Restoring structural integrity after canoe gunnel removal?

Discussion in 'Fiberglass and Composite Boat Building' started by UtahSignature, Jun 5, 2021.

  1. UtahSignature
    Joined: Jun 2021
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    UtahSignature Junior Member

    That's interesting - foregoing gunnels and option for PVC pipe! How would I bend it around the curvature of the canoe shape?
     
  2. ondarvr
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    ondarvr Senior Member

    PVC pipe of the size you'd use will bend easily around a big arc. If you need a tighter bend you can heat it up with a heat lamp.

    A gunnel is a location/part on a boat, the material it's made from is irrelevant.
     
  3. fallguy
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    fallguy Senior Member

    The thickened epoxy is all buried in glass.
     
  4. ondarvr
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    ondarvr Senior Member

    Tapering the edges of the crack eliminates the need for any putty, the area is thin, so another layer of glass will probably be all that's needed to build the surface back up.

    Even though epoxy Is relatively strong, without glass it's still much weaker than with it. And a putty bond is weaker than a resin and glass bond.
     
  5. mc_rash
    Joined: Aug 2020
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    mc_rash Junior Member

    Actually a nice idea with the PVC tube, and by the way a cheap one. But I would recommend before you do that to fix the cracks with small patches of glas and the whole edge with a strip of glas. Just to be sure that there won't be new cracks in a while due to movements of the hull. You do not need thickened epoxy for tbe cracks.

    If you think the gunnels made from PVC are not stiff enough I would use wood.

    Since you are "a bit of a perfectionist" I also would take the chance to paint the hull's outside. A clean job is much easier without the gunnels.
     
  6. fallguy
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    fallguy Senior Member

    All well and good, but I never advised putty without glass. The putty is only there to avoid entraining air in the repair.
     
  7. Mr Efficiency
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    Mr Efficiency Senior Member

    I'd be inclined to source a suitable aluminium extrusion for the gunwale. I think they are sold in 20 foot lengths, pop rivet it on.
     
  8. ondarvr
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    ondarvr Senior Member

    You aren't relying on the PVC for anything other than an easy to work with uniform shape, the laminate is contributing the strength.

    This means the it can be weaker or stronger than wood depending on his desire or needs. An extra layer of glass or two will increase the strength dramatically.
     
  9. Blueknarr
    Joined: Aug 2017
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    Blueknarr Senior Member

    I've used PVC pipe gunnels. Works wonderfully.
    Allow for some draining.
     
  10. UtahSignature
    Joined: Jun 2021
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    UtahSignature Junior Member

    Hello all!

    Coming back to this. I'm hoping to work on the canoe this weekend.

    Still torn between:

    A) Running an entirely new strip of fibreglass down each side of the canoe (if so, would I do both sides, as in fold the fibreglass over the lip - or just one side?)
    B) filling the holes with epoxy and filler

    My goal is to add more structural integrity where lots of random old gunnel screw holes are located.

    Any advice appreciated! I plan to order my materials today so I can do the job this weekend.
     
  11. aaronhl
    Joined: Aug 2012
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    aaronhl Senior Member

    If you fold fiberglass over the edge of the canoe you are going to run into so many other problems because it will not form unless you have a radius built up there. So many ways maybe proper or not to fiberglass...

    I would tear all that wood and nails out brush it off so you have all fiberglass showing along the edge of the canoe.
    Use 2" masking tape to tape all around the outside of the hull where the holes are.
    Then mix thickened epoxy mixed with chopped fiberglass strands and go all along and fill each of the holes, smear epoxy in the bigger gaps and use a plastic spreader to fair it out because you wont need much epoxy.
    If you need to strengthen some areas put small pieces of fiberglass cloth in those areas with epoxy.
    Epoxy in a new wood cleat all the way around.
    Ill post pictures of my boat
     
  12. UtahSignature
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    UtahSignature Junior Member

    Thanks so much! Would love to see the pictures.
     
  13. ondarvr
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    ondarvr Senior Member

    Back to my prior suggestion.

    Forget the holes, they are meaningless.

    Clean up the lip and sand it, add one or two layers of cloth as needed. You could do one on each side, or two on one side, won't make much of a difference.

    Don't fold it over the top, it won't work.

    But first decide on what the gunnel will be. If using wood it will benefit from a little added support. PVC won't require you to do anything to the lip, you can leave it as is.
     
  14. missinginaction
    Joined: Aug 2007
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    missinginaction Senior Member

    Since the OP is just learning to work with fiberglass I'd suggest that he use fiberglass tape rather than cloth. What do you think ondarvr? I could see him getting a good result using say 3" wide tape with a selvage edge that keeps it from unraveling. This would add the reinforcement he needs and make for a tidy installation with minimal sanding.

    Once the tape is on he could cap it with the PVC and he'd have a nice gunnel.

    9oz Fiberglass Cloth Tape https://www.mertons.com/Reinforcements/cloth_tape.html

    MIA
     

  15. ondarvr
    Joined: Dec 2005
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    ondarvr Senior Member

    If covering it with pvc there's no need to even touch it.

    Cloth and tape are the same thing, narrow cloth can be called tape. So yes, tape. Even narrow tape may need to be cut though, not sure how narrow of stuff he can readily get.
     
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