Thru-hulls

Discussions about Cape Dory, Intrepid and Robinhood sailboats and how we use them. Got questions? Have answers? Provide them here.

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Leo MacDonald CD30K

Thru-hulls

Post by Leo MacDonald CD30K »

Hi Group,
Due to once seeing a snapped nylon cockpit scupper on an Endeavor 32, my winter to do list includes replacing the nylon/plastic thru-hulls with bronze thru-hulls.
In the course of removing the manual bilge pump nylon (I guess ?) overboard thru-hull, it fell to the black top. Upon retrieving it, I found it now in TWO pieces !!! So, letting the mind wander through the "what ifs", I thought I'd post this observation for CD sailor's consumption.
It appears from the pump and thru-hull installation that this whole arrangement was original equipment or professional aftermarket .
Leo MacDonald CD30K Heather Ann
(on the hard in Groton, CT - now with three holes in the hull



macdola@gwsmtp.nu.com
Russell

The thru-hull I worry about is ..

Post by Russell »

The depth transducer, which not only is plastic, but is installed on the leading edge of the hull where it is most likely to bump something hard.

I cannot speak for other Cape Dories, but except for the two transducers, all the through-hulls on our CD 36 are heavy, bronze, Spartan hardware. They are now twenty years old, but when we serviced them this summer, all seemed good for another twenty, save the engine intake, which has been used so much that it can no longer be adjusted tighter. (This does not compromise its integrity, but required a little southern engineering to get adjusted right.)
John

Re: Thru-hulls

Post by John »

Hi Group,
Due to once seeing a snapped nylon cockpit scupper on an Endeavor 32, my winter to do list includes replacing the nylon/plastic thru-hulls with bronze thru-hulls.
In the course of removing the manual bilge pump nylon (I guess ?) overboard thru-hull, it fell to the black top. Upon retrieving it, I found it now in TWO pieces !!! So, letting the mind wander through the "what ifs", I thought I'd post this observation for CD sailor's consumption.
It appears from the pump and thru-hull installation that this whole arrangement was original equipment or professional aftermarket .
Leo MacDonald CD30K Heather Ann
(on the hard in Groton, CT - now with three holes in the hull

I read an interesting article in the premier issue of Good Old Boat magazine all about thru-hulls. It was a reprint from a Ocean Navigator magazine article. There always seems to be another thru-hull article in one magazine or another but this was different because they paid a lot of attention to the plastics. They had excellent info on the various types of plastics and nylons that are used for thru-hulls and below waterline applications.

It sort of goes without saying that the Forespar Marelon fittings being glass filled are the strongest. They are UL and ABYC approved. They had to pass stringent load and shock testing and per the article were put on a par with bronze as far as sea worthiness goes. Article or no article...myself, I'll stick with bronze for thru-hulls, for those that prefer the non corossive, then it's all Marelon!

I imagine your nylon or plastic one broke because it was brittle from UV degradation.
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