Michiel wrote:
So, I've used one of the little repair gelcoat repair kits and
matching color was fun.

Is it also possible to get gelcoat as a paint, a form you can spray or
roll over old gelcoat, hopefully filling in little cracks and such?

Is it hard to handle? Does it come out nice?

Gelcoat can be thinned and sprayed, but it's more of a pain than
painting. Gelcoat can be rolled as-is, but thick coats will tend to run.
In either case, you need to use "finish" gelcoat, which contains a wax
that migrates to the surface to promote proper curing. Standard
"laminating" gelcoat will not cure in the presense of air. It must
either be covered with plastic or sprayed with PVA to seal it off from
air contact.

I've used wonderful epoxy and lp paints, but I thought it'd be nice if
gelcoat could be rejuvenated and sealed this way.

Just wondering in case I'd decide to cut my deck open from the top.
And yes, I did see somewhere that although epoxy adheres wonderful on
top of epoxy, the reverse is not true, so I imagine you probably can't
gelcoat an epoxy repair (not trying to feed the epoxy vs. polyester
debate here).

Gelcoat WILL adhere over fully cured epoxy repairs that are cleaned and
sanded. I do it all the time on kayak repairs.

Michiel