Old Boat Nightmares #3: Gate Valves
Among the multitude of things that needed upgrading on our project boat, the cockpit drain seacocks loomed large. The wheels on the 1973-vintage gate valves were frozen open so the valves could not be closed. This is a typical problem with gate valves. The valve stems and the valve body are usually dissimilar metals, and eventually theyll corrode so that the valve sticks on the position it was left in either closed or open. Another problem is that debris often gets caught inside the valve, preventing it from closing. In short, these items have no place on a boat.
Replacing the valves was one of those jobs that I just kept putting off, until shame drove me to it. Amazingly, after Id chopped off the wheels with an angle grinder, the nearly 40-year-old valves unscrewed easily from their through-hulls; apart from being jammed open, they were in better condition than they looked, a testament to the quality of 1970s bronze.
On the other hand, the through-hulls themselves were a real chore to remove. The retaining nuts had been covered with gelcoat and that, combined with the fact that the through-hulls were well bedded into the nearly inch-thick hull laminate, meant that gentle persuasion was not the answer here. I got out the Sawzall andfrom outside the boat poked the blade into the through-hull and made a series of cuts around its circumference, taking care just to slice through the bronze and not to bite too deeply into the surrounding fiberglass laminates. Then I just tapped the pieces out with a hammer.
The new through-hulls and seacocks are Marelon no more corrosion for me!