01 April 2020
Nick's right...make sure you can get the correct gelcoat from Ovi's. Might take a while at the moment.
Basic principle is to remove all the damaged material so you are working with a solid substrate. If necessary, mix up some filler paste (either gelcoat with some microfibres/colloidal silica or epoxy with similar fillers if the dent is quite deep) and fill to just below the finished surface. If you have used gelcoat to make the filler paste you can apply the gelcoat whilst the top layer of the repair is still tacky. If it's epoxy, you'll need to let it cure properly and then abraid the surface to ensure there will be a mechanical bond between the two different systems.
Apply the gelcoat as a couple of thin coats rather than one thick one which might sag or bubble. If you have some thin plastic film (report covers always work well!) you can tape that over the repair whilst it sets; electrical tape will work fine if that's all you have. If you leave the gelcoat open to the air whilst it cures it will harden but you will be left with a slightly tacky surface layer that you will have to remove.
Once you are happy that the repair is filled (ideally, slightly over-filled) it is down to elbow grease and various grades of wet & dry.
There are numerous YouTube tutorials that can provide pictures to save a thousand more words. All the yacht principles are the same as the dinghy principles except that where they are using a 40 grit disc on an industrial grinder, you might want to be using the corner of a piece of 120 grit wet & dry!
Don't panic if the first attempt isn't too pretty; you can always Dremel it out and start again.
Last Edited 01 April 2020