1968 Glastron resto pics; flimsy sides need support ideas!

Discussion in 'Boatbuilding' started by mike_ct, Dec 16, 2009.

  1. mike_ct
    Joined: Dec 2009
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    Location: Southington, CT

    mike_ct New Member

    Hi all..started working on a 1968 Glastron, needs the usual once over, transom+deck, and interior..boat was given to me by friend, his grandfather (deceased) was original owner..i'd like to get it together over the winter, and get his grandma out for a ride before her health gets the best of her..sat outside uncovered for probably 8-10 years, so assume the worst..good news is, the 50hp merc spins over and has comp, steering stuff is intact and can at least be copied, and the cap looks good, albiet very faded, trailer is structurally excellent, and i did the bearings, hubs, wheels, and tires, needs paint..

    reason i'm here, is to get some ideas! I'm not new to boats, although this is my first transom, but thats not what i'm here for..i realize with the cap off the sides are going to be flimsy, but i would really like to do something here..i also know newer boats are finished much nicer regarding the areas of the sides, and i know some little plywood word with cubby holes cutout fixed to the cap rim and the bottom of the hull will sure add some strength...i've also seen pictures of glastrons with some funky seats that not only fix to the deck, but also fix to the cap and possibly the sides, kind of tieing everything together..what are my options with my main goals being

    1) strengthen and limit the flimsyness of the sides
    2) strengthen the cap (it its current installed state before disassembly it was flimsy up and down, like you have to be careful climbing in and out of the boat to not put weight on it

    some pics..excuse the crappy photoshop work, trying to highlight some areas..not sure if they are where I should be looking..I wanted to add some triangles from the transom to stringers to help support the motor weight/flex (I've seen this design used on newer boats this size) and I feel like I need something on the sides, they flex lots, the cap helps a little, but i think the cap needs some plywood on the flat "gunnels" area like where it attaches to the sides, where you put your arms, legs, etc when climbing in and out of the boat..i just to build it right so its good and strong, and slightly more of a modern design in terms of structure (newer boats are just solid as a rock in these areas) and I just want to copy what they do.
     

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  2. masalai
    Joined: Oct 2007
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    Location: cruising, Australia

    masalai masalai

    I feel the essence may be to keep weight down so manufacturing some U shaped sections to place along the thwart ship sides (is thwart the right word?) and then glass that in place using glass tape... Stress your U shaped section by applying pressure to deform it slightly so it fits along the straighter parts of the sides by using clamps whilst fixing in place... Wiser and more experienced folk may offer better ideas...

    The rear (transom) in dubious mental recall, has usually been of plywood, glassed into place to withstand the rigours of a heavy outboard... Have fun and do yourself proud with your resto project... Be weary of the bracket as that may not be the best or most appropriate solution as the load spread to the sides and the bottom may best be effected with a stiff transom with enough thickness to take the outboard clamps/bolts and be that thickness full size of the transom...

    Just another amateur amateur throwing in 2 cents of ideas/thoughts...
     
  3. PAR
    Joined: Nov 2003
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    Location: Eustis, FL

    PAR Yacht Designer/Builder

    The sides of your boat are supposed to be "floppy". This is the nature of 'glass and why you see it molded into all sorts of shapes. These shapes offer "triangulation" which supports itself far better then relatively flat panels of 'glass.

    Forget the transom knee, install a splash well which will box beam the aft end of the boat. The splash well serves to hide the controls (steering, throttle, shift and electrical) to the outboard and most importantly offer a place where boarding water can enter, then leave without actually getting into the boat. Look at other boat and get ideas for layout. On each side of this well you can let the battery(s) and fuel tank(s) live.

    The sides of the boat could use some boxes to sit on (built in furniture), maybe a helm station too.

    Build the vast majority of this structure from 1/4" plywood, unless you butt will actually sit on it, then use 3/8" or 1/2". 1/4" is actually fine, but most feel better with more meat under their butt (flex).

    Do NOT be tempted to use 1/2" or thicker on everything. You'll just burden the boat with weight, which is a small craft killer, make the boat cost more and limit shape options (1/4" can bend nicely, but 1/2" doesn't very well).

    Of course you'll use fillets and taped joints on all structural pieces and fillets only on everything else. Fillets should 3 times as tall as the plywood is thick and taped joints 6 times as tall or better on both sides of the joint.

    Epoxy would be the resin choice for ease on the novice. Enjoy . . .
     
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  4. mike_ct
    Joined: Dec 2009
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    Location: Southington, CT

    mike_ct New Member

    thanks for the input and the tips! i'll be sure to keep progress updated as i go along..i do like the idea of boxing in the aft and 'triangles' for adding strength..is this the type of splash well i should be playing with? basically boxing the upper area of the transom with the sides of the boat and do away with the square boxes i have in each corner now?

    [​IMG]

    or something like this other mockup?
    http://www.boatdesign.net/forums/attachment.php?attachmentid=38330&stc=1&d=1261024763

    pardon the wildlife - http://www.boatdesign.net/forums/attachment.php?attachmentid=38331&stc=1&d=1261025020 - the cap has a small splash well (not structural to the transom). if i add something like the other pics show (in plywood) would i just do so under what i have already or try to make it all one piece bonded together?
     

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  5. PAR
    Joined: Nov 2003
    Posts: 19,133
    Likes: 476, Points: 93, Legacy Rep: 3967
    Location: Eustis, FL

    PAR Yacht Designer/Builder

    The first picture with the angled splash well doesn't have enough room for the various controls, etc. The engine wouldn't likely tit all the way up either. Also this angled piece and it's brackets seems to be made from plywood that's way too heavy for the job (appears to be 3/4"). I can't tell you how many boats have been ruined from over building them unnecessarily. It doesn't make them stronger, it actually makes them weaker if you do this.

    The image with the holes in the splash well is the scale of plywood you should be using, nothing thicker, except as transom replacement or seat tops. Though this arrangement looks to serve a special purpose, the thickness of the plywood is correct. You can also see the fillets, which should be slightly taller, though the tabbing of the sole to the hull shell looks good.

    It looks like you may have some foam or something under the aft portions of the side decks. It may be water/fuel soaked so you might want to cut it out (it's easy) and toss it. In fact the first order of business would be to empty the boat and clean it well. All that crap in there is just trapping moisture against things that don't like it.
     
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