gloss coat

Yep, I agree with all of the above. My suspicion is that it may have been two things:
1. The lacquer over the enamel. Mike V's got the technique. If you put it on wet, it will eat into the underlying layer.
2. I suspect the enamel may not have been fully cured. A quick way to tell if they are done curing is to 'smell' the finish. If you can smell solvent in any way, chances are it's not done curing yet. Certain colors take a LONG time to cure. Like Black and Silver... I've had a couple of items take up to 2-3 weeks before I was confident they were fully cured.

Sorry to hear your frustrating news. Hopefully someone else will learn from it too...

Murray

HEY,
I also suggest the Krylon. I use it all of the time and it works great on the testors enamels. I dont know how it works on laquers, so you may have to test it on a scrap peice. Have fun!

Randy

To get lacquer to go over enamel without it affecting the enamel underneath, you have to spray the clear lacquer on in light, mist coats. After two or three light mist coats it will form a barrier that will keep the wet coats from attacking the enamel. Since you said you used spray cans I would imagine that it went on too heavy and attacked the enamel underneath.
The only way to fix it would be to strip the paint and start over.
If you don't have an airbrush to allow for the thin coats needed then I would buy an acrylic clear coat in a can and use that as your gloss coat, or use some Krylon clear which I believe is an enamel.
Be sure and test it on a scrap piece that has been painted with your enamel to make sure they are compatible.

Mike

I used enamel paint and canned clear coat from Testors. The paint was dry for at least a day and a half or two days. Was this not enough time? I've got two cars and both did this. The former was described above, the latter was dry for at least a week. I've since bought laquer paints for a future project and now wonder what you can tell me about the negative effects of mixing enamel and laquer? One more question: is there any hope for the two cars I've already botched?

Good point. Bad things can happen when you spray lacquer over acrylic...

I agree with Vinnie.

Did you spray lacquer over acrylic by any chance?

Mike

Welcome to FSM

What kind of paint did you use? Acrylic or enamel? Did you wait sufficient time for the paint to cure before you clear coated? What kind of clear coat did you use? Most of the time, cracking in clear coat will occur because the underlying paint is still curing or out gassing, thus will shift, causing cracking.