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  • New stringer repair idea

    After reading a lot of threads on stringer replacement, Ive come up with a possible alternative.

    Lets say you drill down into your stringers and there is moisture but no mulch or decomposed rotted wood.

    Ok, we know the moisture is not good and that delamination on the sides is pretty much a sure thing. Many folks cut the top off of stringers and the wood can simply be lifted out. You always hear that you shouldnt simply cut the tops off, removed from he wood, and replace. To a point I disagree. The wood has already delaminates or separated from the glass due to years of swelling and shrinking.

    Heres what Im thinking:

    Drill holes through top of stringer to the bottom every4 inches or so.

    Next, drill holes horizontally along the stringer every 4 inches or so. Maybe 3 rows and go all of the way through.

    Put a low temp heater or two in the boat and get air in there. Let it dry. Do one stringer at a time.

    After dry simply fill the holes. First with thin epoxy to penetrate the sides of the hole the smear thickened epoxy in the holes. San the outer skin a bit and add I layer of 1800 for a tad of added strength.

    Because the wood is usually separated from the stringer skins, I see no harm in simply cutting the tops off of the stringer, sand inner skins for tooth, soak the new stringer with epoxy, put thickened epoxy in the channel( just a tad, lather the stringer wood with thickened epoxy and glass, reinsert, then a few layers off new glass on top and a new skin over it all.

    I dont think grinding out the skins and the tabbing to hull is absolutely necessary. Some say the new core wont bond to the skins but I say the old core lost its bond years ago anyway likely. .

    To me, getting the moisture out and adding a little fresh glass could be a quick yet reliable fix as opposed to sanding for days and starting from a bare hull. Just a rainy day brain storm.

  • #2
    Why not after the boat is blocked and supported properly and level can you not cut the top of the stringer off to remove the wood clean and prep if youre not going to raise them? Thats how a transom is done and then Filled with Seacast or arjay. Once filled glass the top over again. Or, sounds to me would be better just start over. Good luck either way.
    BadMako.[br]

    Comment


    • #3
      Do what Barry suggested!

      Comment


      • #4
        quote:


        Originally posted by BarryJohnsonjr


        Why not after the boat is blocked and supported properly and level can you not cut the top of the stringer off to remove the wood clean and prep if youre not going to raise them? Thats how a transom is done and then Filled with Seacast or arjay. Once filled glass the top over again. Or, sounds to me would be better just start over. Good luck either way.



        There was recent discussion about Arjay disclaiming that their product was not for stringers. I don't recall why but something to look into. There is also debate that the core is simply there to just provide support to the laying glass for the stringers and it's the glass that gives the strength not the core, similar to foam filled stringers. Of course I think the stringer needs to be engineered for this and I'm not an engineer by any means but they are questions to look into. There's multiple ways to skin a Hog which proves very true with boats.
        1978 Mako 25 - Blind Hog
        1985 Mako 20c - sold
        Fort Walton Beach, FL
        http://www.classicmako.com/forum/top...TOPIC_ID=42841

        Comment


        • #5
          I had a naval architect look at my stringers when I was working on a 21 I had. With the amount of glass laid over the top of the wood and tabbed to the hull, he stated the wood was not really even needed. I believe I had somewhere between 1/4" and 3/8" of glass on either side of the wood.
          \'07 Mako 19 bay, sold[br]\'76 Mako 21, sold[br]\'77 Mako 21, dump[br]\'77 Mako 22, sold[br]\'80 Mako 23 WA, sold[br]\'82 Mako 21, sold[br]\'85 Mako 254 currently[br]\'78 J24 USA 292 (sold)[br]\'05 Melges 32 racing sailboat

          Comment


          • #6
            quote:



            There was recent discussion about Arjay disclaiming that their product was not for stringers. I don't recall why but something to look into. There is also debate that the core is simply there to just provide support to the laying glass for the stringers and it's the glass that gives the strength not the core, similar to foam filled stringers. Of course I think the stringer needs to be engineered for this and I'm not an engineer by any means but they are questions to look into. There's multiple ways to skin a Hog which proves very true with boats.



            I wasnt aware of Arjay being an issue. Havent messed with it in sometime. But Im sure there is other material out there he could use. Like an 8lb pour foam. Hard as a rock and doesnt expand much. Then whatever does expand just gring the top and glass. They do that with rotten floors so that really could be an option. Thoughts?
            BadMako.[br]

            Comment


            • #7
              quote:



              There was recent discussion about Arjay disclaiming that their product was not for stringers. I don't recall why but something to look into. There is also debate that the core is simply there to just provide support to the laying glass for the stringers and it's the glass that gives the strength not the core, similar to foam filled stringers. Of course I think the stringer needs to be engineered for this and I'm not an engineer by any means but they are questions to look into. There's multiple ways to skin a Hog which proves very true with boats.



              I wasnt aware of Arjay being an issue. Havent messed with it in sometime. But Im sure there is other material out there he could use. Like an 8lb pour foam. Hard as a rock and doesnt expand much. Then whatever does expand just gring the top and glass. They do that with rotten floors so that really could be an option. Thoughts?
              BadMako.[br]

              Comment


              • #8
                I used arjay in my transom and would not think twice about using it again. I still have several samples from my left over pour, one plug that has been sitting in water since July 2013 and it's hard as a rock. As for use in the stringers, this was just mentioned in a discussion and I have not done any research on it so take it for what's worth.
                quote:


                Originally posted by BarryJohnsonjr


                quote:



                There was recent discussion about Arjay disclaiming that their product was not for stringers. I don't recall why but something to look into. There is also debate that the core is simply there to just provide support to the laying glass for the stringers and it's the glass that gives the strength not the core, similar to foam filled stringers. Of course I think the stringer needs to be engineered for this and I'm not an engineer by any means but they are questions to look into. There's multiple ways to skin a Hog which proves very true with boats.


                I wasnt aware of Arjay being an issue. Havent messed with it in sometime. But Im sure there is other material out there he could use. Like an 8lb pour foam. Hard as a rock and doesnt expand much. Then whatever does expand just gring the top and glass. They do that with rotten floors so that really could be an option. Thoughts?



                1978 Mako 25 - Blind Hog
                1985 Mako 20c - sold
                Fort Walton Beach, FL
                http://www.classicmako.com/forum/top...TOPIC_ID=42841

                Comment


                • #9
                  I used arjay in my transom and would not think twice about using it again. I still have several samples from my left over pour, one plug that has been sitting in water since July 2013 and it's hard as a rock. As for use in the stringers, this was just mentioned in a discussion and I have not done any research on it so take it for what's worth.
                  quote:


                  Originally posted by BarryJohnsonjr


                  quote:



                  There was recent discussion about Arjay disclaiming that their product was not for stringers. I don't recall why but something to look into. There is also debate that the core is simply there to just provide support to the laying glass for the stringers and it's the glass that gives the strength not the core, similar to foam filled stringers. Of course I think the stringer needs to be engineered for this and I'm not an engineer by any means but they are questions to look into. There's multiple ways to skin a Hog which proves very true with boats.


                  I wasnt aware of Arjay being an issue. Havent messed with it in sometime. But Im sure there is other material out there he could use. Like an 8lb pour foam. Hard as a rock and doesnt expand much. Then whatever does expand just gring the top and glass. They do that with rotten floors so that really could be an option. Thoughts?



                  1978 Mako 25 - Blind Hog
                  1985 Mako 20c - sold
                  Fort Walton Beach, FL
                  http://www.classicmako.com/forum/top...TOPIC_ID=42841

                  Comment


                  • #10
                    Sailor out of curiosity why did Arjay say not for use in stringers?

                    The idea that the wood core represents no structural benefit is iffy to me.
                    ROGUE I[br]1978 235 CC[br]Newburyport, MA[br]ROGUE II[br]1987 17\' Montauk[br]Camden, ME[br]

                    Comment


                    • #11
                      Sailor out of curiosity why did Arjay say not for use in stringers?

                      The idea that the wood core represents no structural benefit is iffy to me.
                      ROGUE I[br]1978 235 CC[br]Newburyport, MA[br]ROGUE II[br]1987 17\' Montauk[br]Camden, ME[br]

                      Comment


                      • #12
                        Sailor out of curiosity why did Arjay say not for use in stringers?

                        The idea that the wood core represents no structural benefit is iffy to me.
                        ROGUE I[br]1978 235 CC[br]Newburyport, MA[br]ROGUE II[br]1987 17\' Montauk[br]Camden, ME[br]

                        Comment


                        • #13
                          I was on there site today and saw Arjay displaying a stringer repair.

                          https://www.arjaytech.com/index.php/filleting/stringers

                          Not sure. Not much info, but no discussion of not using. I assume 'flexibility" along with rigid motion has to come into play. There is a reason skyscrapers sway with the wind[]
                          quote:


                          Originally posted by Sailor


                          quote:


                          Originally posted by BarryJohnsonjr


                          Why not after the boat is blocked and supported properly and level can you not cut the top of the stringer off to remove the wood clean and prep if youre not going to raise them? Thats how a transom is done and then Filled with Seacast or arjay. Once filled glass the top over again. Or, sounds to me would be better just start over. Good luck either way.



                          There was recent discussion about Arjay disclaiming that their product was not for stringers. I don't recall why but something to look into. There is also debate that the core is simply there to just provide support to the laying glass for the stringers and it's the glass that gives the strength not the core, similar to foam filled stringers. Of course I think the stringer needs to be engineered for this and I'm not an engineer by any means but they are questions to look into. There's multiple ways to skin a Hog which proves very true with boats.


                          1982 Whaler Montauk 90HP( sold)[br]1977 25 Mako CC 225HP

                          Comment


                          • #14
                            I was on there site today and saw Arjay displaying a stringer repair.

                            https://www.arjaytech.com/index.php/filleting/stringers

                            Not sure. Not much info, but no discussion of not using. I assume 'flexibility" along with rigid motion has to come into play. There is a reason skyscrapers sway with the wind[]
                            quote:


                            Originally posted by Sailor


                            quote:


                            Originally posted by BarryJohnsonjr


                            Why not after the boat is blocked and supported properly and level can you not cut the top of the stringer off to remove the wood clean and prep if youre not going to raise them? Thats how a transom is done and then Filled with Seacast or arjay. Once filled glass the top over again. Or, sounds to me would be better just start over. Good luck either way.



                            There was recent discussion about Arjay disclaiming that their product was not for stringers. I don't recall why but something to look into. There is also debate that the core is simply there to just provide support to the laying glass for the stringers and it's the glass that gives the strength not the core, similar to foam filled stringers. Of course I think the stringer needs to be engineered for this and I'm not an engineer by any means but they are questions to look into. There's multiple ways to skin a Hog which proves very true with boats.


                            1982 Whaler Montauk 90HP( sold)[br]1977 25 Mako CC 225HP

                            Comment


                            • #15
                              Heres another thought. When I rebuilt my 21 I foamed the entire hull except the beige. I put in a bulkhead back there. How flexible can a hull be when the entire hull is foamed to underside of floor......with 4lb foam at that. I wonder if foaming the entire hull with 4lb could reduce the wear on old stringers?

                              Comment

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