This particular problem may have already been addressed in the forums but I can’t find it. I had an issue using Krylon fusion gloss black paint as a base for Alclad II. I read several articles about being able to use it as a primer, however on all of my trial runs after the Alclad dried it had several cracks. The Krylon was decanted and applied with an airbrush and then allowed to cure 48 hours before painting the Alclad, and still it cracked. After running through a bottle of Alcad im pretty frustrated lol. Am I doing something wrong or is there a trick to using this stuff?
I’d switch paints. I’ve used Alclad’s own Gloss Black Base, which is what they recommend, with no trouble. I’ve also used Mr. Color gloss black with very good success.
I’ve never really understood the whole decanting Krylon thing. It seems like an unnecessary process considering there are easier/preferred paints.
Hmm. Not sure. What kind of Alcad are you trying to spray? Only the high-shines require the gloss black prime (Chrome, Airframe Aluminum, Polished Aluminum, etc.) If you’re doing any of their other colors you can use standard gray primer. I’ve sprayed Alclad for a long time now and have never encountered any issues. I’ve sprayed on acrylic, enamel, and lacquer primers (And used Tamiya gloss black as my primer with the high-shine) with no problems. That said I have never used Krylon, so that may be the issue.
The Krylon rattle can is your problem. Sounds like a bad type of paint.
Iv’e used Humbrol gloss black, Alclad grey primer and Humbrol Clear without any problems at all with Alclads.
I ordinarily use Testors black gloss enamel for undercoating alclad. I have also used a spray can acrylic black and have used auto lacquer.
For some models I then mask and paint a few panels with other colors like gray, white, or even a color, to create a slightly different tone on some panels.
When I use black as a primer, I always use Army Painter in a rattle can. These are large cans and it goes on even and smooth. Dries relatively fast and isn’t that expensive and makes a great primer to spray over.
The first few times I tried Alclad chrome I used Tamiya gloss black spray as a base. The chrome all rubbed off. Then I noticed that the instructions specified enamel gloss black and that made a huge difference.
Ken
Yeah, the better the gloss base, including polishing the plastic prior to spraying your black gloss, the better the Alclad II will come out. 
Second point to remember if you spray the very shinny Alcalds, ( Chrome etc.) you need to not handle them with bare hands or only very carefully, until you get a gloss coat ( ie sealer ) over that finish.
The “duller” range of Alclad (aluminium type colors) are more resistant to handling so less likely to rub/wear off.
did you use enamel krylon. if you did then 48 hours isnt nearly enough. give it at least 3 days, sniff it, if it still smells like paint then it isnt cured!!