Join Date: Feb 2000
Location: Annapolis, Md
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Anyone change a thru-hull in water?
Because sealants don''t work well against wet surfaces, it is next to impossible to do a permanent installation of thru-hulls (by that I am assuming you mean the thru-hull fitting itself and not just the seacock) while in the water but here are a couple suggestions. First if you are only replacing the seacock, it is not too hard to replace a seacock by putting a plunger over the thru-hull or plugging the thru hull with an ideally rubber plug (wood swells up and gets to be next to imposible to remove).
There was a fellow on another BB who talked about replacing a thru-hull by getting a large sheet of rubber roll roofing and essentially taping it over the thru hull with a large bulge in the material. He used an industrial tape that was made for use under water. He described taping the bottom and sides with this tape and leaving lots of slack, so there was a big pucker in the middle. He then put the new exterior part of the thru hull into this pucker from the top and taped the top shut. He then removed the old thru hull which dropped into rubber roofing protected area.
He said a lot of water comes in and maneuvering the fittings was a real pain in the butt. Once the old thru-hull is out then manuever the new thru-hull into place. He used a flat piece of rubber as a gasket rather than caulking the new thru hull into place. This rubber gasket had a hole in the middle that fit snug around the thru-hull shaftand that was installed against the flange and held in place with silicone that was applied and allowed to set before the thru hull was placed underwater in the rubber membrane.
The new thru hull was manuevered into place and the nut applied from the inside of the hull. He had put a foot or so long piece of polypropelene line through the thru hull fitting to give him something to hold onto as the nut was installed. Once the nut was turned down as far as he could from the inside, a plug was inserted in the new thru hull and then the top of the rubber pouch was untaped from the outside. Lost of water poured in while they finished tightening the nut. Once the thru hull was tightly installed it continued to weep a little. Then rubber was removed from the outside, a plug was installed in the thru-hull from the outside and the interior plug removed so the seacock could be installed. I believe this was an enine intake and it allowed the fellow to motor to where he could haul out for a permanent repair. He noted that he had problems with bottom paint damage, marine growth and later with paint adhesion where the tape had been.
The propshaft is probably the hardest of the collection of underwater repairs that you list because that aften means removing the rudder as well.
All that aside, it would sure be a lot easier to haul out and do this work one time right and not have to worry about it. But of course that costs money.
The bowsprit should be easy enough to replace. Bowsprits were traditionally Spruce, Fir or Ash in that order. Fir is the most rot resistant and most readily available in large pieces today. If you do not feel comfortable making the new sprit yourself, you should be able to take the pieces of the old sprit up to George Luzier in Sarasota and have him make one for you. In the Florida climate, if you are feeling flush and adventurous, and are not as concerned about aesthetics, you might make a new sprit from aluminum tubing which is comparatively inexpensive to purchase but more way more expensive to fabricate.
Of course, you probably won''t take any of this advice because I once happened to recommend a list of less than $100,000 yachts to someone who asked for a list of under $100,000 yachts.
Good luck to you.