How to fix cracked/lifted lacquer on roof?

[TroubledSoul]

The lacquer on the roof of my track car is cracked and lifted in places. It now lets water in underneath it. Is there a way I could rectify this with a sander and a rattle can of lacquer that would look "acceptable" or does it need a more thorough job doing?

[paintman]

There is an adhesion problem.
You might find you get to the edges of the panel before the lacquer stops flaking off.
The sanding will affect the colour coat.
Spraying clear over it will not make a lot of difference to its post sanding appearance.
There may be a reaction between the clear & whatever you're spraying it onto.
I'd suggest sanding all the finish off - back to bare metal (or GRP depending what the car is) and starting from a clean sheet.

[Dr Doofenshmirtz]

It depends how good you want it to look. I've used a power washer to remove all loose/peeling lacquer, and then just lacquer over - 2k is best.
Results were better than before, but the ridge between old lacquer and new lacquer is still there.
Trouble is, if you attempt to sand it smoother there's a big risk you'll go through the much softer top colour coat into the primer, thus ruining your weekend and requiring a full respray.

[TroubledSoul]

Well it's only the roof, and it's between two rubber gutter strips which act as a nice border for the edge of any paintwork to sit under, but yeah it sounds like stripping the panel and giving it a spray is the best option. Something else for me to learn!