Tuesday, October 15, 2013

I Think God is Mad at Me

I'm not sure what I did, but based on what I found in the cockpit this weekend, I clearly pissed somebody off.  I figured that I would ultimately need to re-core the cockpit sole, but I did harbor a faint glimmer of hope that the deck would be sound because there wasn't any signs of sponginess or flex at all.  Apparently, the teak decking must have really stiffened things up because when I finally got to it, the core was a complete mess.  

To say that removing the teak decking was difficult is a serious understatement.  The tenacity of that black goo seam compound is just ridiculous.  It was so tough that in some cases it tore up the underlying deck and the teak often actually cracked and broke while pulling it up.  In some cases I couldn't even pound the pry bar underneath the planks because the compound absorbed all the blows and bounced it out.  Eventually I came up with a method of pounding a flathead screwdriver under the plank to lift it slightly and then was able to get the pry bar under to rip it up.

When I finally exposed the actual deck, it was a patchwork of holes and old repairs that were probably done (poorly) to stiffen the decks instead of actually addressing the real problem of the bad core.  So, armed with my skill and saber saw (for cutting the corners and around the scupper areas ) I cut the perimeter of the deck leaving 2 inches or so exposed for reglassing later.  I cut across the deck in a few spots as well to make it
easier to pull off the deck if the core decided it was going to be clingy.

When I was satisfied that I had made all the necessary cuts to pull the deck I found that it was still clinging hard and couldn't easily lift it off.  Very surprising given that it was pretty clear that any core underneath was very soft.  I took a wide chisel and scraped off some of the remaining teak seam compound on the deck thinking I missed some fasteners that were holding the deck down.  I partially solved the mystery when I found a bunch of 1/2 bolt heads underneath the seam compound that corresponded to three mahogany beams bolted to the underside of the deck running athwartship.  I always assumed they were original, but never paid much attention.  However, with the seam compound scraped off I could see the bolt heads right on the surface of the deck.  I can only assume that a previous owner bolted them on prior to installing the teak in hope of stiffening the deck (again instead of addressing the core problem).

With the teak planking off and nothing to help stiffen the surface I could see that the beams would actually move, so they were only bolted on, not glued to make them part of the structure (and increasing the deck's stiffness).  Ultimately I cut around the bolts to pull the top skin of the deck off, but it was still holding on hard. I finally just said f-it and tore the thing up with as much force as possible thinking that rebuilding the entire deck would not be the end of the world.

With part of the top skin off, the mystery of the tenacious deck was finally solved.  At some point in the boat's history, somebody did realize the core was bad and decided that using a hole saw they would drill out a series of 3" cores and refill them with epoxy and then add some floating deck beams (they are not attached to any supporting structures). I suppose it is a reasonably standard approach if your goal is to stiffen things up a bit and avoid entirely re-coring the deck, but in my mind it isn't really fixing the problem, it's a bandaid approach that will gain you a few years but truth be told, the teak planking was really the only thing that was giving the deck any substantial rigidity.  I should also say that using this approach makes it WAY harder to fix down the road when you want to do it right.

Anyway, I ripped up the rest of the deck and found 6 of these hole saw fixes and one for what I assume is the original pedestal mount location (at some point in the boat's history, the pedestal steering while not original, was moved to the forward end of the cockpit).  Unbolting the beams from below proved surprisingly easy considering (my definition of easy has changed drastically over the course of this re-build) and now there is much better access under the deck.

The core was as expected a smelly, mushy, stew and was best scooped with a garden trowel.  Once I cleaned and vacuumed everything up I was left with a swiss cheese like bottom skin of the deck and the solid glass plug for the rudder post.  Knowing that I will be glassing in a new rudder tube and glassing it structurally to the deck, I cut out a big square where the old rudder tube passed.

From there it was pretty much standard re-core prep work; tape all the holes from the underside to keep epoxy from dripping down, brace the underside so when weight for laminations is added the deck won't sag, and then sand everything down with 60 grit paper.  I didn't bevel the perimeter because I don't see the need to maintain the same deck height, I will probably lay in 2-3 layers of biaxial to build it up flush with the perimeter and then add 2-3 layers more on top of the perimeter to tie it all together.

I finished the day off by mixing up a small batch of epoxy and filled in the bigger holes with 2 layers of biaxial fabric and then thickened up the remainder of the batch and filled the myriad of holes in the deck.  I left the big square hole as is for now while I figure out the new rudder tube arrangement.  All in all, it was much more work than I had anticipated, but at least I can start rebuilding now. Stay tuned...

1 comment:

  1. Glad to see you're still at it, Matt! Cold has about shut me down too, but I've made some progress in the cleaning up and stripping hardware off the deck.