Kevlar Canoe Repair Question

Discussion in 'Fiberglass and Composite Boat Building' started by RTinkess, Aug 30, 2017.

  1. RTinkess
    Joined: Aug 2017
    Posts: 4
    Likes: 0, Points: 1
    Location: Ontario

    RTinkess New Member

    IMG_0383.JPG I've got a 14 foot Scott Elite Kevlar canoe. It's got a few hairline cracks on the stern.

    My question is if these cracks need to be repaired and if so how would you recommend repairing them
     
  2. ondarvr
    Joined: Dec 2005
    Posts: 2,929
    Likes: 573, Points: 113, Legacy Rep: 506
    Location: Monroe WA

    ondarvr Senior Member

    What does the inside look like?
     
  3. PAR
    Joined: Nov 2003
    Posts: 19,126
    Likes: 498, Points: 93, Legacy Rep: 3967
    Location: Eustis, FL

    PAR Yacht Designer/Builder

    Agreed, what does the inside of the laminate look like. Those appear to be flexural in nature and likely is just the resin yielding. It's unlikely the fabric is compromised, though if left unchecked, eventually the fabric will "hinge" at these locations and become damaged.
     
  4. RTinkess
    Joined: Aug 2017
    Posts: 4
    Likes: 0, Points: 1
    Location: Ontario

    RTinkess New Member

    I dont have a picture but the inside looks fine, I don't see any cracks or lines.
     
  5. PAR
    Joined: Nov 2003
    Posts: 19,126
    Likes: 498, Points: 93, Legacy Rep: 3967
    Location: Eustis, FL

    PAR Yacht Designer/Builder

    What's on the inside; ribs, seat(s), etc. around this area that could explain the flexing?
     
  6. RTinkess
    Joined: Aug 2017
    Posts: 4
    Likes: 0, Points: 1
    Location: Ontario

    RTinkess New Member

    IMG_0385.JPG
    The cracking is in between the back seat and the stern.
     
  7. PAR
    Joined: Nov 2003
    Posts: 19,126
    Likes: 498, Points: 93, Legacy Rep: 3967
    Location: Eustis, FL

    PAR Yacht Designer/Builder

    It looks like the stress cracks mitigate through the laminate stack, though not on common paths, clearly not enough "structure" to prevent flexing comprising the resin. The fix is to grind down through the surface resin, but not enough to cut fabric fibers, install some reinforcement (which can be one of several things), then apply a resin repair over the cracks, before flood coating the surface again. These types of cracks are common to see in larger unsupported areas on a single skin GRP hull shell. You'll note just under the thwart braces and seat, the cracks get progressively smaller and all but disappear. This is because the seat and it's braces help support the hull shell, preventing excessive flexing. In the areas away from this localized support the cracks appear. Can you provide an overall shot of the whole one end of the inside of the boat, so we can see the structure?
     
  8. RTinkess
    Joined: Aug 2017
    Posts: 4
    Likes: 0, Points: 1
    Location: Ontario

    RTinkess New Member

    IMG_0369.JPG IMG_0370.JPG
     

  9. ondarvr
    Joined: Dec 2005
    Posts: 2,929
    Likes: 573, Points: 113, Legacy Rep: 506
    Location: Monroe WA

    ondarvr Senior Member

    If you grind into Kevlar it turns into a fuzzy mess, so try to keep from doing it.
     
Loading...
Similar Threads
  1. Sneddy71
    Replies:
    12
    Views:
    4,209
  2. ahender
    Replies:
    21
    Views:
    5,997
  3. gastagg
    Replies:
    3
    Views:
    3,598
  4. jnicho33
    Replies:
    6
    Views:
    3,581
  5. delmarx
    Replies:
    0
    Views:
    2,103
  6. Jim Caldwell
    Replies:
    14
    Views:
    8,535
  7. mwwinklerdc
    Replies:
    20
    Views:
    8,649
  8. mikes8500
    Replies:
    2
    Views:
    2,879
  9. HAMMERHEADHM
    Replies:
    10
    Views:
    3,300
  10. hardcoreducknut
    Replies:
    9
    Views:
    2,751
Forum posts represent the experience, opinion, and view of individual users. Boat Design Net does not necessarily endorse nor share the view of each individual post.
When making potentially dangerous or financial decisions, always employ and consult appropriate professionals. Your circumstances or experience may be different.