High John. Yes I too have had this problem and have written an article on the subject for the hopefully next edition of the magazine.
Look out for “pressure testing your hull”! As this is what Hartley’s said I should do, But with no explanation of how to do this! I think you will need some polyester adhesive from Hartley’s to bond the 2 hulls together around the self bailer if your problem is the same as what I had. If you are having a problem about the test ask Simon the editor to pass on to you my details and I will send the process I used to you. B.R. Dion 1716