Forums › General Discussion › seal off/plug thru hull

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    • #68836
      cbboat
      Participant

      What is the safest way to seal off a thru hull. I have one that I intend to remove next haul-out. Should the hole be plugged with something or filled with glass/epoxy?

      Thanks

    • #80444
      quent
      Participant

      A couple questions:
      Is there a seacock on the through hull?
      If so, what’s it’s condition?
      Is the through hull plastic or bronze?
      Is it above or below the waterline?
      Location?
      Quent

    • #80445
      Tor
      Participant

      I removed 7 thru-hulls when I was upgrading my 424. It
      was one of the few occasions when I elected to pay a
      professional, to be sure it was done perfectly. Using
      an angle grinder and plenty of experienced finesse, he
      feathered the fiberglass out 3″ or 4″ radius from the
      hole on the outside, feathered so that the ‘glass was
      very thin at the edges of the original hole and
      thickest at the feather’s perimeter of the feather.
      Then he cut widening circles – from the hole size to
      the extreme perimeter size – of mat & maybe some
      roving, plus maybe the last 1 or 2 were cloth. Taping
      some backed wax paper over the original hole on the
      inside, the then wetted in each successively larger
      cutout, building outward from the hole on the outside
      of the hull, each patch overlapping a little move onto
      the feathered ‘glass of the hull, until the last 6″-8″
      circle of cloth was in place. He used polyester resin
      for this. Once it set up, he sanded it smooth, then
      coated with gel coat. It was a thoroughly professional,
      very strong job that will last as long as the hull
      does. To my knowledge this is the (only?) right way to
      seal a big hole like a thru-hull.

      Have fun,

      Tor


      Silverheels, P-424 #17
      http://www.silverheels.us


      Quote:

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    • #80446
      Anonymous

      Here’s some video explaining it similar to the way Tor had his done. There are a few video’s to get through and he can be a tad annoying but I feel he is doing a very adequate repair. it’s not rocket science. I plan to be doing up a few holes in the next few weeks. I’ll grind a small repair from the inside after I do a job more to the likes of Tor.

      http://www.youtube.com/watch?v=gGr-OsUdf0A&list=PLV97GZkHhpHOKR_y03zg98Cxe6VLOq83B&index=2

      Ken

    • #80447
      madsailor
      Moderator

      I do my own repairs, I use epoxy and biaxial cloth (two axis straight lines
      with mat between and on one surface). I grind most out of the outside of
      the hull, and some out (for two layers) on the inside. There is some
      discussion about whether to start with the small circles first or the
      larger ones. I see the point of them both, but I’ll do the larger ones
      first from now on. I do the inside ones and let them start to set, then
      start with the outside ones. If you have to wait, then a touch of sanding
      on the outside before an acetone wipe will do the job.

      As Tor says, not rocket science.

      Bob

      On Thu, Jan 2, 2014 at 6:50 AM, Page Two wrote:

      Here’s some video explaining it similar to the way Tor had his done. There
      are a few video’s to get through and he can be a tad annoying but I feel he
      is doing a very adequate repair. it’s not rocket science. I plan to be
      doing up a few hols in the next few weeks. I’ll grind a small repair from
      the inside after I do a job more to likes of Tor.

      http://www.youtube.com/watch?v=gGr-OsUdf0A&list=PLV97GZkHhpHOKR_y03zg98Cxe6VLOq83B&index=2

      Ken


      Ken and Vicky # 91……Writing a New Chapter Page by Page in an Old Book.

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      —
      Bob Fine
      s/v Pelican
      Pearson 424 Hull #8
      http://thesailinglife.blogspot.com
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    • #80448
      Tor
      Participant

      You know, my guy may have feathered back and built up a
      little on the inside, as well. It was 7 years ago and I
      may not be recalling it perfectly.

      Tor


      Silverheels, P-424 #17
      http://www.silverheels.us


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    • #80449
      madsailor
      Moderator

      It doesn’t matter that much, Tor, because the loading around those spots is
      well below the capacity of the material that’s being put in there. To be
      honest, you could put two thicknesses of mat there, well wet out, and it
      would hold for the life of the hull. Where all the through hulls are, the
      strength is far above the static or dynamic requirements, at least over the
      area covered by the hole.

      Bob

      On Thu, Jan 2, 2014 at 7:30 AM, Silverheels wrote:

      Quote:
      You know, my guy may have feathered back and built up a
      little on the inside, as well. It was 7 years ago and I
      may not be recalling it perfectly.

      Tor


      Silverheels, P-424 #17
      http://www.silverheels.us


      Quote:

      Original Message


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    • #80450
      Anonymous

      Bob …What about redoing the gelcoat below the waterline, is it needed to be done if using epoxy? Tor, I’d bet your guy did. Of course I’ll be chatting up Dave, the fiberglass guy at Tiger Point Boat Yard too.
      I’m getting ready to pull and rebuild as needed all my thru-hulls, along with removing and relocating a few. The new compost head is done and has really opened up the playing field below the sole. I haven’t got the whole plan layed out yet but am anxious to have her out of the water so I can get started. I wish I had more time but I really want to do some cruising this season.

      Ken

    • #80451
      madsailor
      Moderator

      If you use epoxy, you don’t need new gelcoat. If you use polyester, you
      need to coat with epoxy or gelcoat.

      Best,

      Bob

      On Thu, Jan 2, 2014 at 8:54 AM, Page Two wrote:

      Bob …What about redoing the gelcoat below the waterline, is it needed to
      be done if using epoxy? Tor, I’d bet your guy did. Of course I’ll be
      chatting up Dave, the fiberglass guy at Tiger Point Boat Yard too.
      I’m getting ready to pull and rebuild as needed all my thru-hulls, along
      with removing and relocating a few. The new compost head is done and has
      really opened up the playing field below the sole. I haven’t got the whole
      plan layed out yet but am anxious to have her out of the water so I can get
      started. I wish I had more time but I really want to do some cruising this
      season.

      Ken


      Ken and Vicky # 91……Writing a New Chapter Page by Page in an Old Book.

      _______________________________________________
      maillist mailing list

      https://pearson424.org/mailman/listinfo/maillist_pearson424.org

      —
      Bob Fine
      s/v Pelican
      Pearson 424 Hull #8
      http://thesailinglife.blogspot.com
      _______________________________________________
      maillist mailing list

      https://pearson424.org/mailman/listinfo/maillist_pearson424.org

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    • #80452
      cbboat
      Participant

      Thanks for the info, especially all ya’ll who have done this before. I figured tapering hole and patching was the way to go.

      Quent:
      Is there a seacock on the through hull? no, previous bozo put a ball valve directly on a mushroom thru hull.
      If so, what’s it’s condition? seems ok, but hard to get to and not really needed.
      Is the through hull plastic or bronze? bronze
      Is it above or below the waterline? below
      Location? waaayyyy down in port cockpit locker, real PITA to get to.

      I don’t want it anymore, too hard to get to, broken, bad installation, used for generator and I tee’d of engine seacock with ball valves, since i don’t run them simultaneously.

    • #80455
      quent
      Participant

      Lots of good advice here. Hole has got to go. I agree with Tor, find a good fiberglass guy, especially if the hull isn’t real thick at that location. Good advice above on woven fiberglass material. Don’t use mat.
      Epoxy will stick to the hull better than polyester which forms a relatively weak secondary bond, hence the need for a long taper for contact area.
      Clairebuoyant has 22 through hull openings, counting the transom. Gives me something think about on a long night off shore.
      Quent

    • #80456
      Tor
      Participant

      Pearson doesn’t sound like a Swiss name, but he sure
      had a penchant for the cheese. 22 thru-hulls in a 42′
      boat?! Crazy. I think Silverheels had nearly that many
      when I bought her, but after my anti-hole rampage it’s
      like this:

      Below-Waterline T-hull, Starboard Side #1


      Intake to seawater intake manifold, which feeds the
      following:
      – galley sink
      – watermaker
      – toilet
      – anchor/foredeck wash-down
      – bilge hose-down

      Below-Waterline T-hull, Starboard Side #2


      – engine raw water intake

      Below-Waterline T-hull, Port Side #1


      – galley sink drain

      Below-Waterline T-hull, Port Side #2


      – toilet discharge

      That’s 4 holes below the waterline, plus a
      forward-scanning sonar thru-mounted.

      There are another 6 thru-hulls above the waterline,
      plus a small hole high in the transom for the propane
      locker drain.

      So, 10-12 total, depending how you count. Not ideal,
      but an improvement.

      Tor


      Silverheels, P-424 #17
      http://www.silverheels.us


      Quote:

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    • #80457
      quent
      Participant

      Some t-hulls in Clairebuoyant are overcome by events. We no longer have water cooled refrigeration or a watermaker, so that’s four. If we pull out the dc kubota genset that’s two more. Hate to give up our massive investment in bronze seacocks, but all for the greater good.
      Got my doubts about the sea chest concept. Seems like a lot of plumbing below the waterline. Recently saw a very pretty Tayana 48 with a custom fabricated stainless steel sea chest box that failed at a weld. Sort of an all the eggs in one basket problem maybe.
      Quent

    • #80458
      Tor
      Participant

      I suppose a sea chest or seawater intake manifold is a
      matter of preference and opinion. I see more potential
      danger from 4 or 5 or 6 extraneous thru-hull fittings –
      lots of unnecessary holes in the bottom – than from a
      single, properly made and maintained distribution
      chamber. Whatever floats your boat, I guess… and
      keeps it floating.

      Tor


      Silverheels, P-424 #17
      http://www.silverheels.us


      Quote:

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    • #80459
      Anonymous

      I really like the idea of getting rid of as many holes in the boat as possible and I’d like to do major improvements to a distribution chamber as Tor puts it but I also want to do some cruising. The salt water manifold (for lack of a better word) that I do have on board is in the aft lower compartment under the captains berth, just aft the hot water heater. I’d like to move it right out of there and leave space for a future battery relocation but that over-all project should wait till I get some use out this old girl, to make sure I fall head over heels in love with some cruise time gone by.

      I’m planning on a month on the hard……we’ll see how the hustle goes week by week.

      Happy New Year everybody!
      Ken

    • #80460
      skipmac
      Participant

      Hi Tor,

      I recall seeing a photo of your seachest on your website but last time I looked the photo eluded me.

      Is it still there? Can you post a link or directions to find it. Want to do a similar setup and don’t see any point in reinventing that particular wheel.

      Thanks
      Skip

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