MY GULFSTAR 50 HAS PLASTIC STYLE THRUHULLS. I AM GOING TO REPLACE THEM THIS WINTER AND WONDER IF ANYONE HAD ANY COMMENTS ON PLASTIC OR BRONZE? I AM PLANNING ON REPLACING WITH ORIGINAL TYPE EQUIPMENT UNLESS SOMEONE CAN GIVE ME A BETTER SOURCE.
I have Marelon (reinforced plastic) thruhulls and seacocks on my Laser 28 and they are now 15 years old and still work quite well. Obviously, there are various types and grades of plastic and so not all plastic secocks are made equal. Traditional bronze tapered plug type seacocks are more durable (if you can avoid electrolysis problems) and can be rebuilt almost indefinitely but do require more maintenance than ball valves. One word of caution there are bronze ball valves out there that are not really intended for use on seacocks.
the traditional tapered plug bronze seacocks on my cape dory are going strong in their 21st year. Cape dory, alas, is no longer with us, but Spartan (who manufactured the seacocks) is still in business. I would recommend their seacock to anyone.
Maintenance isn''t that onerous, as long as the seacocks arent buried deep in a locker. Just disassemble them, clean, grease with a high quality waterproof grease (its the grease that actually seals out the water) and reassemble. do not over tighten, as this only forces out the grease. Needless to say, only service them when the boat is hauled.