better to crew into wood or epoxy

 I plan to attach a standard rudder mount to a Chesapeake 17. Based on the current size of my stern end pour three of the rudder mount screws will be going into epoxy and the other three will not hit anything at the moment. Since I need to add to the end pour to grab the other three screws should I just pour in more epoxy or should I pour around a chunk of rot resistant wood (like black locust or white oak) to give at least three of the screws something more to bite into than just epoxy? Will screws hold better in wood than epoxy?

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RE: better to crew into wood or epoxy

   Really wish I could go back and edit the posting title with the missing "s"

RE: better to crew into wood or epoxy

I asked myself the same question when attaching rudder hardware to the hull of my Waterlust canoe last year. The recommended Drill-Fill-Drill technique protects vulnerable wood from water intrusion while at the same time reinforcing the structure of wood fibers adjacent to fasteners that penetrate so there's some logic to thinking that epoxy alone may offer greater holding power than just the wood itself.

But when there's precious little wood where you want - or need - to install fasteners, what then? At the curved stern on the Waterlust there's no end-pour to provide bedding, just a deep fillet reinforcing the rather steep angle joint between hull panels.

Turning to available research done by the brothers Gougeon – who played a big role in bringing epoxy technology to the boat building scene back some fifty+ years ago – I took articles like this one to heart. So I cast an aluminum powder-reinforced block of epoxy into the stern where I intended to place the lower rudder hardware then drilled & tapped it for the machine screws holding the hardware in place. Total length of the threaded bores is roughly 7/8" where two of those 1/4x20 screws come together on the inside, leaving no room for fitting a nut.

There's more out there supporting this procedure, notably by Mike Waters who's designed and built many popular trimaran watercraft, once of which is his W-17 CLC makes kits for. You can read more on Mike's website.

(And I too wish there were at minimum an <edit> button here....)

RE: better to crew into wood or epoxy

Apologies about double-posting that last bit, and missing the link to the article I wanted to highlight on Mike's website.  

RE: better to crew into wood or epoxy

Thanks for all of the articles!  I have been looking them over for a few weeks.  Time to commit.

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