The WEST Epoxy bonds better to the "cured polyeser" then "new polyester" does ... according to the research I've seen. The issue of getting Gelcoat to bond to epoxy is the "Amine Blush" ... and you need to have "wax additive in the gelcoat as gelcoat is made to cure in an AIRLESS enviornment Ie: in the mold. With out wax and exposed to the air ... gelcoat never cures completely but will remain slightly "tacky".
The "Amine blush" issue is solved by allowing 3-4 days curing time before gelcoating w/ UV exposure ie: sunlight.
Now you will need several layers of cloth ... if you wish to apply the epoxy w/ cloth in one continous process I would start w/ wider cloth and work towards narrower cloth. Apply epoxy let it tack up ... apply a layer of cloth,and smooth out ... apply a coating of epoxy ... let tack up ... apply next layer of cloth ... etc etc.
Now if you have time you can work from narrow to wide cloth, but this requires allowing the epoxy to cure completely ... sanding ... next layer ...
I've done this more then once ... and if you are racing every weekend you get good at doing quick/fast processes.
Harry Murphey
H18mag/P19MX