37" TFL Genesis single motor SAW build

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  • fweasel
    master of some
    • Jul 2016
    • 4286

    #1

    37" TFL Genesis single motor SAW build

    I found a deal too good to pass up on a 37" fiberglass Genesis that had only been run 3 times. I was looking for a boat to build up for a close friend of mine to run with us next summer at the Mini Shootout and this will fit in nicely. I'm not decided yet on the electronics, depends on the class it will run. Could be stock (2000kV on 6S), or a modified motor and 5S or less for one class, 6S or more for the other. The bigger issue is that it will be driven by a complete novice and the water conditions a rarely glass like. So, reinforcement is the name of the game!

    First up, 30g of finishing resin and chopped carbon fiber poured into each sponson tip and a third pour over the bridge between the two. Propped the hull up in a bath of cold water because of the heat that the epoxy creates while curing.

    2018-02-18 12.38.02.jpg
    Vac-U-Tug Jr (13mph)
  • fweasel
    master of some
    • Jul 2016
    • 4286

    #2
    A lot of people run a dual cooling rudder on this boat, including the previous owner. Good idea for sport running, but the rudder blade is fat and bulky, and will create too much drag for my needs. I'll replace it with a thinner, shorter rudder and get my water from through hull pick-ups. Traced out templates for each pick-up on the bottom of the hull. Drilled out the four corners with a small dremel drill bit. Cut the long sides with a dremel cut-ff wheel and the short sides with a diamond grinder tip. Messaged the opening with a small file until the pick-ups just snapped into place. I had to thin out some fiberglass material near the corner of the sponson where the layup was too thick on the inside of the hull so that the pick-ups could sit perfectly flat. I taped them into place from the outside of the hull to seal off the cracks and prevent epoxy from leaking out. I locked them into place with a small pour of 30-minute epoxy over each pick-up and did a light sanding from the bottom side. A little epoxy leaked out and the cardboard I used to keep the pick-ups flush with the bottom of the hull got glues to the hull. I'll sand the rest of that off when I blueprint the pads later.

    2018-02-19 18.21.56.jpg 2018-02-19 18.22.38.jpg 2018-02-19 18.46.38.jpg 2018-02-19 19.00.27.jpg2018-02-24 21.07.38.jpg
    Vac-U-Tug Jr (13mph)

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    • fweasel
      master of some
      • Jul 2016
      • 4286

      #3
      Next up was the rudder/strut mount reinforcement. I've seen a number of build threads fill the transom from the inside with a large epoxy pour, directly over the mounting hardware, kfxguy and srislash in particular, so that's how I was going to do it. I replaced the stock mounting bolts with 6/32 stainless 1" coarse thread bolts and 6/32 blind nuts. The bolt pattern is pretty tight and the bottom two screws are very close to the floor, so I had to grind a flat spot into the two bottom nuts. I covered the bolt threads with anti-seize so the epoxy wouldn't stick, installed everything, and did my best to seal the holes from the outside with masking tape gasket between the mount and hull. Mixed up 60g of finishing resin and chopped carbon fiber, stood the hull up on its tail, and poured it in. I got decent coverage with the first pour, but the blind nuts weren't covered as well as I wanted, so I mixed up another 30g cup and poured it in. Set the hull in a bowl of cold water and let it cure overnight. In the morning I took it all apart, cleaned up the threads on the bolts, and did a little light wet sanding around the old rudder push rod hole that is now filled.

      2018-02-23 21.26.12.jpg 2018-02-23 22.06.21.jpg 2018-02-23 22.23.41.jpg 2018-02-23 22.25.07.jpg2018-02-23 22.47.42.jpg
      Vac-U-Tug Jr (13mph)

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      • fweasel
        master of some
        • Jul 2016
        • 4286

        #4
        The outside of the hull had a crown in two directions where the rudder and strut mount attached giving it very little surface area contact with the hull. I block sanded it as true as I could make it. Went clear through the gel coat, you can even see the seam run through the middle. I wasn't concerned because there was over a solid inch of epoxy and carbon fiber on the other side. It was still a little too low near the edges, so I masked off a rectangle and built up the sides with JB Weld. When that cures, I'll block sand it again and I should have a perfectly flat surface for the mount to butt up against.

        2018-02-24 10.26.13.jpg 2018-02-24 11.02.08.jpg
        Vac-U-Tug Jr (13mph)

        Comment

        • vinnyp
          Senior Member
          • Mar 2017
          • 283

          #5
          Ryan,
          Nice work. BUT, I nearly fell over when I saw your block sanding equipment. Alphabet and dinosaur blocks!!!

          By the way. if I EVER tried to put a boat in a tub of water on my wifes granite kitchen counter tops, it may be the last thing I do.

          Comment

          • fweasel
            master of some
            • Jul 2016
            • 4286

            #6
            I did say block sanding... They happened to stack at the exact height I needed to work at while keeping the hull flat on the counter. I do the cleaning in our kitchen so, I put bowls full of boats where I want them.
            Vac-U-Tug Jr (13mph)

            Comment

            • srislash
              Not there yet
              • Mar 2011
              • 7673

              #7
              That is a good system for the rudder standoff Ryan. Nice true and square. Excellent work so far. So are you going with deckkbraces/stringers then?

              Comment

              • Newboater
                Senior Member
                • Jul 2016
                • 359

                #8
                Very nice job, I do the bind nuts also, just a suggestion it is easier to turn the bind nuts around so the points stick out towards the front, this way you have them mount flat against the transome and the resin secures the tips. Also for the uneven rudder mount area you can skim coat with Marine rx to save on sanding. Look good 2000kv on 6s should haul. Really like the water pick ups.

                Comment

                • fweasel
                  master of some
                  • Jul 2016
                  • 4286

                  #9
                  Originally posted by srislash
                  That is a good system for the rudder standoff Ryan. Nice true and square. Excellent work so far. So are you going with deckkbraces/stringers then?
                  Yes, I'm going to install two stringers just like yours, after the inlay is done. The rudder standoff is dead true now.

                  2018-02-25 09.35.40.jpg


                  Originally posted by Newboater
                  Very nice job, I do the bind nuts also, just a suggestion it is easier to turn the bind nuts around so the points stick out towards the front, this way you have them mount flat against the transome and the resin secures the tips. Also for the uneven rudder mount area you can skim coat with Marine rx to save on sanding. Look good 2000kv on 6s should haul. Really like the water pick ups.
                  Thanks! That's a good idea on the blind nuts. I installed them at the ends of the bolts to put as much solid epoxy between the hull and nuts as possible since I decided not to use a transom doubler. Had there been room for carbon plate, I think it would have made more sense to use your reverse method. I had considered the Marin RX for several hull projects, but it's so damn expensive so I'm using what I have on hand. The JB Weld sands pretty easy and didn't take to long to true up.
                  Vac-U-Tug Jr (13mph)

                  Comment

                  • fweasel
                    master of some
                    • Jul 2016
                    • 4286

                    #10
                    2018-02-25 10.30.57.jpg 2018-02-25 10.46.46.jpg 2018-02-25 14.56.53.jpg
                    Ground out the epoxy line along the factory motor mount and popped that out. The battery trays put up quite a fight and took a fair amount of effort to cut into pieces and grind out the glued tabs. I sanded the entire interior to get things ready for the inlay. I also decided to fill in the gaps on either side of both stinger pockets under the rear deck. I built a dam with masking tape and poured in a thin epoxy mix until it was just about even with the tunnel. Now I can just lay the carbon inlay right over that area.

                    2018-02-25 14.01.11.jpg 2018-02-25 14.57.02.jpg
                    Had some carbon plate scraps left over so I traced out four corner tabs that I'll glue to the underside of the hatch opening to give me a place to install the hatch lock hardware. Haven't decided if I'll attach them before the inlay so the cloth can wrap right up to the edge, or after the inlay so I have more room to work. I don't think it really matters.
                    Vac-U-Tug Jr (13mph)

                    Comment

                    • kfxguy
                      Fast Electric Addict!
                      • Oct 2013
                      • 8746

                      #11
                      Nice job!
                      32" carbon rivercat single 4s 102mph, 27” mini Rivercat 92mph, kbb34 91mph, jessej micro cat(too fast) was

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                      • fweasel
                        master of some
                        • Jul 2016
                        • 4286

                        #12
                        Originally posted by kfxguy
                        Nice job!
                        Thanks. I'm going to hit you up for ideas on modifying the strut.
                        Vac-U-Tug Jr (13mph)

                        Comment

                        • kfxguy
                          Fast Electric Addict!
                          • Oct 2013
                          • 8746

                          #13
                          Originally posted by fweasel
                          Thanks. I'm going to hit you up for ideas on modifying the strut.
                          Anytime. I think this boat can go as fast as my buddy’s if setup right. I didn’t set his boat up to go that fast, it was supposed to be a 75-80mph boat tops on 6s but I think he ended up going like 88 and wanted more. He didn’t care what happened either because he’s got deep pockets.
                          32" carbon rivercat single 4s 102mph, 27” mini Rivercat 92mph, kbb34 91mph, jessej micro cat(too fast) was

                          Comment

                          • fweasel
                            master of some
                            • Jul 2016
                            • 4286

                            #14
                            I'd like to think I'm building it strong enough to do 100, but it will never see that because I don't plan on running that much voltage or motor. 80's would be good, plus, the boat is not for me, it's for a complete newbie to run at the shootout with us. He'd have just as much fun with a recoil26, but I have standards for my pit tables.
                            Vac-U-Tug Jr (13mph)

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                            • fweasel
                              master of some
                              • Jul 2016
                              • 4286

                              #15
                              Drew my inlay templates last night, cut out the carbon this morning, and laid it all in this afternoon. One layer across the majority of the hull and a second layer (put down first) along the side seams.

                              2018-03-03 15.26.48.jpg 2018-03-03 18.07.40.jpg 2018-03-03 18.07.59.jpg

                              I want to put a layer of fiberglass cloth on the rear deck so the GPS will still work back there and one layer of carbon under the front deck. Hopefully tomorrow on those.
                              Vac-U-Tug Jr (13mph)

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