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Synthetic sealant

Discussion in 'Birchbarks, Dugouts and Indigenous Craft' started by tostig, Jan 25, 2008.

  1. tostig

    tostig Curious about Wooden Canoes

    I've seen rubber used to seal the stitching but I can only get my hands on the polyurethane sealant used for doors and windows, but it doesn't work that well after it gets all dried up and hard with the constant dipping in water.

    What synthetic rubber sealer do you use and where can I get some in Toronto?

    (I've also sealed with spruce gum but I've gotten a little tired of the high maintenanance - still like gum for the authenticity and the asthetics).
  2. JBP689

    JBP689 Betula Canoe

    My 35 year old BB has it's first and only poly application still on it. It has weathered many whitewater adventures with concommitant rock encounters. It is roofing quality poly. No clue what your locale has to offer, but maybe an internet search is indicated.
    The old pitch/grease/charcoal is nice, but those nightly applications during the fur trade era must have been tedious.
  3. HarryA

    HarryA woodwrecker

    Butyl Caulk?

    In the world of steel roofing they use Butyl has it has to
    stretch with the steel and be long lasting.
    for example:
    Aluminum and Metal Sealant Butyl Caulk White - 10 ozs
    Aluminum/Metal Sealant Butyl White - Size 10.1 ozs - Cartridge

    must come in other colors.

    How does silicone sealant stand up?

    also this site has sealants:
    3M Marine Sealant 5200
    "Color - Tan. The seal is extremely strong, retains its strength above or below the water line. (Great for bedding a keel) Stays flexible too - allows for structural movement.
    Has excellent resistance to weathering and salt water."

    there are up your way; also have lots of canoe and kayak plans...
    Last edited: Jan 27, 2008
  4. OP

    tostig Curious about Wooden Canoes

    Thanks, for your inputs. They seem abit exotic. Are these products currently available at, say, Home Depot or a specialty roofing shop?

    I was mentioning that some of the rubber sealant I've seen used on birch bark canoes were real rubber - like car tire rubber but spread on like paint or putty.
  5. Denis M. Kallery

    Denis M. Kallery Passed Away July 3, 2012 In Memoriam

    Try a roofing company that installs rubber membrane roofs. I got some from such a company for use with the roofing material. It came in the small caulking gun size. Good luck.
  6. bob goeckel

    bob goeckel Wooden Canoe Maniac

    i've used PL brand polyurethane from lowe's or home depot with excellent results on classic boats and other marine applications. it's alot cheeper than 3m 2500.
  7. peter osberg

    peter osberg LOVES Wooden Canoes

    try 'boatlife', a polysulphide rubber, it stays flexible and is a bit more like a hard rubber than butyl, and lasts more than a few decades by my count; if they still make it. peter
  8. beaver

    beaver Birchbark CanoeingBuilder

    :eek: For me as a builder of bark canoes for almost 30 years now, I just can't bring myself to use something other than the natural materials that traditional people have been using for Centuries. Why go through all the work it takes to build a fine birch bark canoe and then smear on some rubber prior to launching your work of art on a pristine lake??:confused:
  9. HarryA

    HarryA woodwrecker

    natural materials

    In the world of natural materials how would you use pine resin?
    I see you can get it from:
    at 12$/lb.

    How much would you need to coat 6 feet of gores?

    On the cover of Gidmark's book "Building a Birchbark Cane" the canoe
    appears to be sealed with white material; pine resin?

    Also in searching on the internet I see it is used to cook potatoes
    in - wonder what that taste like?
    Last edited: Jan 31, 2008
  10. beaver

    beaver Birchbark CanoeingBuilder

    It takes around 2-3 pints to seal the average canoe including the ends + also sealing the seams on the inside of the canoe prior to installing the sheathing and ribs. By pitching the canoe on the inside it gives double protection against leaking.

    My secret recipe includes spruce or pine pitch, wood ash, bear grease, and a little bee's wax. Apply to the seams and ends hot off the fire. Then go paddling eh.:cool:

    Attached Files:

  11. tedbehne

    tedbehne Birchbark model builder


    Pine rosin has been used commercially since the 19th century as the basic ingredient in most glues. As anyone knows, who has had the misfortune to get it on their skin, it is among the stickiest substances in nature. When used as a sealing agent for bark canoes however, it has some drawbacks. Both pine and spruce rosin (preferred by many canoe builders for its reddish color) crack in cold weather and run and drip in hot weather. Native builders partially overcame these problems by tempering them with a bit of animal fat, which helps to resist both cracking in the cold and melting in the heat. They also learned to keep their canoes out of direct sunlight when not in use.

    As for cooking potatoes, mashed turpentine isn't my favorite, but who knows what others may like.
  12. rakwetpaddle

    rakwetpaddle paddle dipper

    Plastic cane, black walls on a Cadillac, butyl; what next?

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