Can anyone assist me with a penetrating sealant that will be effective in the following circumstance?
A model outline submarine where the 4inch diameter wooden bow section slots into a 4inch diameter drainage pipe. The joint is screwed and then sealed with a rubberised gasket sealant and was a sound waterproof joint when created. I then plated the hull with shim brass sections fixed with epoxy resin. I thought that this would result in a belt and braces waterproof seal. After further work on the boat a flotation test has revealed a small leak in the joint and from the amount of water entering I guess would probably amount to no more than a pinhole. An attempt at stopping the leak on the inside with more rubberised gasket predictably met with failure.