Humbrol Clear Coat

it all depends on on how thick you sprayed it on. Water based paints are not impervious to solvent paints. Acetone and laquer thinner will disolve water based paints. When my airbrush get clogs with acrylics, I soak it in acetone.
It may be that you put a thick coat on that lifted the paint below.

I also have very mixed results with Humbrol clear finish. I always used the spray cans and it seems to me that Humbrol just 're-organised' the quality-control department: I had already grown used to the fact that half of the cans don't spray at all (I have to lie the nozzles in a cleaner bath first and sometimes even that won't help), but now it turns out that the actual quality of the paint differs between cans. I experienced the orange-peel effect on a Revell-coat (on which I have always used a Humbrol clear coat without problems, and also a coat from a can with gloss paint suddenly gives a matt finish; wrong sticker I'm affraid...
I envy you Americans with your Future clear coats, because I have never seen something by that name in Europe. Any idea under what name it might be sold here?
Thanks in advance, regards, Gertjan

As was mentioned by the others, you have to be very careful spraying laquer over acrylic (especially!) or enamel (to a lesser degree). I'm assuming that Humbrol clear coat is a laquer since many of them are but I haven't used it myself.

When spraying a laquer over acrylic or enamel you need to make sure the first couple of coats are little more than a mist. Let them dry thoroughly before spraying more on. The mist coats will provide a barrier between the subsequent coats of laquer and the inderlying acrylic / enamel.

QUOTE: I envy you Americans with your Future clear coats, because I have never seen something by that name in Europe. Any idea under what name it might be sold here?

I think it is available in Europe, but I can't recall the name. Johnson's Kleer, perhaps.

This article lists the several different alternate brand names for Future available world wide:

http://www.swannysmodels.com/TheCompleteFuture.html

Thanks for the tips!
They were very informative.

I did try a 'mist' coat. The spray came out kind of bumpy. I put it off to a characteristic of this product, thinking it would self level. Closer inspection showed a poor finish so I layed down a heavier coat, probably causing the orange peel.
Thanks for your post Gertjan. I will probably pitch this can and stick with Future.
Thankfully this wasn't an expensive kit. Although I did buy it twice because of an earlier mistake! Shortcuts!

I use Hubrol clear (flat) all the time. It sounds to me like you did not thin it enough to get it to work properly. a near 50/50 mix with laqcaur thinner will most likely solve your problems at far as finish. You do need to gloss coat before and after decaling and let this cure 48 hours before you flat coat or any other finish. This will help your finish considerably.
Jeff

Sorry I should have been clearer. I used a rattle can for this application.

Hmm I would lightly sand the model smooth with fine sandpaper then decant the flat into your ab and thinn it more then. This might help ya out.