Conference unifix::sailing

    George,
    
    If it's any help, I have a 27 year old plywood boat, which I sail
    and race almost weekly. It still has the original plywood - with
    the expection of a couple of half panels to repair race "dings".
    So that should tell you something about durability.
    
    I assume you realize that you have to use "marine" ply in boat
    construction. It's more expensive than the stuff you might use around
    the home but it's fabricated with waterproof glue.
    
    The one failure, I've had is that the glue between panels on both
    sides of my boat has aged badly. Not really surprising, glue technology
    has come a long way in 27 years. I "V" chiseled the join and re-glued
    using an epoxy based glue and haven't had any trouble since.
    
    As far as maintenance is concerned, all wooden boats tend to soak
    up water during the season and it's important to let them dry out
    periodically. I usually leave mine in a "freeze-free" environment
    for a couple of months in the winter to dry out naturally. That
    can be difficult in the UK but you shouldn't have much of a problem
    in Santa Clara if you put a loose polythene "tent" over your boat.
    
    Of course, a good paint and varnish job will restrict the amount
    of water going in so it's a good idea to do a close inspection while
    it's out. Since I race, I usually paint with a soft paint every
    year and gradually polish this off during the season. Other people
    I know use polyurethane based hard paints and get by on painting
    every couple of years.
    
    I don't have any experience with regard to like for like costs of
    plywood vs. wood but like most everything else, the major cost in
    boat building is labor and I can't imagine it being any quicker or
    easier to build in wood than it is in ply.
    
    I've never owned a solid wooden boat but I imagine that repairs
    are about the same unless you're using something exotic as an outside
    shell and the hull is varnished rather than painted.
    
    Hope this helps...Jon
    

                  -< my 2 cents >-

   I'm preparing to build a 33 foot trimaran from sheet plywood.  A big 
advantage of sheet plywood is that the building usually moves along at a 
rapid rate.  For me it's the simplest form of boatbuilding other than maybe 
steel, which, depending on your skills, maybe more difficult.
   If you use the WEST system of encapsulating the plywood with epoxy, 
maintenance can go down considerably.  I personally think anyone is crazy 
not to use epoxy on any kind of wooden boatbuilding.  Once an epoxy/plywood 
boat is built, the only hull maintenance needed is enough good paint to 
protect the epoxy from UV.  The hull can easily last a lifetime with little 
work.
   I'm not an expert on this subject, by far.  Talk to as many boatbuilders 
as you can, both professional and amateur.  Send away to epoxy retailers 
for their information and possible construction techniques.
   Three good books come to mind about plywood boatbuilding & boatbuilding in 
general, that may answer many of your questions.
   In the end I believe plywood boats to be a strong, easy, very realistic 
way to build a boat.

BOATBUILDING WITH PLYWOOD   by   GLEN L. WITT       <--Excellent Book

available from   GLEN-L MARINE DESIGNS
                 9152 Rosecrans
                 Bellflower Ca.   90706       213-630-6258

THE GOUGEON BROTHERS ON BOATBUILDING   by   same

available from   GOUGEON BROTHERS INC.   (WEST System)
                 706 Martin St.    Dept. B-B
                 Bay City, Michigan   48706

ILLUSTRATED CUSTOM BOATBUILDING  by  BRUCE ROBERTS

available from   BRUCE ROBERTS
                 PO Box 1086
                 Severna Park, MD.   21146

---------------------------------------------------------------------------

EPOXY RETAILERS

POXY-GRIP & POXY SHIELD     from     GLEN-L MARINE
				     see address above

SYSTEM THREE EPOXY          from     SYSTEM THREE RESINS
				     PO BOX 70436
				     Seattle, Wa.  98107

CHEM-TECH		    from     CHEM-TECH
				     4669 Lander Road
				     Chargrin Falls, Ohio 44022

WEST EPOXIES		    from     GOUGEON BROTHERS INC.
				     see address above

EPOXY ??		    from     CLARK CRAFT
				     16 Aqua Lane
				     Tonawanda, N.Y.  14150

				For what its worth
				BILL C.

RE: .2

>>>  I'm preparing to build a 33 foot trimaran from sheet plywood.  


May I recommend getting a copy of this year's World Multihull Symposium 
proceedings?  Most of one full day was devoted to construction methods, 
and those devoting time and comment to plywood/epoxy construction included 
Meade Gougeon, Derek Kelsall, Alex Kozloff, among others.  Many pertinent
comments which can help the amateur builder were offered.

Contact Multihulls Magazine in Quincy for info, though I presume you 
likely are a reader already.  If you're stuck, contact me at DTN 273-5344 
and I'll try to assemble some xeroxes for you.

J.

    Does anyone have any marine plywood scraps to sell?
    
    I'm looking for a piece with dimensions:    5" x 5" x 3/4"
                                             or 5" x 5" x 1"
    
    I'm building a lightweight aluminum motor mount (target weight 2.5 lbs)
    and need some plywood for the mounting surface.
     
    Thanks,
    
    Paul

    re: -1
    
    I had one of plywood.  covered with 7 coats of spar varnish.
    
    In a couple of years I had 2 thinner ones  :-)
    
    might want to try a heavier solid wood piece.
    
    Ron

    The last time I checked, marine plywood was identical with exterior
    plywood except that marine plywood is guaranteed to have no voids.
    
    My commercial outboard bracket must be made of exterior, cause it
    had a small (1/8 inch square) void. Filled with plastic wood, and
    many coats of varnish later, it looks super.
    
    Bill