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    Transom rebuilding

    Just bought a 1988 Trophy 2160. I was told it was seaworthy. Hah, The transom is letting water in around the outdrive plates. I think it needs a new transom. Has any one done that on my model? Does the plywood run all the way across the transom or just where it appears to be flat ?
    Are there structural drawings available? Any info on procedure is greatly needed. I am a house builder so I have many tools to cut etc but boat rebuilding is new to me.
    Thanks you guys.

    #2
    Runs all the way across the transom.
    what you got OMC 305 with Cobra OD?
    Joon, Kathy, Jaden & Tristan
    Uniflite 42 AC, DD 671N
    93 3058 sold
    92 2855 (day boat)
    91 Fourwinns 205 (lake boat)
    Longbranch WA
    Life is Good

    Comment


      #3
      If you replace the transom, do not use pressure treated plywood, buy marine plywood only.
      marine plywood will not have any voids in the core.
      Pat says: DO-IT-RIGHT THE FIRST TIME!

      Bayliner 3870 "ALASKA33)
      Twin 350 GM power
      Located in Seward, AK
      Retired marine surveyor

      Comment


        #4
        Being a home builder you should have no problem rebuilding the transom
        My boat is a different model but there may be many similarities, take a peak at my thread for some ideas, and welcome to the club.
        Dave
        Edmonds, WA
        "THE FIX"
        '93 2556 5.7 Bravo II 2.0:1 18 1/4x19 P
        (.030 over-Vortec top end-part closed cooled)
        The rebuild of my 2556 https://www.baylinerownersclub.org/f...76?view=thread
        Misc. projects thread
        https://www.baylinerownersclub.org/f...56-gctid789773

        Comment


          #5
          When you remove the old plywood, you can cut along the top with an oscillating tool, then get some leverage and rip. Be sure to grind the old glass everywhere you are going to be laminating. Six inches is what I did. 3/4” marine fir plywood, two layers. Do your cut and fit then before you install them soak them in a catalized mix of 50/50 resin and acetone. Brush it on until it won’t take any more. Then I prefit a pair of clamps made from 4x4 sections an all thread with the all thread going through the keyhole. Assembly starts with resin and mat, roll the air out of the mat, first layer of plywood; resin, mat, roll, second layer of plywood, clamp. You should get some squeeze out of resin. The next day fill the gaps between the hull and bottom of the plywood with thickso then you can take the clamps off and put the inner layer of mat.
          I would you encourage you to glass over the edges of the cutout and especially line the drain plug hole. Any holes or screws installed in the transom need to be bedded in 4200 or the equivalent.
          P/C Pete
          Edmonds Yacht Club (Commodore 1993)
          1988 3818 "GLAUBEN”
          Hino EH700 175 Onan MDKD Genset
          1980 Encounter Sunbridge "Misty Blue" (Sold)
          MMSI 367770440
          1972 Chevrolet Nova Frame off Resto-mod in the garage
          Boating on the Salish Sea since 1948

          Comment


            #6
            Get on Youtube and search for "Friscoboater". A few years ago he totally gutted and rebuilt a Sea Ray bowrider due to transom and stringer rot. Not the same boat as yours, but the techniques are the same and he was very thorough documenting it every step of the way. It's a great series of videos to watch before you dig in to a project like this.
            Mocoondo
            2002 Bayliner 195 Capri
            Mercruiser 5.0L V8 / Alpha I Gen II
            MMSI: 338091755

            Comment


              #7
              For rolling out the air bubbles in each layer of laminate use one of these, I just bought one, very good quality, aluminum, do not buy plastic, if the roller gets clogged up then use a propane torch to burn off the cured resin.

              fiberglass laminate bubble roller

              https://www.ebay.com/itm/Fiberglass-...EAAOSwG-1WvQ6n

              Do not use too much acetone in the resin.

              I buy my rollers and paint pans from Walmart, buy the cheap green ones, 3 pack, do not try and clean fuzzy rollers just toss them.
              Keep a shallow pan to keep your bubble roller clean between layers.
              Go online and get a sheet with the info for the info for mixing resin and gel coat, buy iso resin and iso gel goat, not GP types.
              Go online and search "Fiberlay" click on quick guides at the top, click on "measurement chart" print the chart out.
              This gives the catayzation ratios with temp considerations and much more.


              I have used SS screws after clamping to hold the 2 layers of plywood together after clamping, do not let the screws go all the way through and use flat head screws, not pan head.

              P/C Pete has good info

              If you need more info contact me on BOC I will also watch the thread. boatworkfl
              Pat says: DO-IT-RIGHT THE FIRST TIME!

              Bayliner 3870 "ALASKA33)
              Twin 350 GM power
              Located in Seward, AK
              Retired marine surveyor

              Comment


                #8
                All good info, but you should check Transom And Stringers by drilling at least a 1/4" holes to check for moisture and more importantly rot. I have the same vintage boat as yours and found wet transom/stringers but a small amount of rot at the drain only. Transoms and stringers can be dried, Im on my third shop vac. It takes time but I rebuilt the transom and stringers on a 19' which took a lot more time and dollars.

                Learn what it will take before you get started. Using Poly resin the surface needs to be clean and ground to make a good composite. If you decide to tackle it Clean the bilge and all surfaces with oil/ wax remover before you start well. I found on my 19" that the chop had sucked years of oil into the layup.
                North Puget Sound/Camano Island
                1985 2460 Trophy
                VP280/305 Changing to 280/DP-350

                Comment


                  #9
                  That is a very time consuming project. Not expensive material wise, not difficult skill wise, but lots of labor. Just know what you are getting into up front. If it’s a boat you like a lot and plan to keep, it’s worth doing if you like working with your hands. If it’s a boat you plan to sell, it’s not worth it, you won’t get your time or money back.
                  Esteban
                  B-ham!
                  Former Bayliners 3218, 2859, 2252, 1952

                  Comment


                    #10
                    It could also be a leaking transom shield, assuming its an I/O and not an outboard.

                    good luck
                    Ron
                    1989 3218
                    1988 Boston Whaler 13 Super Sport Limited
                    2007 Yamaha VX Cruiser

                    Comment


                      #11
                      Use epoxy resin or at min vinylester resin. Much better strength wise and adheres to the original poly resin better than poly does to itself. Plus its waterproof poly is not fully waterproof. If you do it, check that the outside surface of the transom where the transom shield attaches for flatness. My 2859 was not flat and was leaking past the seal all around the bottom. Took some work sanding and checking with a flat edge to get it right. The transom shield would "rock" top to bottom because of a high spot about midway up the keyhole. The top of the shield was tight against the transom and around the bottom was a slight gap not tightly sealed.

                      just my experience. Something to check
                      Doug
                      1995 496cu in. 2859 Bravo ll
                      The Doghouse
                      Prince George BC

                      Comment


                        #12
                        Originally posted by sketch96 View Post
                        Use epoxy resin or at min vinylester resin. Much better strength wise and adheres to the original poly resin better than poly does to itself. Plus its waterproof poly is not fully waterproof. If you do it, check that the outside surface of the transom where the transom shield attaches for flatness. My 2859 was not flat and was leaking past the seal all around the bottom. Took some work sanding and checking with a flat edge to get it right. The transom shield would "rock" top to bottom because of a high spot about midway up the keyhole. The top of the shield was tight against the transom and around the bottom was a slight gap not tightly sealed.

                        just my experience. Something to check
                        Yes, per Mercruiser installation spec, the area around the "key hole" needs to be flat within a 1/16th. I'd also go epoxy.
                        Dave
                        Edmonds, WA
                        "THE FIX"
                        '93 2556 5.7 Bravo II 2.0:1 18 1/4x19 P
                        (.030 over-Vortec top end-part closed cooled)
                        The rebuild of my 2556 https://www.baylinerownersclub.org/f...76?view=thread
                        Misc. projects thread
                        https://www.baylinerownersclub.org/f...56-gctid789773

                        Comment


                          #13
                          ISO type resin is waterproof and is less expensive, besides your will be gel coating both the exterior and interior & sealing any penetrations such as the outdrive hole.
                          If you use epoxy you will need to paint it as gel coat will not stick to epoxy very well.
                          You can epoxy the 2 layers of plywood together though.
                          Pat says: DO-IT-RIGHT THE FIRST TIME!

                          Bayliner 3870 "ALASKA33)
                          Twin 350 GM power
                          Located in Seward, AK
                          Retired marine surveyor

                          Comment


                            #14
                            The Gelcoat over epoxy thing is debatable, it has been done by members on this site and others have had success with the proceedure. A coat of polyester/vinelester resin applied to the epoxy while tacky followed by Gelcoat seems to be the preferred method. But I agree you'll not achieve the chemical bond between the two, however when replacing a transom in an "old boat" the bond will be mechanical regardless of the type of resin used and epoxy on its own is far stronger. Yes?
                            Dave
                            Edmonds, WA
                            "THE FIX"
                            '93 2556 5.7 Bravo II 2.0:1 18 1/4x19 P
                            (.030 over-Vortec top end-part closed cooled)
                            The rebuild of my 2556 https://www.baylinerownersclub.org/f...76?view=thread
                            Misc. projects thread
                            https://www.baylinerownersclub.org/f...56-gctid789773

                            Comment


                              #15
                              Originally posted by builderdude View Post
                              The Gelcoat over epoxy thing is debatable, it has been done by members on this site and others have had success with the proceedure. A coat of polyester/vinelester resin applied to the epoxy while tacky followed by Gelcoat seems to be the preferred method. But I agree you'll not achieve the chemical bond between the two, however when replacing a transom in an "old boat" the bond will be mechanical regardless of the type of resin used and epoxy on its own is far stronger. Yes?
                              It is called over kill. With my business discount I paid $63.00 for a gallon of V/E resin, I pay $183.00 for 5 gal of iso resin, epoxy is even more costly and harder for the layman to use.
                              Pat says: DO-IT-RIGHT THE FIRST TIME!

                              Bayliner 3870 "ALASKA33)
                              Twin 350 GM power
                              Located in Seward, AK
                              Retired marine surveyor

                              Comment

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