I bought my 1977 C27 last summer, and after reading up on this subject, the thru hulls were the first thing I tackled over the winter while she was on the hard. One of my boatyard neighbors actually knew of someone who had one of the "vulcanos" fail (boat saved by going over the side and banging in a wood plug), so it did seem like a high priority item to me (although, on the other hand, the things did work for 32 years!).
The two main problems with the glassed in nipples are, as I understood it, 1) no real mechanical connection, and 2) the NPT thread limiting the options for valves. I must say, however, that once I cut the old vulcanos out (pretty quick and easy work with a hole saw chucked into a drill) I was impressed with how well they were stuck into the glass. Its not a big job, so I would recommend doing it at first haul-out. The one problem I found about the replacement Marelon seacocks were the limited tailpieces. Basically all I could find was a straight or right angle piece that ended in a hosebarb. I'd wanted to plumb a "T" directly into the seacock under the galley to accomodate the sink and icebox, but nothing would work, and I didn't want to go with a short piece of hose from the seack to a "T" -- that would have meant 4 clamp connections in one spot overall (too many failure points). Plus I found that the Marelon barbs are a bit small (i.e., the hose does not fit on as snugly as I'd like). In the end, I decided to just redirect the icebox hose into the bilge (I use closed icepacks most of the time anyway), and just use the galley seacock for the sink alone. Draining the icebox through the seacock was always problematic, anyway, since you had to close it anytime we were underway to avoid backing up seawater into it whenever we were on a starboard tack. Best of luck! Matthew Chachere "Bochinche" Brooklyn/Sag Harbor --- In [email protected], "steveo900rr" <stevejhu...@...> wrote: > > > The ever hated THRU-HULLS > > I plan to replace all ball valves and 1 gate valve(sink) with Marelon > ball valves. When trying to close the raw water metal ball valve the > handle came off in my hand!! If I can get the thoroughly corroded > valves off the pipe nipples without breaking them off do they really > need to be replaced with true thru-hulls? I know the idea of stowed > items rolling around and shearing off an unflanged non through bolted > thru-hull is possible, I'm sure I can avoid this. Are there other > reasons to replace? Corrosion? I have read that the pipe nipples are > NPT threads, are the Marelon ball valves the same? > >
