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Tomcat Fan

Paint Compatibility

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Hello boys and Girls!

Im haveing a big problem ( again ). I build tamiya wildcat 1/48. I have used Gunze acril colours for paint sheme, then future ( 2 layers ) decals then again future ( 1 layer ), then wash of watter colours, and then i sprayed the darn thing with Model Master Dullcote ( mixet with revell paint a mix ) and those darn acrils starts to crack under those layers of future and dullcote :crying: ... Why in the He*** is happening with that colours... any help why is this happening anh how to prevent that in the future!

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Hi Tomcat Fan :crying:

First, it's possible that the thing that is cracking up is the Future, not the paint, but in any case the problem is that the deeper layers (no matter if paint or Future) are not dry enough when you spray upper layers.

If the paint is still wet or not cured enough when you spray the varnish, then the paint will still evaporate some solvent throught the varnish but at a different rate than the varnish is doing. So, you end up with two different drying/cureing speeds in two different layers, and that's what's causing the cracks.

Give the paint some more time to dry, and if you spray more than one layer of Future, keep them fine and let enough dry time between layers (I've heard that 24 hours are enough to avoid cracking).

Hope that helps :)

Raúl

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Gunze colours where drying for more than a week / at least 7-8 days ) before first layer of future, than each day one layer of future, ( 3 days 2 layers + decals ) the forth day finishing layer of future, and after at least 5-7 days i did aply the dullcote! so i think corours where dry completely reason for cracing is somwhere else!

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Hi Tomcat Fan :thumbsup:

Then it must be the future. I've never had crackings using Gunze or Tamiya, but I've had crackings due to the Future. Now if I use future, I leave it drying 24-28 hours as a minimum between layers.

I hope you find the culprit :unsure:

Raúl

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The problem is that everything was drying more than enought time! Future at least 2 days ( i didnt have time to work on model becouse of my job ) so that thing puzzles me completly!

I have Dauntles waiting for dullcote and i dont want to ruin that model too!

I think that maybee there is a problem with a paint tinner? If that thing somehave reacts wit acril future od gunze?

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Have same problem with my current build. I found that when placing too thick a layer of Future will cause cracking in the finish. The finish looks almost like a cobblestone/marble finish.

Doclum

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The finish looks almost like a cobblestone/marble finish

Is there any way to fix this problem?

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Well i think you got too many layers of Future on. You can trying cutting back ( sanding) the layer back or completely strip the paint job by using isopropyl alcohol ( I used windex).

Unfortunately I stripped the whole paint job and started again.

Doclum

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The problem is that everything was drying more than enought time! Future at least 2 days
How long was the acrylic paint drying before you applied the Future? I usually wait a week between coats. Additionally, Dullcote has laquer in it. It's usually safe but a thick coat can screw things up.

hth

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The acrylic paint was drying more than a week each ( 2 colours paint sheme, at least 2 weeks before first coat of future! ) I was talking to one of my friends, whose brother is working as a asistent for chemical engineering in the collage in it probably the model master dullcote that is affecting the paint!...

I think i will run one test. srap peace of plastic painted with acrylic paint future and one part finished with revell mat varnish and one part with Model master mat varnis. and i will see wath will happend!

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The problem is both Gunze, Dullcoat, and Future are not compatible. Gunze is a cold paint, a flexible latex-based acrylic, not a true acrylic. Future is a true acrylic, it is like a hot paint, dries very rapidly and is not flexible. Latex and enamels both are cold paints that take time to cure, but are still flexible when cured. Lacquer (Dullcoat) and true acrylics are hot paints, they dry hard very quickly and have a finish that is hard as nails. The new MM Acryls and Polly Scale are true acrylics. Tamiya and Gunze are latex-based acrylics.

Therefore, never used a hot paint over a cold paint, you will get cracking or wrinkles from the unflexible, quick drying hot paint reacting with the flexible cold paint.

Caz

Edited by redruffensore

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So there is only way for dullcote the model, to use gunze dullcote! and there will be no cracking?

Thx on info about hot and cold paints!

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Very interesting information which I hadn't seen before. Thanks for posting it. Not that I've ever had any problem shooting future over enamels (assuming Model Master paints are true enamels) but it's interesting none the less.

Edited by David Walker

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All right, I know I've posted this at least five or six times over the years, mark this as the last.

The problem is both Gunze, Dullcoat, and Future are not compatible. Gunze is a cold paint, a flexible latex-based acrylic, not a true acrylic. Future is a true acrylic, it is like a hot paint, dries very rapidly and is not flexible. Latex and enamels both are cold paints that take time to cure, but are still flexible when cured. Lacquer (Dullcoat) and true acrylics are hot paints, they dry hard very quickly and have a finish that is hard as nails. The new MM Acryls and Polly Scale are true acrylics. Tamiya and Gunze are latex-based acrylics.

Therefore, never used a hot paint over a cold paint, you will get cracking or wrinkles from the unflexible, quick drying hot paint reacting with the fexible cold paint.

Now, Steve can pin this or you people can go on forever shooting Future over flexible paints, be they enamel or acrylic. But this is my last input on this subject.

Caz

Wow - this is great stuff. So if I understand the hot and cold scenario:

Hot never over cold!! Can cold go over hot?

Here's the sequence I'm working on for my British FGR-2 Phantom:

MM Primer

MM Enamels (Dark Green, Dark Sea Grey, Light Grey)

Future

Decals

Future

Tamiya Smoke and oils for weathering

MM Dull Coat

Now am I to understand that I shouldn't use Tamiya Smoke if I'm going to finish with MM DullCoat?

Yellowbelly :worship:

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Yes, cold paint can be shot over hot paint without fear, but not visa-versa. Even though Polly Scale's Clear Gloss is a hot paint, it is not as hot as Future and the durability of the Polly Scale Gloss is heads above Future (Ever tried to sand Future?). Even though I use the MM Acryl Flat on occasion, I still think Polly Scale Flat is better than all of them out there, regardless of solvent.

Correct, I would hesitate using Dullcoat, especially from a can. Dullcoat is lacquer based. Do yourself a faver, go to a model RR store and get a big bottle of Polly Scale Clear Flat. I recommend Model Master Acryl Diluant Thinner Acryl for thinner of all acrylic paints in airbrushing. Second to that would be Liquitex Flow Enhancer. To me, Dullcoat is way too matte and cannot be buffed either.

Caz

I learned all after many FUBARs and then talking to an automobile professional who is a custom painter for cars and motorcycles here.

Edited by redruffensore

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Applying Gunze over Aeromaster Warbird Acrylics (Pollyscale) is a no-no as well. I made that mistake with my 1:48 LTD Boomerang.

Crazing aplenty!

:thumbsup:

MikeJ

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Colin

It was a nightmare, I got most of it sorted out but it is still visible. Does not detract from the build, but I know it is there!

:thumbsup:

MikeJ

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I've also had trouble using Model Master Acryl Flat over future. Looked like the surface of the desert when I was finished.

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The cold hot paint thing is true accept for one thing. Tamiya paints are true Acryllics also. They are water based, not latex. I've never had a problem with Tamiya paints ever.

Secondly, you should never use a laquer or an enamel on top of an acryllic paint. The order is always

Laquer, enamel, acryllic.

Personally I use almost all Laquers and Acryllics (Tamiya). I use Polly scale acryllic dullcote. MM clear coats, gloss or dull, yellow over time (They aren't high quality true laquers). I don't know why anyone uses them. Try Pollyscale clears, especially for dullcoat.

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hey guys, just to provide some counterpoint here:

i've never had any problems shooting future (a "hot" paint) over my gunze acrylics. never. the biggest problem to me when shooting future is stupid hairs and dust getting on the model and then getting trapped with subsequent applications.

i've even done gunze acrylics -> future -> gunze acrylics again -> future with no problems. however, lacquer based glosscoat just makes the colours run on my gunze acrylics, that's logical. i also use gunze flatcoat on top of my future

i've done about 8 models with future as the gloss, no signs of cracking over gunze acrylics. sprayed at 15 psi or less, and sometimes thinned with windex. usually after spraying my gunze paint or future, i'd put some thinner (or windex, for future) in the brush, blow back a bit, and spray out the extra diluted solvent on the model as like a kinda "flash coat". it leaves everything real shiny.

as far as testors is concerned, the first model i made when i got back into modelling, a f-16a black knights - well.. i didn't read the instructions, sprayed a super thick gloss coat over the bird, and every bit of white turned orange.

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Interesting reading!...One solution is to use Polly Scale colours and the clear finishes for perfect finishes every time. The MM Dull Coat, being a hot lacquer should never be shot over anything but a lacquer.

The Polly Scale clear finishes are the best on the market..bar none...and FUTURE belongs on the floor.

Barney

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I HAD A LITTLE PROBLEM WITH THE MODEL MASTER FLAT OVER FUTURE. THEN I SWITCHED TO Polly Scale

FLAT AND PROBLEM SOLVED, NEVER HAD A PROBLEM AGAIN AND I SPRAY POLLY SCALE OVER FUTURE.

HTH CLIFF

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Right you are Barney, Polly Scale paints, boths the military and railroad colors, are the hardest and best opacity paints on the market. The MM Acryls are thinner and spray wonderfully, but they lack any adhesion when shot directly onto plastic! They will lift with masking. If you intend to mask a MM Acrly paint, shot the MM Acryl over a primer of Polly Scale.

Tha fact that my Tamiya Acrylics are latex-based is probably due to the fact they are over twenty years old! :>) I'm sure Mr. Tamiya has changed with the times, but the only modern Tamiya paint I have is their Flesh, which is the best on the market IMHO.

Caz

Edited by redruffensore

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Right you are Barney, Polly Scale paints, boths the military and railroad colors, are the hardest and best opacity paints on the market.

Are you talking about the water-based paints or enamel? Do place a primer under the water-based Polly Scale?

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