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  • Transom repir with Seacast

    Greetings from a newbie. I have a 1973 MAKO 17' Angler that I will start to restore this summer. I was always told that Mako had used treated wood in the transoms. But that does not seem to be the case as I read the post here. As I tend to over research all my repairs (read perfectionist) I recently found a product called "Seacast"

    www.transomrepair.com

    This is extremely interesting to me. I have not yet done a through check of my transom but this method has my interest.

    If I do not have to tear up the entire stern liner to get the wood out and am able to save, intact the inner & outer transom skin this sounds good to me.

    Now I want the collective cosmic knowledge of this site to feel free to weigh in on this product.

    Let the games/discussion begin
    Alabat - Cajun for \"Hey over there\"[br]1973 - 17 Mako Angler 115HP Suzuki[br]Houma, Louisiana[br]Home of the best Red fishing in the world

  • #2
    alabat,

    I also started on this discussion board, by asking this same question, regarding seacast.

    I did a BUNCH of exhaustive research on this product and finally chose NOT to use it based soley on calculated final weight. If your transom is not "overly" large, then a few pounds won't make much difference.

    For a given volume it is slightly more than double the weight of plywood.

    In my case I was already needing a diet, and would have had to make the transom even thicker, due to the extra Wt. & HP of the motor package I chose... So I finally settled Coosa board (approx 1/2 the wieght of plywood).

    From my research, what I can add is for me THE reason to pouring the transom with seacast seems to be the ease of installation. I still wish it did not weigh so much, because I'd already be done and back on the water, rather than still working on it...

    Hope this helps... Good luck, OB1
    Working for a livin\' is HIGHLY Over-Rated...[][br]

    Comment


    • #3
      Welcome Aboard alabat. I see your in Ringleaders back yard.

      The wood core has to be removed to use that stuff. That mean's one tool will do it best. "Chainsaw" Yes a chainsaw is used to get down between the inner and outer skin's to remove the core.

      Now here's where I have a problem with this stuff.

      There is no way to grind the inside of the skin's after the core is removed. So how well is this stuff going to stick to the skin's?

      It would lead to delamination. I have no personal experance with this stuff, other than a few samples laying in front of me here.

      Comment


      • #4
        Here are some threads on SeaCast:

        http://www.classicmako.com/forum/top...hTerms=seacast

        http://www.classicmako.com/forum/top...hTerms=seacast

        You can do a search to find more discussion.
        [br]***[br]\'82 Ski Nautique - Lake Martin, AL[br]\'80 236IB - Lake Martin, AL[br]\'03 Pursuit 2670 - Destin, FL

        Comment


        • #5
          Many Thanks DestinBound. That was a interesting thread on Seacast, seems like there is a lot of misinformation as to its weight and if it works. But if he is able to stay in business and keeps selling it I would say it probabily works. We all have our favorite methods of rebuilding boats and you have to be comfortable with it cause when you get offshore it's your life on the line.

          As to the weight issue, as you pointed out, it does not seem to be a big deal. And as to what happens five years down the road the same could be said for any other method.

          Thnaks again for the links
          Alabat - Cajun for \"Hey over there\"[br]1973 - 17 Mako Angler 115HP Suzuki[br]Houma, Louisiana[br]Home of the best Red fishing in the world

          Comment


          • #6
            ablat,

            If you are concerned with de-lamination, then following "chainsaw surgery" (BTW, I did "chainsaw surgery" to remove my transom core wood, as I found it to be THE easiest means of removing the wood.) Just don't forece the saw, let it do the work, so you don't eat too many holes in the fiberglass...

            Anyway, once the lions share of the wood is out, then mark and then carefully cut the outer transom skin off, using a 4" die-grinder type cutoff wheel in your 4" grinder.

            Then you can lay the removed outer down flat, and grind the "bejesus" out of it to get ALL of the wood off, and this will also give you room to work on the inner.

            Following that, simply re-install the outer (using proper glass repair joint methods), then pour the transom. If done this way I would have to believe the chances of it de-laminating from the seacast would be NIL.

            WITH ANY METHOD of transom core replacement, THE TRICK is to COMPLETELY clean both of the skins (wash them down with some acetone as well). It flat out doesn't matter if you're pouring your transom or not, these surfaces HAVE to be clean for them to adhere to anything new you install...

            Again, my ONLY reason for not using it was the weight caused by the physical size of my transom, and the additional thickness I needed due to my powerplant package, making it's calculated weight a tad over 145 lbs more than doing the same job with plywood. I save approx. 80 lbs over plywood, by using Coosa. I simply could not accept the 200(+) lbs difference between Coosa & Seacast.

            Hope this helps clarify some of the things about the task you're undertaking...

            Good Luck, OB1...
            Working for a livin\' is HIGHLY Over-Rated...[][br]

            Comment


            • #7
              just butting in here, but your comment about 5 years life span for

              a transom repair done following the recommendations found here?

              You must mean 5 decades

              Mark
              \'73 22 Mako Reedville, VA

              Comment


              • #8
                The comment about the five year life span was from the links that I read given to me by DestinBound and were not my opinion.

                But I have to wonder about all the concerns over the weight of the rebuilt transom. I am concerned about the weight because of the shallow marsh in south Louisiana where I fish. So I balance the boat out as much as possible by moving weight around. Mainly putting the batteries in the console and the ice chest forward. I am not a big fan of four strokes because of the weight issue versus a 2 stroke. My DT115 Suzuki weighs all of 360-375.

                If I have to rebuild the transom I will be more concerned about total strength of the rebuild. In my opinion the last way I would ever rebuild a transom is to cut out the back/outside of it. In my opinion a transom is best rebuilt from the inside.

                I have to go now but will elaborate more latter.

                In the mean time for some excellent professional advice go ot

                www.yachtsurvey.com

                David Pascoe is a marine survey and makes some excellent points. Also read his write up on how to reinstall a gas tank before you have to do it.

                Last shot - We are all our own Captain's and have to do what we are the most comfortable with after reviewing all the facts. It is not the route we take it's did we get there.
                Alabat - Cajun for \"Hey over there\"[br]1973 - 17 Mako Angler 115HP Suzuki[br]Houma, Louisiana[br]Home of the best Red fishing in the world

                Comment


                • #9
                  quote:


                  Originally posted by alabat


                  But I have to wonder about all the concerns over the weight of the rebuilt transom. I am concerned about the weight because of the shallow marsh in south Louisiana where I fish. So I balance the boat out as much as possible by moving weight around. Mainly putting the batteries in the console and the ice chest forward. I am not a big fan of four strokes because of the weight issue versus a 2 stroke. My DT115 Suzuki weighs all of 360-375.


                  If I have to rebuild the transom I will be more concerned about total strength of the rebuild. In my opinion the last way I would ever rebuild a transom is to cut out the back/outside of it. In my opinion a transom is best rebuilt from the inside.

                  I have to go now but will elaborate more latter.

                  In the mean time for some excellent professional advice go ot

                  www.yachtsurvey.com

                  David Pascoe is a marine survey and makes some excellent points. Also read his write up on how to reinstall a gas tank before you have to do it.

                  Last shot - We are all our own Captain's and have to do what we are the most comfortable with after reviewing all the facts.



                  alabat

                  You are indeed your own captian and should decide what & how to do what you are comfortable with. You will certianly be living with the decision(s).

                  But if I may, perhaps some additional information would be helpful in making your decision based on the facts of your particular boat and situation.

                  Weight issue(s)...

                  1- 2001 & newer DF115's weigh 416 lbs, (my 2004 DF140's weigh 410 each).

                  2- WEIGHT of Seacast -VS- Marine grade plywood as transom core material.

                  Perhaps the simplest way to figure the weights is to do so by measuring your transom, then calculating the volume of the core material for your particular boat.

                  To do this, you need to measure the physical size (surface area) of your transom. Do it at the outer skin for simplicity... You will need to measure; (total height, total width, the deadrise - AND of course any significant cutouts for motors, or any significant "slanting of the gunwales, etc.). Don't get caught up in measuring to the nearest 1/8th inch. The closet 1/2" (or even closest inch) will be plenty close enough for the purpose of getting comparisons.

                  Next, multiply the area of your transom times the CORE thickness (this SHOULD be to the nearest 1/8th inch), and if you've measured all the above in inches, you will get the transom core volume in cubic inches.

                  SEACAST VOLUME

                  Next, divide the transoms calculated cubic inch volume, by 231 (there are 231 cubic inches per gallon of liquid material) to get the number of gallons of "pourable material" (IE: Seacast) that you will need to refill the volume left by the removed wood.

                  It should then be a simple calculation to figure what the core will weigh when you're done, based on the amount of material you will need to order/pour. I'll let the folks at seacast give you thier latest volume/weight figures.

                  PLYWOOD VOLUME/WEIGHT

                  Calculating the weight for the plywood core is pretty simple as the "industry average" for marine grade pine plywoods, works out to be approx. 0.022 lbs/cu inch.

                  Example(s);

                  A- 100 cubic inches of core plywood will weigh approx 2.2 lbs. (100 x 0.022 = 2.2).

                  B- One "gallon-volume" of marine grade plywood (IE: 231 cu in) will weigh approx 5 lbs (231 x x0.022 = 5.08)

                  STRENGTH ISSUES

                  3- Removing the inner skin may at first appear to be less work, and resulting in greater strength, (perhaps some folks would think that based on fear of making a mess of the visible outer surface ?), but the outer skin removal is significantly simpler than removing the inner liner and inner transom skin to access the core material.

                  A- In removing the outer, you can stand outside the boat, on the ground and work standing up, rather than tring to do it on you knees or partially sitting and hunched over.

                  B- In removing the outer, there are no unusual surfaces or angles to match up when you put it back on... IE: ALL of the surfaces you will be working with when you are re-fitting and finishing are flat, thus EASY yo get to come out right visually... AND you only have to paint the outer surfaces, when you're done.

                  C- Finally, a properly done joint, should be every bit as strong as the original material was.

                  HOWEVER... Whether you decide to remove the inner -OR- the outer, either way you do decide to do it, can result in sufficient (and similar) strength, as long as you follow proper lamination and joint procedures, and keep ALL of the bonded surfaces squeaky clean. (true for either method you choose).

                  I'm only hoping to provide factual information of the materials and the work which lie ahead. I hope this information helps.

                  Good Luck... and let me know if I can help in any way...

                  PS: Would be happy to help ANY of the folks on this forum with performing [8)]calculations etc...[][][]
                  Working for a livin\' is HIGHLY Over-Rated...[][br]

                  Comment


                  • #10
                    Alabat - David Pascoe's wbsite is awesome, I hope (assume?) everyone here has read ALL OF IT. I have. Read the gas tank installion section. Write-ups of various models are choice....AGAIN, if you re-do your Mako transom along the lines recommended here on classicmako.com, 5 years is 20 years too few. This is solid stuff. No one here wants to be re-doing their transom in 5, or even 10 years. (Or EVER?). That's why do it right now. Of course, proper preparation is the key......can't laminate on top of dirt or dust, can you?

                    My .02

                    Mark
                    \'73 22 Mako Reedville, VA

                    Comment


                    • #11
                      A couple of note's here:

                      Marine Plywood is Fir plywood, unless you get into Meranti or Okume.

                      I've never seen Pine plywood marketed as Marine. Pine is heavyer. Preasure Treated plywood doesn't count, but that's what they will try to sell you at HD or Lowes.

                      Fuel tank's and Dave Pascoe's methiod.

                      Sound's good on paper, but there's no air flow under a Mako deck. Therefore the use of Coal Tar epoxy is the prefered method and foamed in.

                      Comment


                      • #12
                        Two years ago I replaced my Grady's central fuel tank, and re-cored the deckplate over it. Regardless of how new, well fiberglassed and "rot proof" all surfaces are, I still leave deckplates and hatches open on nice warm days and over the winter. I think that helps to keep moisture and condensation at bay.

                        I used Nidyia Core for the deckplate, and it worked our surprisingly well. I my Sportcraft's main deckplate (which was also recored) I used some 3/4 Home Depot Plywood I had laying around. I coated it VERY LIBERALLY with Polyester Resin and placed two layers of mat over it. When time comes to screw it into place all screw holes will be filled with 3M Marine Sealant. I think that as long as the ply is kept dry I shoulden't have any problems.

                        Marine Ply from what I understand is also much stronger then it's plywood counterpart. Is this true?
                        Jones Inlet, Long Island

                        Comment


                        • #13
                          quote:


                          Marine Ply from what I understand is also much stronger then it's plywood counterpart. Is this true?



                          Yes it is. This is due to more ply's and "0" voids.

                          Where it really shin's is if you need to bend it.

                          This would be where you are building a hull and you had to torture the plywood into submission to conform correctly.

                          Comment


                          • #14
                            Reply to Pascoe's fuel tank install.. it's been a while since I read it, and yeah he's a big boat guy mostly. I learned a ton from his website, though.

                            Mark
                            \'73 22 Mako Reedville, VA

                            Comment


                            • #15
                              alabat,

                              Warthog correctly identified a "semi-gaff" in my post. MOST North American manufactured marine plywoods are NOT Pine as I had said in my previous post, but is instead typically either made from fir or western larch.

                              In either event, the weight density of a properly treated plywood made from either; Pine, Fir, or Western Larch, is so close that the weight numbers per cubic inch provided, are still valid.

                              Good Luck...
                              Working for a livin\' is HIGHLY Over-Rated...[][br]

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