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Gap filling material

Discussion in 'Strippers, Stitch-n-Glue, and Other Wood Composite' started by Chipper1959, Jan 23, 2012.

  1. Chipper1959

    Chipper1959 Curious about Wooden Canoes

    I've almost arrived at the sanding stage on my cedar strip/fg 16 footer and quickly realizing that there's going to be many gaps which will need to be filled.

    Most the articles I've read say to use epoxy mixed with wood flour or sawdust to fill the gaps but I'm a bit hesitant to use something as hard as epoxy on something as soft as cedar.

    Has anyone used the fillers sold by Lepages or other companies which are used to fill nail holes ? These fillers sand very easily and are available in several shades. The only thing I'm wondering about is how they would react to the resin.
  2. pklonowski

    pklonowski Unrepentant Canoeist

    I haven't used the other fillers, but the wood flour/epoxy mix works very well. Mix it in to peanut butter consistency, force it into the gaps with a putty knife, and make sure you level out the surface as best you can before the epoxy starts to cure. This last step will minimize the sanding necessary. You may want to check the inside, to make sure your filler isn't creating bulges of goo, while you're working the outside.

    Good luck, and post pictures! We like pictures...
  3. OP

    Chipper1959 Curious about Wooden Canoes


    I cut and routered my own strips...(and I'm thinking I didn't do a very good job). It's looking like there's going to be a lot of sanding,scraping and swearing.

    I'm really hoping that the fiberglass will hide a lot of the built-in defects.

    If I learn from my mistakes I'll be a genius once this is finished.
  4. pklonowski

    pklonowski Unrepentant Canoeist

    I don't know that this looks any worse than most at this stage... and I've seen a few strip & glass boats that have looked a whole lot worse than this at this stage, that came out looking great. Maybe use a little less glue, so you don't get so much squeeze-out, but what I'm seeing in the picture really isn't that bad. I've used a block plane before sanding to get the worst lumps out, or a spokeshave will work nicely, too. Whatever you use, make sure it's sharp enough to shave your arm, and re-sharpen often. Keep up the good work! It'll be beautiful!
  5. KAT

    KAT LOVES Wooden Canoes

    I built a stripper last year and did have some gapping issues as well. I used the thickened epoxy technique and found a combination of wood flour and filler worked best. Most of the wood used was very light so the darker wood flour showed like a sore thumb, so the west system filler which is white, helped tone it down. Where I had access I would put a strip of masking tape on the inside before applying the filler on the outside, which kept it in place and lessened the clean-up on the inside later.
    We cut our own strips and scarfed 53 of the 87 strips it took to build the boat, and we did our own bead and cover routing as well, which wasn't the easiest thing and had issues with the cove edge breaking off, but sanding took care of most of that.

    As the strips went down I would wipe the glue up that oozed out before it could set up, and did so on the inside as much as possible, but still had a heck of a time cleaning the inside. Scrapers came in real handy there but you have to be careful since the glue will be harder than the wood.

    I know where all the boo boo's are but most anyone else never sees them and for a first build it came out really well.
  6. Todd Bradshaw

    Todd Bradshaw Sailmaker

    You could switch to DAP Weldwood Plastic Resin Glue (either for all the glueing or as a gap filler). It's pretty cheap, dark tan colored, it matches cedar pretty well, and sands easier than epoxy. It's a powder that you mix with water and it is by far the best stripper glue I've ever used. I can't imagine why folks would glue strips with either epoxy or glues like Tightbond when this stuff is available. You can get it from places like Amazon if you can't find it locally.
  7. Larry Westlake

    Larry Westlake Designer/Builder

    UF glue endorsement

    I'm with Todd on this one. I've been using urea-formaldehyde glues (DAP wwprg is UF) for over 30 years with success.
    All that I have tried are more convenient to use than epoxy and give better results.
    In 1985 I built a 12-foot stripper with UF glue and no fiberglass or epoxy at all. Ribs were glued in instead of sheathing. It held together nicely for 10 years, only cracked when I tripped and fell down inside it when portaging over some washing-machine sized boulders (I cracked too, and I was not particularly fagile at that time).

    Not bad for a total cost of $35 (1985 price). Weight was also 35.
    Those two low factors were the design goals. Except possibly for that difficult combo of objectives though, I don't recommend an all-glued stripper.

    Can post a pic if anybody wants.

    I am now testing a lamination of UF-glued fir laid up in 1990 that has been left outside to fail since 2001.
    So far no luck - its still together.

    Larry Westlake
  8. BFC fan

    BFC fan Enthusiastic about Wooden Canoes

    I'd like to see that boat
  9. Larry Westlake

    Larry Westlake Designer/Builder

    Here she is...


    This pic probably summer 1992.
  10. BFC fan

    BFC fan Enthusiastic about Wooden Canoes

    That's awesome, I've been thinking about this same idea for my next build. How about some scantlings? Strip thickness? rib size, material and spacing? How did you install the ribs? Did you use a keelson?
  11. Larry Westlake

    Larry Westlake Designer/Builder

    Answers to those questions and more at:

    It's too big to post here. T'woulda been rude.

    Larry Westlake
  12. BFC fan

    BFC fan Enthusiastic about Wooden Canoes

    Good stuff, thanks Larry

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