New Member and Project Intro **Texas Scooter**

Discussion in 'Boat Design' started by PPRINT, Dec 24, 2016.

  1. PPRINT
    Joined: Dec 2016
    Posts: 14
    Likes: 2, Points: 3, Legacy Rep: 10
    Location: Texas, USA

    PPRINT RobT

    Hello all, I am a new member here and figured I would start an introduction of myself and the project that I am currently contemplating.

    Me:
    My name is Rob and I live in the South Central Texas area. I have never built a complete boat from scratch, but have modified my Mod V aluminum hull boat extensively. I certainly understand that modifying a boat does not qualify me as a builder, but is does provide me a little insight into how they are built and the mistakes that are easily made when not enough planning has been performed. That's a whole other story I won't get into. LOL.
    The bay I normally fish is shallow (1-4ft) for the most part, and the really good fishing is in areas with less than a foot of water. I can get close to those locations with my current vessel, but have to lift the engine and push pole into the back lakes. You can imagine how sore a middle aged man can get after a few days of poling around for 8 hours/day. I have researched the boats used for this style of fishing and have decided I want a “Scooter” boat. This style of boat will typically float in less that 6” of water and run in just shy of half that amount over mud.

    My project:
    I am looking to build a 10' version of the historical “Texas Scooter” with 24” sponsons integrated into the hull design. Not sure if that means I am making a 10' boat or a 12' boat, but the transom is 10' from the front edge of the bow. The width will be approximately 72” wide for stability. I have already purchased a used 40hp 2stroke engine with all the rigging, so I'm set for propulsion. FYI, the engine I have weighs 185lbs minus rigging. This will be what I consider a “wet” hull in that it will be water tight and will be capable of taking waves with the water running off the back of the boat. There will not be any openings or piercings into the hull. All rigging will be on top of the deck and the console will be mounted to blocks that are epoxied to the top of the finished gel coated hull.

    After spending a fair amount of time investigating the hulls currently on the market, I have modeled several versions of what I am thinking about. You will find a few drawings attached that show the latest revision, but by no means are they completely thought out. Just roughed in for basic budgetary work and weight calculations.

    Just for general knowledge, I have investigated buying a new rigged version of what I want ($14K+ cold molded in fiberglass), buying a well used hull, or complete boat ($2500-$4500)and scraping it out and rebuilding it from the stringers on up($1000-$2000), or having my latest drawing revision quoted fabricated in aluminum by a professional boat fabrication company. I submitted the RFQ for the aluminum hull but have not received the quote yet. I am guessing anywhere from $5K-9K for a raw aluminum hull.

    My final option is what has me here introducing myself...building it from scratch as either plywood/fiberglass or foam/fiberglass.

    I am currently trying to decide if I want to use 1/4” marine ply and building the core as a matrix of stringers and bulkheads on 16” centers, or go with less, but thicker ply and use battens similar to the current Glen-L building method on their 16' Scooter designs. One of the drawings attached shows a rough cut of the matrix I am considering. All of the components of that design will be cut on a CNC router by a cabinet maker friend of mine.

    After reading this forum for a few weeks I am confident that I am in the right place for advice on this project. I would love to hear critiques and comments to help stimulate more conversation on this boat design.

    Sincerely,
    Rob
     

    Attached Files:

  2. TANSL
    Joined: Sep 2011
    Posts: 5,855
    Likes: 215, Points: 73, Legacy Rep: 300
    Location: Spain

    TANSL Senior Member

    Need to put drain holes at every floor and girder.
    Assuming that it is a metallic structure, you should properly calculate the welds and their sequence to avoid deformations on the parts so thin. How do you weld the sole to bottom floors and longitudinal girders?
     
  3. upchurchmr
    Joined: Feb 2011
    Posts: 2,875
    Likes: 89, Points: 48, Legacy Rep: 579
    Location: Ft. Worth, Tx, USA

    upchurchmr Senior Member

    Tansl - he said plywood pretty clearly.
     
  4. PPRINT
    Joined: Dec 2016
    Posts: 14
    Likes: 2, Points: 3, Legacy Rep: 10
    Location: Texas, USA

    PPRINT RobT

    TANSL...I did mix two different build methods in the description and I can see how that can be confusing.

    If I were to go with an aluminum version I would leave the interior features up to the fabricator. Have to make them work for their money. Even though aluminum is my preferred material for a boat, I am certain the cost would exceed my wife's comfort level on what I sold her as a cost effective second boat option.

    The discussions I am hoping to spark here is concerning the ply or foam version....which I am certain will better fit my budget. Not to mention I have something inside me that drives me to build anything I can rather than paying someone to do it. I have my limits, but that has never stopped me from jumping in with both feet.

    Thanks for the comments.
    Rob
     
  5. TANSL
    Joined: Sep 2011
    Posts: 5,855
    Likes: 215, Points: 73, Legacy Rep: 300
    Location: Spain

    TANSL Senior Member

    You're very right. A thousand apologies for my clumsiness. I have to read the posts more carefully. In my opinion, for this type of boat, the right material is aluminum and I stopped reading OP's text before I finished it.
    (Don´t forget drain holes)
     
  6. PAR
    Joined: Nov 2003
    Posts: 19,133
    Likes: 473, Points: 93, Legacy Rep: 3967
    Location: Eustis, FL

    PAR Yacht Designer/Builder

    Have you done a more comprehensive weight study, as 10' is awful short to hold up you, a beer cooler, the 250 pounds of fuel, controls and engine, etc., even with a 6' beam. You've lost a fair bit of the plane patch to the tunnel and transom cutout, further reducing this little puppy's capacity.

    I also question some of your scantlings, given the performance potential of this. As speeds increase the loading and load paths rise exponentially and this isn't easy for the novice to calculate without some experience.
     
  7. PPRINT
    Joined: Dec 2016
    Posts: 14
    Likes: 2, Points: 3, Legacy Rep: 10
    Location: Texas, USA

    PPRINT RobT

    PAR, those are exactly the types of questions I want. Keep in mind I do not know much about the construction of vessels, so I am learning as I go. I even had to google "scantling"...LOL. Boat building has a language all its own it appears.

    The weight study.
    I sectioned my existing model in 1/2" increments and measured the volume. I built a spread sheet to calculate the weight displacement at various draft depths. I hope that is the way it is done. I have attached a screen capture of the spreadsheet calcs below. I'll start gathering actual weights for the rigging and such since I already have it.

    While I can calculate the hull weight of the dry plywood fairly accurately, I do not have any data on how heavy the same panels are once they have been encapsulated and the exterior fiber glassed. Any data on this front would be greatly appreciated.

    I am hoping I am fairly safe with my current design given there are numerous versions of this hull on the market today. Just outside of what I want to spend for them. You can see the MOWDY S10 is nearly identical to my design with the exception of the casting deck on my design.

    Here is a youtube video of the MOWDY in action.

    https://www.youtube.com/watch?v=mUkWgqWRMF0

    Edit:
    I'm bored waiting on Santa so I ran out to the shop and weighed everything. Screen capture added below.

    If my methodology is correct, and my guess at hull weight is in the ball park...the boat ready to fish should float about 4.5".
     

    Attached Files:


  8. SamSam
    Joined: Feb 2005
    Posts: 3,818
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    Location: Coastal Georgia

    SamSam Senior Member

    Someone on this site built a barge of plywood and fiberglass using that "matrix" method. I believe it was not anywhere as easy as he thought it would be and the guy wasn't happy.
    It wouldn't surprise me if it already has serious rot and it was only maybe 2 years ago he built it.
     
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