Trying to eliminate the use of anti-fouling paints

Discussion in 'Boat Design' started by Cmw505, Jul 26, 2019.

  1. sdowney717
    Joined: Nov 2010
    Posts: 852
    Likes: 32, Points: 28, Legacy Rep: 274
    Location: Newport News VA

    sdowney717 Senior Member

    I would coat the wood with polyurethane, such as Loctite Pl roof and flashing. Did it on my boat, been great. mix in 30% milled fiberglass fibers. Smooth it on in layers with a 6 inch putty knife. Coat ends up about 1/8" thick.

    No, it wont stop marine growth, but yes the hull is solid and dry and no borers can get in.
    Honestly, its like coating them bottom with a truck tire.
    https://goo.gl/photos/Y876jwe1jceTp9Zz6

    In 2006, I did a complete reframe. For plank caulking, I used Loctite PL Premium polyurethane Construction adhesive (3x strength tan color) mixed with sawdust. It swells as it cures, it is waterproof. It locks the plank wood together. It remains slightly flexible without cracking. It does not come out of the seams.
     

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  2. gonzo
    Joined: Aug 2002
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    Location: Milwaukee, WI

    gonzo Senior Member

    Caulking planks is not like caulking a bathtub. PL is the wrong product. You should pound in cotton to lock the planks and create a panel. Otherwise, the fasteners are going to come loose from elongated holes and too much stress.
     
  3. sdowney717
    Joined: Nov 2010
    Posts: 852
    Likes: 32, Points: 28, Legacy Rep: 274
    Location: Newport News VA

    sdowney717 Senior Member

    Its been fine since 2006. it was built in 1970. If I had not rescued it, it would have gone to the dumpster.
    I had a few people respond like you , saying rip it all out, glad I did not listen to them.
    My hull stays strong and solid, and theirs falls apart, next thing its in the dumpster, while my woodie is still going out on the bay. Someday I may have one of the last Eggharbor 37 wooden cabin cruisers. Because I know how to make things last. What happened to all the wooden boats maintained the old ways, most of them are gone.

    I also ripped out all the old tech failing cracked white putty and strings in the above water line planks, and caulked with DAP Dynaflex 230 latex caulk. Guess what no more leaks, no more water wicking in between planks to cause rot, no more being able to see through plank seams. That stuff dries to a hard rubber. And locks the planks better than any pounded caulking, which eventually fails. All those old methods fail,and they fail unbeknownst to the owner and then it leaks and then it rots. And then all those laughing fools pay to have their boat crushed and go to the landfill. Usually their boat sinks in the slip, somethin never has.
     
    Last edited: Jul 28, 2019
  4. gonzo
    Joined: Aug 2002
    Posts: 13,418
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    Location: Milwaukee, WI

    gonzo Senior Member

    I definitely disagree. Boats that get light use or stay at the dock may let you get away with it. However, DAP 230 will not lock the seams like cotton does. The problem is when boats don't get properly maintained or repaired. Wood rots when the moisture is about 20 and 50%, the ideal range is 25 to 30%. When the moisture is over 50% the fungi will not grow either. There is also degradation due to fermentation, which is caused by yeast and that can happen with higher moisture content. However, planks do not rot from moisture getting in between. The moisture swells the planks and makes them lock. You claims to being the only only one to know how to make things last and every shipwright in the world is a laughing fool make you seem rather narcissistic.
     

  5. KeithO
    Joined: Jul 2019
    Posts: 103
    Likes: 10, Points: 18
    Location: Michigan

    KeithO Senior Member

    Thread hijack.....
     
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