Having fully painted my model with Humbrol and Revell enamels, I returned a week later to apply an overall coat of Humbrol acrylic matt varnish (directly from the aerosol can).
To my horror, the underlying paint immediately began to craze. I was careful to thoroughly shake the can before use, and only applied the varnish in a very light misting coat.
Am I correct in thinking that this varnish can only be used over acrylic paint?
Paul
That is very strange, different media should not interact, and as far as I know it is common to paint enamel over acrylic or the opposite.Maybe the enamel paint is bad and did not cure correctly?
Hello!
The effect is something I also heard about and I was also able to replicate it in an experiment (remeber, never try new chemistry on an almost completed model!).
It seems unlogical, but you should never use Humbrol paints (enamels) and spray matt varnish together.
That said I found that otherwise that Humbrol flat clear is pretty good. So if you have to use it on top of Humbrol enamels, there is a trick you can use - at least that is what worked for me. I had a model painted with a mixture of Hataka orange and Humbrol, with some oil weathering on top of that and it didn’t want to go flat. I first applied Gunze Top Coat flat n my model, but it was still glossy after that. But that Top Coat apparently worked well as a barrier, because when I then applied Humbrol flat clear spray I got nice flat surface without the Humbrol enamels crazing. So maybe that’s the way to go - apply some barrier coat between Humbrol enamels and the flat clear.
Hope it helps - good luck with your modelling projects and have a nice day
Paweł
Windsor & Newton Galleria from your art/homeware shop, in Mat, Satin or Gloss are least problematical for me!
I only use (17 different brands of) Acrylics, Tamiya & AK the top two.
Humbrol mat, pot or can, is notoriously problematical, at least for me.
I had the exact problem . I usually use the Humbrol Matt varnish through my airbrush and never had any problems with it, it was my favorite. Last year I could not find it and bought the aerosol can instead and used it on my Dragon DAK Panzer IV E. I painted on a coat of AK Real Colors black base coat and then the dessert color but when I went to use the Humbrol Matt coat it ran all over. Luckily it was a small area and I just left it alone . I did not use it on the rest of the model. Weird
Interesting that others have encountered a similar problem.
Normally, I use Winsor & Newton’s Galeria acrylic varnish,
which seems to work really well. However, on this occasion
I tried the Humbrol spray varnish (as an experiment), and I
certainly will not risk that again!
Paul
I just wonder Paul if Humbrol’s enamel varnish might be the way ahead?
I would like to know which solvents are in that Humbrol matt varnish spray can.
I know - what the hell is in that can if it melts Humbrol enamels?
Yes, most confusing. As I said earlier, I will stick with the Winsor & Newton product … never a problem there.
Paul
Dunno. There’s nothing on the can about the ingredients.
But it’s made in Sandwich, Kent, England. There’s a couple of warnings on the back but that’s it. Solvent abuse is funny one……
Sorry Paul, I did not read your initial post carefully enough. I should have seen that you used the acrylic version; but I used the enamel one. But still we had the same problem. Weird
Which seems to support the idea they are not the problem, but rather the original color.
or the solvents or propellants used in the cans
I had a really weird effect with the Humbrol matt clear spray when it came to finishing up a Macchi 200 a couple of years ago. I usually only use Tamiya, but at the time my LHS had no Tamiya matt in, so tried the Humbrol.
Used Tamiya gloss, decals and then the Humbrol over to finish. Seemed to go down ok, but it dried with chalky white blotches. And that was after shaking for a good long time and warming the can. Don’t know if was a reaction with the Tamiya clear. Tried rubbing it off, but no effect. About a week or two later they got some Tamiya matt in and I sprayed it over the Humbrol and the patches disappeared! Very odd, but the project was saved.
I won’t touch Humbrol clear sprays after that.
Oh, Humbrol 49 turning white when drying is a common theme, this happened many times even before the spray version appeared on the market
I’ve had the recent stuff in the bottle do the same thing. Funnily never had a problem with the old enamel tin varnish.
Curiosity question, when the craze or white appears, has anyone applied a little touch of Tamiya X20A thinner to a small craze or white spot to see what happens?
