Rob at Epoxy-resins.co.uk sent me a speedy reply.
He said the mix at 3 to 1 wont set.
However he also said if I put a coat of properly mixed 2 to 1 over the top it might help it to cure.
Its a bit of a judgement call and not really anyone can make without looking at the boat.
I guess if I go ahead and paint over and it does not work it will eventually delaminate. But the structurally important repairs were the first things I did and were mixed properly and are strong.
Its only when im sanding the deck and it smears I know theres a problem.
Im going to do a light sand with the belt sander, then smooth off a bit with an orbital sander, then paint over with epoxy.
Id recommend Epoxy-resins.co.uk
Rob was a big help and the "boat builders starter kit" is excellent and contains everything I needed inc gloves and mixing cups.
THe mixing ratio is printed clearly on both the resin bottle and the hardener.
Im really disgusted that ive made such a school boy error, but im putting it down to the learning curve.
Regarding the epxy csm discussion.
I personally would not mix epoxy and polyester as poly contracts.
Things have come on a bit since I was 8 (29 years ago). With boat building, where youre trying to bond to wood, epoxy is definitely the best material.
Ive asked Rob to comment on whether the 300 gsm matt i bought elsewhere is suitable for his epoxy. Im pretty sure he'll say its fine but Ill let you know if im wrong (ive no pride left anyway).
Thanks for all the advice. I didnt even get a sense of anyone laughing their ass off. Im assuming that this is because youve got your own disaster stories. It would be good therapy for me if anyone wants to tell all here!