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Thrashed hull on cedar strip canoe.

Discussion in 'Strippers, Stitch-n-Glue, and Other Wood Composite' started by Daniel Day, Sep 22, 2009.

  1. Daniel Day

    Daniel Day Enthusiastic about Wooden Canoes

    Hello all,
    I am back from Upper Priest Lk. Idaho this past weekend. It was great. Canoed about 20 miles. Beach landings and portage. The canoe was loaded down but had room for more equip. The hull survived well, but it does have some deep scratches.
    I have two questions,
    First, I need some sort of inner framework to put stuff on. Ribs maybe? Floor?
    Second, I have some Z Spar for the hull, but is there anything thicker? Or would I apply multiple coats to get a thickness?
    Thanks,
    Dan
    PS, I will attach pictures when I get them developed. I use an old 35mm camera for trips.


    Finally got the pictures developed. Hope they turn out. The long scratch is deep.
    Andy, The hull is strong enough to walk on. I had thought about rubber mats, but thought the ribs would distribute the weight better. The one picture is of Upper Priest Lk. looking south, not to early morning.
     

    Attached Files:

    Last edited: Oct 5, 2009
  2. pklonowski

    pklonowski Unrepentant Canoeist

    Pictures will be most helpful... Can't really tell what the scratches need without the visuals, inside & out. Some wear & tear is to be expected... did you want a coffee table, or a boat? :D
     
  3. OP
    OP
    Daniel Day

    Daniel Day Enthusiastic about Wooden Canoes

    Paul, I did not buy it to be a coffee table, it is too big for my living room. Am working on the pictures. Still need to know if anyone has had success adding ribs, for stiffing and putting gear on.
    Thanks
     
  4. pklonowski

    pklonowski Unrepentant Canoeist

    Mine's too big for the living room, too... the family room, on the other hand, has easier access to the outside... but my wife doesn't like the idea! :D

    Are the scratches through the top layers, and into the weave of the glass? If so, dry it our really well, top coat with a layer or two of epoxy, then sand & varnish. You probably won't get the weave to disappear like nothing ever happened, but it'll protect the wood until you do a major overhaul. If they're not into the weave, just sand & varnish.

    If there's actually a crack in it, and it goes into the wood, keep it off the water until after the repairs. You'll need to use a heat gun to loosen the cloth around the crack, cut off the big chunks, sand to feather the cloth to the wood, dry it out really well, patch with glass cloth (at least 2" beyond the edges of the crack) & three epoxy coats, then sand & varnish.

    I kept patching mine over the years, and eventually cracked it up well enough to have to remove the glass, inside & out, and re-glass it. Patches on top of patches just wasn't going to work. Still haven't quite finished the job... the hull, seat, and thwarts are done, waiting to work on new gunnels.

    Do a search in this (Strippers) forum, and see if ribs come up? I don't recall reading anything like that, but that means I've slept since then. They'd certainly make later repairs a whole lot more complex, which may not be what you want to do. A removable floor rack might be a better idea, but remember that any grit that gets under the rack may get stuck between the rack and the hull, and may become scratch generators. My guess is that it's a trade-off, but I haven't tried it myself.
     
  5. helgin

    helgin Curious about Wooden Canoes

    I just had my stripper up near Upper Priest a couple weeks ago. Fantastic canoeing up there. Can't wait to get all the way to Upper Priest and camp.

    Anyway, I put 4 half ribs inside my canoe after testing it in a pool and finding it too flexible. With my woodworking skills, it took a lot more time than I figured it would. Instead of putting on flexible ribs, I put 1" thick ribs that I individually tapered to match the curve of the hull. Epoxied them in place after sanding off the hull's varnish. In the end it worked great and they would be perfect for distributing the load of heavy items, or helping keep them in place. But since you are not talking about any flexing issues, then some 1/4" thick half-ribs that you epoxy in place with some weights to get them curving should work fine. I got lots of great advice in another thread here from the springtime, so check that out.

    But, it seems like there would be some thick rubber mesh or something to put on the floor instead that would be easy and not add weight to the canoe.

    regards, Mike

     
  6. OP
    OP
    Daniel Day

    Daniel Day Enthusiastic about Wooden Canoes

    Thanks Mike,
    I have a couple of ideas. Just need to put something down to put my gear on.
    Upper Priest Lk. has no road access. Boat or hiking in and is a great place to camp. Lots of wildlife. Saw bear sign, but no bears.
     
  7. Andy Hutyera

    Andy Hutyera The Red Canoe Guy - Life Member

    Maybe I'm way off base, but if the only issue is protecting the bottom of the canoe and not one of strength, why not try one of those open weave nonslip mats that they sell in the carpet department of the big box stores. It's fairly light weight and durable and can easily be cut to shape to fit nicely inside the canoe. It's not very heavy and wouldn't add much weight. The down side is that since it's open weave it will let dirt through which might get under the mat and cause some abrasion of the hull. Since the stuff seems to stick in place there may not be much movement to the stuff thereby reducing the likelihood of abrasion.
     
  8. Rollin Thurlow

    Rollin Thurlow member since 1980

    Adding ribs that are well spaced out can result in local areas that are much stiffer than the rest of the hull. These "hard" spots in the hull can result in hull damage because areas that once could flex can not give as they once did and will now break under the same strain that did not cause any damage before.
    A lot depends upon how the hull is used but its one thing to consider before adding ribs and making hard spots in the hull.
     
  9. Dan Lindberg

    Dan Lindberg Ex Wood Hoarder

    It's hard to tell from those pics, but, that looks like normal use/scratches to me.

    IF they go to the glass, revarnish, I've heard of a method (but haven't tried it yet) of wiping varnish on with a cloth, it just fills the scratch and doesn't add a whole new coat.

    On the other hand, if they go through the glass, you will need to sand and add a structual patch, ie, fliberglass and epoxy resin, top coated by varnish.

    But most likely they are normal scratches, don't worry about them until the end of the year and then sand and add a coat of varnish or 2, or not. :)

    Dan
     
  10. Todd Bradshaw

    Todd Bradshaw Sailmaker

    Our standard procedure was always to clean the hull bottom and touch up the scratches with varnish, without worrying much about getting everything level or filled (varnish is pretty crappy filler). Then, we would go in every two or three years and do a more substantial job with some sanding, epoxy filling, re-leveling and a fresh coat of varnish (which you need for U.V. protection from time to time anyway). You can tell ahead of time whether varnish will hide the scratches by wiping the area down with water and seeing how many of them disappear.

    You may find some spots where a scratch is deep enough to have "bruised" the fiberglass. These spots tend to be whiter, don't go away completely when wet, and may show some weave pattern. New varnish or epoxy filling may hide them to some extent, but it's likely that they are now permanent and not something that can be fixed by typical maintenance touch-ups. You would probably have to go all the way back down to bare wood and re-glass the area to completely get rid of them, which is far more trouble than they're worth. Boats get used - and that's OK. The exception would be any spots showing delamination, which need to be fixed pronto. You might find them at severe impact areas and the glass will look semi-transparent, like a hunk of a plastic milk jug, and will move when you push on it. Luckily, with modern epoxy resins, these aren't common. It will usually abrade, bruise, fracture or even break without losing its grip on the wooden core - which is good.

    As for ribs, if the hull doesn't need them to hold its shape, you would be making stress risers (stiff spots that concentrate damage) as Rollin mentioned. If you think you have bad scratches now, just wait until you repeat the same trip with ribs added. It would seem to me that a couple of waterproof pack liners would weigh a lot less than ribs or some sort of floor rack. I always have at least one dry bag inside my Duluth pack containing a core group of stuff that I want to keep dry under any and all circumstances (sleeping bag, a dry set of clothes, anything filled with down, etc.) The rest of the stuff in the Duluth will survive if it happens to get wet. If for some reason you really need to get the packs up off the floor, a foam pad or your Therma-Rest mattress would do it without screwing up the boat or adding weight.
     

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