`

Author Topic: plywood thickness for deck and bottom?  (Read 5468 times)

Gades

  • Waikiki Status
  • *
  • Posts: 24
    • View Profile
plywood thickness for deck and bottom?
« on: April 19, 2011, 05:19:11 AM »
hi there,
what thickness are you guys using, or what thickness would you use for a 11 footer?

I'd use plywood with one layer of fiberglass/epoxy around the whole board.

Cheers

TallDude

  • Cortez Bank Status
  • *****
  • Posts: 5669
  • Capistrano Beach
    • View Profile
    • Email
Re: plywood thickness for deck and bottom?
« Reply #1 on: April 19, 2011, 09:56:33 AM »
How durable do you want it? They make some canoes very thin, but the weight is distributed. For a SUP you will have a lot of force in one spot on the deck. the closer you make your frames (internal perpendicular supports) the thinner the plywood on the deck. If you think the board might be subject to hitting rocks, or seeing a shore break, then I would make the hull a little thicker as well. Each plywood is different in strength, given the same thickness. The strength depends on the type of wood, how it was cut, and how the grain is oriented on each layer of veneer that makes up the plywood. They are really a composite. You could put a layer of carbon fiber sandwiched between two layers of Sapele' veneer and you would have one very strong piece of plywood. you get the picture. When looking at plywood, get a tight marine grade ply in the 4 to 6mm (3/16" to 1/4"). Here is a link to were you can get it. http://www.noahsboatbuilding.com/noahusa/items.asp?Cc=TIAMAPLY&iTpStatus=0&Tp=&Bc=
It's not overhead to me!
8'8" L-41 ST and a whole pile of boards I rarely use.

JeffBach

  • Rincon Status
  • ***
  • Posts: 193
    • View Profile
    • Email
Re: plywood thickness for deck and bottom?
« Reply #2 on: April 19, 2011, 11:18:40 AM »
I used 4 mm plywood.  Can't remember the species.  Also the plans called for 3mm thickness of a different species which would have required selling one of my kids to afford buying, plus there was no local source for it.  So I did the thicker heavier, cheaper wood whose name I can't remember.......

So far I've not smacked anything with the hull.  Have dropped hard to my knees once on the deck with no apparent damage I could see or feel.

Initially I planned on building two boards.  So this first one I was considering as a learning experience.  But it went so well, I've not been too anxious for a second board.

As in the other thread, the biggest thing I learned was to be patient with scarf joints.  Mine are UGLY.  Functional but really ugly.  sand then fit then sand then fit.  when ready DO NOT USE TOO MUCH of the thickened resin paste stuff.  You don't need very much.  Any excess squirts out of the joint and hardens like a rock, which takes FOREVER to sand down.

Gades

  • Waikiki Status
  • *
  • Posts: 24
    • View Profile
Re: plywood thickness for deck and bottom?
« Reply #3 on: April 19, 2011, 02:01:01 PM »
I used 4 mm plywood.  Can't remember the species.  Also the plans called for 3mm thickness of a different species which would have required selling one of my kids to afford buying, plus there was no local source for it.  So I did the thicker heavier, cheaper wood whose name I can't remember.......

so, you've used a 4mm plywood sheet for the deck
and what else did you use? I assume some fiberglass with epoxy?

also, anychance you'd know how far apart where the elements of the structure supporting the deck? and how thick?

thanks again!

Gades

  • Waikiki Status
  • *
  • Posts: 24
    • View Profile
Re: plywood thickness for deck and bottom?
« Reply #4 on: April 19, 2011, 02:13:09 PM »
How durable do you want it? They make some canoes very thin, but the weight is distributed. For a SUP you will have a lot of force in one spot on the deck. the closer you make your frames (internal perpendicular supports) the thinner the plywood on the deck. If you think the board might be subject to hitting rocks, or seeing a shore break, then I would make the hull a little thicker as well.  When looking at plywood, get a tight marine grade ply in the 4 to 6mm (3/16" to 1/4").

We've got no rocks around here, and no waves. But, it'd be a board for beginners, so it'd have to get used to some "abuse".

Do you have any example of frames and deck measurements?

Ideally, I'd like to use marine plywood and a single layer of fiberglass with epoxy all around the board.

I've got some plywood in stock at work, so I'll be able to play around within the next few days.

Thanks a lot

JeffBach

  • Rincon Status
  • ***
  • Posts: 193
    • View Profile
    • Email
Re: plywood thickness for deck and bottom?
« Reply #5 on: April 19, 2011, 05:00:57 PM »
If memory serves, the CLC plans were $97 including shipping.  They are full size too.  All you have to do is trace and punch.  Spending the 97 on the CLC plans could save the expense of building a second board.  It did for me.

If you are going to truly do it custom, start saving cardboard boxes and don't bend them. Corrugated cboard is the perfect template for testing multiple iterations of custom built ribs. It's just about the same 6mm thickness.

I really was planning on doing two boards.  Going into the first one I was expecting all sorts of issues which have not yet happened.  If you are going the custom route, budgeting for two and building that first one as a somewhat sacrificial victim to learning might be the way to go, especially if you do cheap pine plywood on the first one and save the expensive marine plywood for the second one..

Gades

  • Waikiki Status
  • *
  • Posts: 24
    • View Profile
Re: plywood thickness for deck and bottom?
« Reply #6 on: April 19, 2011, 11:07:30 PM »
If memory serves, the CLC plans were $97 including shipping.  They are full size too.  All you have to do is trace and punch.  Spending the 97 on the CLC plans could save the expense of building a second board.  It did for me.

I thought about it, but the design is not exactly what I'm after. I found another one that was closer, but they only sell the whole package (a building kit, including the wood, but it'd be quite expensive to send it over here)

If you are going to truly do it custom, start saving cardboard boxes and don't bend them. Corrugated cboard is the perfect template for testing multiple iterations of custom built ribs. It's just about the same 6mm thickness.

If I can get away with something as thin as 6mm ribs then I could play straight away with cheap plywood (not marine).

As soon as I start doing something I'll open another thread to upload some photos.

Thanks everyone!

 


SimplePortal 2.3.7 © 2008-2022, SimplePortal