Repairing Rotten wood under mast step on 470 dinghy. What kind of wood to use?

Discussion in 'Sailboats' started by Philippe Thuillier, Jul 13, 2020.

  1. hoytedow
    Joined: Sep 2009
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    hoytedow Wood Butcher

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  2. Philippe Thuillier
    Joined: Jul 2020
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    Location: Portland, Oregon

    Philippe Thuillier Junior Member

    Some really good comments and questions.
    This is how big the step is, the base of the mast for on the screw going across

    Attached Files:

  3. tlouth7
    Joined: Jun 2013
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    tlouth7 Senior Member

    I doubt the type of wood matters, but you need to really tidy up the hole it drops into and make sure the fit is good. You might want to use thickened epoxy to ensure you don't leave any gaps at the join.

    You need to seal the screw holes to stop water getting in through there and rotting the wood inside its fibreglass sheath. The best way would be to drill out oversized holes in the wood, fill with epoxy and then screw into those plugs (having drilled pilot holes). You may consider this overkill but if you have already made up a batch of epoxy it shouldn't be hard to do.
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  4. fallguy
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    fallguy Senior Member

    There is no way you removed all the rot. It looks spongy/fibrous underneath. You gotta get in there and scrape with a chisel man!

    Wood never rots on a clean line for your replacement conveniences.

    When using the chisel; do not strike it with a hammer; just scrape out the rot. Once the rot is fully removed; bed a piece of wood into thickened epoxy, but not much more than 3/8" thick or it may catch fire.

    Please don't build back over rot.

  5. Philippe Thuillier
    Joined: Jul 2020
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    Location: Portland, Oregon

    Philippe Thuillier Junior Member

    Thanks so much
    We did a thorough job at cleaning all rotten wood , chisel gently extra pieces and put a new piece of pine wood which was heavily bound to the boat. After filling it in we layered with fiberglass , sanded , drilled pilot holes , filled in with epoxy and screwed the last step in . Everything looked sturdy and sealed by the time we were done
    We let it cure 24h and we just enjoyed the last week end enjoying once more our very speedy 470. Wind cooperated and everything seemed to hold very well even under quite windy conditions.
    Thanks so much for all the great comments and suggestions. Let s hope this holds for many years.

    Attached Files:

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