Chalky flat coat.

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Meter rat
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Chalky flat coat.

Post by Meter rat »

Today has been an unmitigated disaster, with the small scale models. Has anyone had this happen to to them? Painted the model with Tamiya paint and gloss coated for the decals. All has been allowed to dry for 24hrs. Came to spray the final flat coat, still using Tamiya products, and this happened.
AD538073-2EE2-40DD-9979-45FE922B3D15.jpeg
Flat coat has kind of turned white and chalky. At first I assumed the clear coat was contaminated, so used a second jar and the same thing happened. Paint was thinned and sprayed from a distance.
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HERMAN BIX
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Re: Chalky flat coat.

Post by HERMAN BIX »

While I have had this occurrence in a much lesser level, humidity is allegedly to blame.
That said, it’s a wonderful winter whitewash ;)
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Sub
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Re: Chalky flat coat.

Post by Sub »

Hi,

Could be it was too hot / humid a day, looks like the medium has separated from the thinners prior to hitting the model, ie dried out as thinners evaporated during spraying, you said you sprayed it from a distance ?.
There is such a thing as too hot to paint
Just out of curiosity if you sprayed it what are all the marks underneath it.
Feel your pain, nightmare, you may be able to repaint over it though.
Sub.
Meter rat
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Re: Chalky flat coat.

Post by Meter rat »

Thank you for the replies Herman Bix, and Sub. Saturday was a very warm day, for Scotland that is, and I was outside. No idea about the marks. Next time I will do a test piece before spraying on the model.
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MrChef
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Re: Chalky flat coat.

Post by MrChef »

Meter rat wrote: Mon Aug 15, 2022 6:00 pm Thank you for the replies Herman Bix, and Sub. Saturday was a very warm day, for Scotland that is, and I was outside. No idea about the marks. Next time I will do a test piece before spraying on the model.
Hey Mr. Rat, I always wondered how you remedied this? Removal of clear coat? Full repaint?
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Meter rat
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Re: Chalky flat coat.

Post by Meter rat »

MrChef wrote: Wed Apr 03, 2024 3:33 am
Meter rat wrote: Mon Aug 15, 2022 6:00 pm Thank you for the replies Herman Bix, and Sub. Saturday was a very warm day, for Scotland that is, and I was outside. No idea about the marks. Next time I will do a test piece before spraying on the model.
Hey Mr. Rat, I always wondered how you remedied this? Removal of clear coat? Full repaint?
I ended up removing it with Tamiya brush cleaner. I think I used flat base, which is for mixing with gloss paint to make it flat. There are still places where it is visible. The moral is don’t mix up X22 clear and X21 flat base. :{
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blimp
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Re: Chalky flat coat.

Post by blimp »

X21 is very similar to the matting additive , ground marble , a medium sold in artist stores . Intended to reduce gloss . (not all stock Tammy paints are available in matt)
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ColemanCollector
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Re: Chalky flat coat.

Post by ColemanCollector »

Looks like a window pane that's been hit by Jack Frost.
The final coat--my pulse rate quickens every time!
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Panzermechaniker
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Re: Chalky flat coat.

Post by Panzermechaniker »

I remember when I was painting my first tank and reading about this frosting issue with clear coats. Not sure if it is more an issue with air brush coats as I spray bomb. I just put my rattle can in warm water for a few minutes and then shake the hell out of them for a couple of minutes. Never had an issue with either Tamiya, Testor's or AK spray bomb semi gloss or flat varnishes using that method. I only apply gloss by brush under where the decals are going
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Ecam
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Re: Chalky flat coat.

Post by Ecam »

Under the decal? Is that to give them a better surface to adhere to? I'm assuming the matt/flat top coat gets rid of the sheen.
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