Ball Valves on Through-Hulls
Maine Sail says, “It's funny that the only person who claims to have re-threaded a thru-hull to NPT is a non-registered poster who has only ever had ONE post according to the search tool..”Maine Sail has a history of implying that a poster must be registered to have credibility. Does a poster need to have chronicled an extensive number of posts like Maine Sail to have credibility, I think not.I think the intent of this forum is to share our collective knowledge so we all can be better sailors. Ross, thank you for your post explaining what a Black Locust Clamp is and how to make one. If I had this knowledge back when I cut NPT on the through-hulls I would have made and used this clamp. I used a piece of steel flat stock that fit inside the through-hulls to keep them from spinning during threading, with a similar affect as the step wrench photo Maine Sail posted. I used basic threading dies with a ratchet-handle to make threads. You also mentioned “notch sensitivity” in another post. This is what I consider the weak point of a valve mounted on the end of a through-hull. We know about the affects an unsecured alternator had on a through-hull. This is why I do not stow unsecured gear near through-hull/valves, notch sensitivity. Hunter put valves, without flanges, on the end of through-hulls for many years. My ’82 H-33 came with gate-valves on the through-hulls. This flange-less valve system probably saved time and money. Is it the most dependable system for use below the waterline, NO. I think a proper seacock through-bolted is the best.So, this begs the question, why did I use ball-valves? It saved time, money, and has worked for many years. It is a production boat after all. AkulaPS: I think Maine Sail’s through-hull article with photos is well done. I commend you for emphasizing the hazards associated with combining NPS and NPT.