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My Take on a scratch built Gato sub

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  • My Take on a scratch built Gato sub

    This is what I spent my spare polyester resin on two years ago..Scale 1/64-.was gas (freon134) operated with central ballast tank...converted it to water ballast fore and aft tanks last winter...what a difference...great control, water doesn't slosh anymore in tank when sub is not level (I even tried baffles of many designs) If you've noticed the water tight compartments might look familiar...Why reinvent the wheel! I realized that there were many watertight containers out there in the supermarket ready to be repurposed . They work great! just mount everything on a platform and attach it to the open, just hold the lid and turn the jar need to disconnect any wires (they stay with the lid) to make any adjustments or changes. No fancy high tech plexy tubes and o-rings..keep it simple. I also realized that you dont need to put everything in a watertight compartment. I used a waterproof proboat esc and it sits in the wet part of the hull as does the steering and dive planes servos-hitec waterproof servos..frees up alot of valuable dry real estate ...especially in a hull thats only 3 inches wide !

    To minimize wire connections I bussed together the ground and the power wires to the servos (all the reds together to one wire and all the blacks together to another wire)-this eliminated a bunch of thru wtc fittings and possible leaks.

    I also took the wires going from one wtc module to another and ran them inside tygon tubing. This did two things , it kept these wires out of the water and it supplied air to and from these modules. You see I used these modules for additional air accumulation. If I just pumped water into an empty ballast tank, they say I could only utilize about 80% of the volume..but this way I utilize 80% of the combined volume of all wtc and the ballast tanks together. And! the positive pressure in the wtc s keeps out any water should a leak arise.

    The deck was made from fiberglass with bass wood strips applied. To do the fiberglass I take a sheet of parchment paper on a flat surface and lay up several layers (in this case it was 3) and apply a layer of parchment paper over the top. Squeegee excess resin out to the sides but still under the paper-it's much less messy- with a credit card and lay something flat on top till set. Then I drew the deck segments out on the flat sheet cut out and proceeded to drill 1/8 in holes to completely perforate the fiberglass. Now with the bass wood applied with its spacing all air passes right thru the decking -none trapped, works great!

    It took me a while to figure out the weld seams on the hull...then it hit me. It's a little messy but that's what acetone is for. I took a strong shiny Thread of the appropriate diameter (upholstery thread) and worked it thru with epoxy using my fingers. Then applied the wet threads to the hull where needed...instant seams..

    I used the encapsulated reed switch from a household door alarm switch for my radio on/off its waterproof.. just have to put magnet ,in my case, to turn off battery near the spot on deck where the switch is.

    Need ballast weight..don't mess with lead shot or wheel weights or lead fishing sinkers its expensive. I used some well placed rebar- just clean it up to bare metal and paint with epoxy/epoxy paint ,silicon rubber holds it in nicely.
    Last edited by Bob Gato; 03-09-2019, 06:16 AM.

  • #2


    • #3
      Nicely done! Typically when you hear someone say they scratchbuilt their model, it ends up looking like a lumpy log with a cap on top, but your model looks awesome.


      • #4
        Thanks -my fingers still hurt whenever I think of filing all those flood holes! and those guns..two weeks to build!

        I'd like to upgrade my radio-the old Skyport 6 is on it's last legs-maybe 75MHZ.
        Last edited by Bob Gato; 03-09-2019, 09:02 AM.


        • #5
          I've got a package I offer with VEX 6-channel computerized radio, 75mhz 6-channel receiver and matching crystal set for $143 plus shipping.


          • #6
            Really! I'll check it out..I am deep into building a 1/24 Mark V spec ops boat and the sub is next on list at the boatyard for the spring..


            • #7
              That is some spectacular work, Bob. Looks fresh off the slipway and ready for war.
              Dead men tell no tales...


              • #8
                Thanks-I just had to learn how to drive-maiden voyage since converting from single gas ballast to fore and aft pump ballast..


                • #9
                  I have to admit Bob, you're taking all this like "a sub to water".

                  I'm coming to YOU now for hints!

                  VERY happy you're actively posting. Wish I could get the rest of them as active.
                  v/r "Sub" Ed

                  Silent Service "Cold War" Veteran (The good years!)
                  NEVER underestimate the power of a Sailor who served aboard a submarine.