Loading ...
Sorry, an error occurred while loading the content.
 

UHMW

Expand Messages
  • sals_dad
    There s been some discussion of UHMW plastics for bottom runners/sheathing for small boats; I just spoke with Pete, a product guy at Crown Plastics:
    Message 1 of 39 , Sep 12, 2002
      There's been some discussion of UHMW plastics for bottom
      runners/sheathing for small boats; I just spoke with Pete, a product
      guy at Crown Plastics: http://www.crownplastics.com/ 513-367-0238.

      They have noticed that boatbuilding may be a pretty good market for
      UHMW, and want to understand it better; they've had a lot of interest
      from manufacturers of drift boats, air boats, etc.

      In the past, you had to use at least 1/4" thick sheets, to allow for
      countersinking the screws. Since this isn't great in boats - too
      much weight, and lots of screw holes - they've developed two UHMW
      product lines that fit the bill - a pressure sensitive adhesive
      backed sheet, and a "treated for bonding" sheet. They think 3/32
      (.093") may be the best thickness for sheathing the bottom of a boat,
      in 12 or 18" widths.

      Pressure-Sensitive-Adhesive: Crown applies a 20 mil foam acrylic
      adhesive (mfd by Avery Denison) to one side of the sheet. You peel
      off the backer sheet (a little at a time) and use a firm roller to
      apply about 2' at a time, applying pressure, and rolling out air
      bubbles. This adhesive is supposed to be pretty good in a marine
      environment, but can be removed (with some difficulty) at a later
      date.

      Treated-for-Bonding: One surface is roughed up (my
      oversimplification) to allow a mechanical bond with epoxy or other
      glues. This sounds ideal for boatbuilding, but Pete warns that
      it's "permanent" - no removing it later, for any reason. At first,
      this sounds good, but what if it does wear out, or you need to make
      repairs on the underlying plywood... This system is used in
      snowboards, where you just discard the whole assembly...

      In either case, thermal expansion can be an issue (a real problem
      with thick sheets and screw fastenings); they recommend leaving an
      expansion gap (1/16") between pieces, and have processes in
      manufacturing to minimize later expansion/contraction.

      I pressed Pete for a ballpark cost, and he estimated $5-10 per square
      foot, depending... I'd assume more for a small (one-boat) order.

      Finally, they are looking for a local (Cincinatti) boatbuilder
      willing to work with them to test out products and methods.

      Sounds to me like there may be some great new products coming out,
      and I'm sure people will find creative new uses for them (a high-tech
      alternative to copper-plating for antifouling, anyone?).

      Curtis
    • Bruce Hector
      A very nice looking example Ken! How does she row? I like your colour scheme. Where are you? And don t listen to anyone, you re not pazzo, I am! Bruce Hector
      Message 39 of 39 , Jul 4, 2003
        A very nice looking example Ken!

        How does she row? I like your colour scheme. Where are you? And don't
        listen to anyone, you're not pazzo, I am!

        Bruce Hector
      Your message has been successfully submitted and would be delivered to recipients shortly.