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Posted: Friday, December 07, 2012 - 06:34 AM UTC
Thanks for the insight, Joel. That's the same process I use for my aircraft, but I airbrush the Future in thin coats then let it cure for at least 48 hrs (just to be on the safe side). I like how the wash gives that natural weathering as you described.

I don't believe there is any water build up in my air line the more I think about it. Last weekend I used my Iwata to freehand graffiti on a 1/35 Berlin Wall section. As fine detail work as that was, I certainly would have noticed any water build up. It's just the acrylic clear coats that I'm having issues with.

So, it seems that I'll have to just deal with the Dullcote fumes. The upshot is, at least I'll get the dead flat finished I want without all the hassle. Will definitely test first though. Having too much of a sheen on military vehicles is what I really want to avoid. And not having them frosty white, either. :-)

Thanks again!
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Posted: Friday, December 07, 2012 - 06:37 AM UTC
Bill,
I feel your pain. Polly-S was my favorite finish as well and I have just used the last of my 'stash'. I tried Testors Acryl - frosting; MicroFlat - was not flat and frosted; tried flatbase and Future - no luck. I really wish that Testors would resurrect the Polly-S brand - I loved those paints for airbrushing, brushwork, everything! (sigh)You can still get most of the Polly-S railroad colors, but their clearcoats are now Testors Acryl. Not good.

Stephen (Minas-Ithil)
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Posted: Friday, December 07, 2012 - 06:44 AM UTC
So where are you??
You think it's a stupid question but room temperature play an important role on the final aspect of the paint as well as the relative humidity.
It seems that your problem just pop up at this season.
I am shooting Vallejo paint and I am working in my basement. During winter time I am always warming up the paint before application.

So tell me
Quasimofo
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Posted: Monday, December 10, 2012 - 04:06 AM UTC
Stopped by my LHS Friday night to grab some Dullcote to experiment with….and they were out. They had two full rows of Glosscote bottles, but not a single Dullcote. DOH! Sort of reminded me of the Monty Python skit with the cheese shop that didn't have cheddar. Had them order me a couple of bottles that will hopefully be in by mid-week.

Talked to a friend this weekend who has been switching over to acrylics and has had the same issues with clear flats. He resorted to Dullcote in light mists over acrylics and has had no problems.

@Seb:
I live 3 hours north of New York City, temps are around 1-2 degree Celsius lately. My work room has a window that I use with a fan to vent out paint fumes. The rest of my flat is always very dry with no humidity with the heat going, but I think because of this window maybe the winter humidity this time of year is too high to use flat clear acrylics without frosting.

@Stephen:
Makes me a feel a little better knowing I'm not the only one going though this trouble.
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Posted: Monday, December 10, 2012 - 04:16 AM UTC
so what is the room temperature when shooting ??
Joel_W
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Posted: Monday, December 10, 2012 - 04:17 AM UTC
A bottle of Dullcoat will last a long time. Just remember to have a reserve bottle and you'll never have this issue again.

As for applying it, I just do a mist coat followed in a few min by a few Heavy coats. Dries almost as fast as you apply it, at least to the eye.

Joel
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Posted: Monday, December 10, 2012 - 05:27 AM UTC

Quoted Text

so what is the room temperature when shooting ??



Around 18-20 Celsius
Joel_W
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Posted: Monday, December 10, 2012 - 06:00 AM UTC

Quoted Text


Quoted Text

so what is the room temperature when shooting ??



Around 18-20 Celsius



A little chilly for this old bones, but it's fine for air brushing. Since you'r upstate NY, this time of year, there is literally no chance you have a humidity problem.

Just go with the Dullcoat and your issues will be a thing of th past. BTW, I use Glosscoat for those times when I want a high gloss, smooth as glass finish. Future through an air gun doesn't produce a really glassy finish, even though it self levels to some degree.

Joel