If you want it to look like new you need to go the full gel coat route. This is a investment in equipment that
will exceed the value of both hulls. The good part is there is nothing better to learn on than a couple
of low cost sunfish hulls. You could split the difference and go with Marine Tex on one hull and
full blown gel coat on the other for the learning experience. Please note that spraying gel coat takes
some serious protective gear. That and you'll probably brick your gel coat spray gun the first time
as you only have a 20 minute working window. If you are new to spraying best to go with something
like Rustolium Top Sides to gain experience.
While I tend to agree with this, gelcoating is a skill that can be learned to achieve results to make repairs invisible....with no extra effort. I repair both the day sailor fleets at the Boy and Girl Scout camps here in my area. I use gelcoat from the manufacturer (but unfortunately not for the Sunfishes) and don't bother extra tinting because the match is actually pretty close. Keeps the fleets looking new rather than a bunch of patched up, banged up boats. I find SeaRay Artic white gelcoat is pretty close for the Sunfishes....depending!...sometimes minor tinting or lightening it up with pure white. I've made repairs on my '69, that you don't even see without the right viewing angle and light. A matching sheen is as important as a close color match too.I think that gelcoating these hulls is overkill. These boats will be sailed by novices and are likely to get damaged in many ways.