Refinishing foils

I would do any major filling work with an epoxy filler. Take a bit of time to flat that back properly. Then go on with a high build primer/ surfacer. This ideally would be an epoxy ( SP Systems used to one called Hibuild, Awlgrip have one as well) it might be tricky to get a small pack retail nowadays so ask the local car paint supplier what he has. 2 pack epoxy ideal, but a 2K acrylic one would probably do OK. When applying this it doesn't matter what it looks like as most is coming back off. This primer surfacer is the key because when that is flatted back which should be easy as it sands well. ( at least 50% of it removed) you will have a perfect finish for a 2K top coat. For this an acrylic car paint will be fine.

Spray from Halfords isn't the most durable of course. I tend to use a different colour every time So I know where I am rubbing down, but I'm quite happy with multicoloured foils. Few others are! With daggerboards you have to watch out you don't add extra thickness.