Why not water proofing?

Discussion in 'Boat Tips' started by photocat, Jun 14, 2006.

  1. photocat

    photocat New Member

    Messages:
    803
    State:
    HOCO, Maryland
    I know there's alot of talk on the board about what to coat plywood in to make it best for boating... why not a couple of coats of WATER PROOFING???? i know its really not water proof... but it retards the water absorbsion a great deal...

    Its also alot cheaper then the other options like epoxy or marinegrade plywood...
     
  2. Dragger

    Dragger New Member

    Messages:
    538
    State:
    North Carolina
    Bryan, I just finished a rebuild on a pontoon this past winter, I used a sealer for decks to help retard the water, I've had no problems with it.
     

  3. ka_c4_boom

    ka_c4_boom New Member

    Messages:
    2,252
    State:
    Bedford,Ky
    deck sealer will work but it wont last long. being a painter , i would recommend cold tar epoxy applied to both sides of the board aswell as the edges its expensive but when done right would last 10x as long as any cheaper method
     
  4. Mark J

    Mark J New Member

    Messages:
    9,407
    State:
    Four Oaks, NC
    The reason why epoxy on marine ply is the best way is simple.
    Marine ply has no voids between the plies to trap moisture caused by condensation. The glue is a known waterproof glue. There is no maybe it is .
    The overall quality of the plywood surpasses anything made in the good ol USA because these types of wood dont check and weigh less. The strength surpasses anything available at Lowes or Home Depot.

    Epoxy is darn near waterproof at 99 point something or other depending on what kind you use.

    If you use anything else like the vinylester resins used for fiberglass or the many big claim low wonder products that are no where close to that of epoxy the problem is that that 4-20% margin of not waterproof does let water in even if it is minute in amount. Once in it doesnt come back out as easy or at all. This creates wet rot, mold, and mildew. All destroy wood.

    The other effect is dry rot. Boats do dry rot. Epoxy is the best sealer to prevent both. This is not opinion , it is fact. There isnt a boat yard in the world that doesnt use epoxy and marine ply on wood or composite boats.
    It is safe to use with no harmful fumes as in other products.
    A big key to sealing wood is bonding. Many products do not create the bond that epoxy was designed to do with wood.

    Using anything but epoxy and marine plywood is a FALSE economy.
    I dont want to rebuild a boat or build a boat from scratch that isnt going to last nor do I want to sell one I've used inferior materials on to someone that will experience the failure and thus start the talking behind my back that I dont know what I am doing or that I shafted someone. I value my reputation.

    Epoxy and plywood built boats have been sitting in saltwater permanantly except for haulouts for 30 years or more and still get carried well offshore on a daily basis.
    This in itself speaks for the longevity.
    You wont find as many glass boats that age still in service in the same enviroment.

    Its simple for me . Do it right the first time and enjoy the boat.
    I'm not into doing things 2 or 3 times until I finally figure it out anymore.

    Take it from me. The first one I did, I cut the corners. It is in worse shape now then before. That taught me to get off my duff and learn. I've spent untold hours days and weeks, months over the last 6-7 years researching, learning to use , and using these products. Failure rates dont exist if used as designed and maintained.

    Take it as the gospel or ignore it and reinvent the wheel later on.
     
  5. mspratt

    mspratt New Member

    Messages:
    173
    State:
    missouri
    A lot of builders are going to pressure treated ply wood with a glued vinyl.And givin a lifetime warranty(to the same owner)on the floor.Or try aluminum diamond tread flooring,cost lots more but last forever and its lighter than wood flooring..:cool2: ur humble servant beartrap and buoy
     
  6. ears

    ears New Member

    Messages:
    55
    State:
    *Required*
    It can depend the use as well. If I go through the trouble of fixing transom, stringers, deck etc. in a fiberglass boat I use epoxy. If you want it to last it is false economy not to IMO. On the other hand my buddys johnboat he uses painted exterior plywood for the floor. His floor sits on ribs and has no carpet so theres air all around it. It has been three maybe four years since he bought the boat and put the wood in and it is still good. Not to mention the fact he can rip it out and put new in, in about an hour.
     
  7. Mark J

    Mark J New Member

    Messages:
    9,407
    State:
    Four Oaks, NC
    the thought of ripping it out and putting new in if it needs it is where the false economy comes from.
    Done with the correct materials the correct way the first time it can be installed permanantly without a second thought. 3 million dollar+ yachts are built using the method everyday.
    Take a walk down the water front of any seaside town on Yacht row.
    I know what to look for and know what I'm looking at but the casual observer will never know. Many of those fancy boats are built from plywood and epoxy.
    Not treated plywood or acx plywood and definately not polyeurathane and will outlast a fiberglass boat.
    Anybody can cobble.

    Here is what I am talking about. If it works on these boats , it will work on any boat. These are all epoxy Plywood boats.
    http://www.jarrettbay.com/construction/fleet.php