One seacock was in need of replacement. The valve arm was corroded and there was clearly evidence of leaking joints. Although the only definite thing identified on the survey was the leaking ad corroded valve I decided to replace the thru hull fitting. It took me a while to realise that a seacock is often made up of two parts. A thru hull fitting and a ball valve. Removing the ball valve was easy. The thru hull fitting was not. More photos on PBO forum reader to reader resulted in the suggestion that I made a step wrench from an old socket and use it to extract the fitting from the outside by unscrewing it. Armed with a huge torque wrench and the modified socked I set about unscrewing it. One quarter turn was all that was required to strip the lugs that the modified socket was keyed into. Plan B. This was identified as using a saw to collapse the fitting from the inside. This again was not as easy as I thought. It turned out there was a secret nut bonded into the hull that the fitting was threaded through. This required gouging out using a dremmel. Once extracted there was a hole that needed filling with epoxy. The new fitting was greased and put in place and then viscous epoxy was poured in to make a close fitting. I also took the opportunity to fabricate a big GRP washer to distribute the load. So far this all seems to be going to plan. More later.... Click on the photo on the right to see more.