The best protection for the wood core is a coating of epoxy resin. The West System epoxy is specially formulated for maximum water impermeability and I recommend it highly (System 3 is excellent stuff too for boats).
West Marine sells a kit (#101 Handy REpair Pack) that includes two premeasured twin-packets of resin with hardener, #404 high density thickener, gloves, cups, brush mixing stices for about $8 or you can get 6 twin-packets for $13.70 without the gloves brush, etc.
You have three choices in terms of how you protect your wood core:
1) Least preferred: Just use bedding compound. Only protects the core until the bedding compound leaks. Polysulfide bedding compound is the recommended stuff for this type of application, and should last 8-15 years.
2) Pretty good method: Paint a thin coat of epoxy inside the hole, being careful to cover the wood very thoroughly. Pretty good unless you inadvertantly scrape off the epoxy when you insert the new fitting. You may want to enlarge the hole 1/32" larger than your fitting before you coat it. That way you probably won't scrape off all the expoxy when you put the new part in. Bed the new drain part with polysulfide caulking (should be good for 8-15 years)
3) Best method: Drill out the existing hole 1/4" larger than your replacement part. Fill the hole with expoxy thickened with West 404 (High Density) or 405 (filleting) thickener. then redrill the hole to the correct size, leaving a 1/8" ring of solid epoxy all around the edge. This 1/8" will protect the wood from water incursion. (A variation on this method is to drill the hole, then dig out 1/8" of balsa-wood coring all around and then fill with epoxy. However, that would be difficult if there's any plywood reinforcement instead of balsa). Bed the new drain with polysulfide caulking.
For a "how-to" article on method #3, take a look at my webpage at http://hometown.aol.com/jblumhorst/GennyTracks.html. It's a "how-to" on installing genoa tracks, but it has detailed instructions and pictures of method #3.
Fair winds,
Judy B
1985 WWP19 #266 Redwing
SF Bay, CA
---------- Original Message Follows
From: Kristin Hammit[SMTP:ispania@prodigy.net]
Sent: Saturday, December 11, 1999 1:24 PM
To: Potter List
Subject: cockpit drain
<<File: ATT00000.htm>>
Hello,
Last weekend I was trying to fit a plug for the cockpit drain. I had noticed that the bi-lip plastic insert was rather worn (looked like UV damage). Well, when I pulled the plug out the whole thing flat-out shattered. Now with the rain and whatnot I am concerned about water damage to the wood core, ect. I contacted IM by email twice and have yet to receive any response (it seems that when you have a purchase inquiry that they somehow become lightening fast...). Anyway, that was before my water damage concerns.
So, what do I do to go about repair/protecting the raw wood that is now my cockpit drain. Is there a part I can get from West Marine or something? All input is appreciated!
Thanks,
Kristin