I just got the two answers tumarI problem. I like the idea of coating the hull from the inside. I think that would have been wise. However, I had already put on two coats of oil based poly. I added one more coat of poly and then I put it in the tank. it didnt leak. Im still thinking about adding the inside coating And will do that if it leaks again. Thanks for your help.

HI lenzmeg

Welcolm to the forum.
First what Vickers said, seel the hull, I do this with thinned epoxy coating, I get mine from easy composites in Stoke, (they do mail order) it is runny from the bottle but I add a small amount of meths as a thinner, poar into the hull and rotate the hull coating the insides all over, (dont put to much in at one go) you can always add some more but its a sod to get excess resin out!!!! (guess how I discovered)

Second. is the finnish on the hull OK? if not sand back lightly and re-paint, I use Halfords rattle cans. Acrilic. you dont usualy get a reaction!!!! if the finnish is ok, use Halfords clear coat again as a rattle can. Very light sanding 1200 grad wet and dry, just to key the surface. clean with thinners to remove any grease or finger prints, then use a tack cloth the remove dust. 2 or 3 light coats are better than 1 thick coat. need a warm dry place to spray, back garden on a calm day but move hull inside to dry, very light sanding inbetween coats will give a superb finish.

Regards

Mark

HI without knowing what they have use on it is a bit of a hard one, you could try clear yacht varnish, but really you need too sort out the holes first, try some epoxy glue to bung the hole from the inside, hope this helps.