Sunday, June 4, 2017

Fixing the Centerboard

After quite a long writing break, I thought it would be good to catch up on the blog a little.  The biggest bit of news is that I finally resolved Solitude III's stuck centerboard.  

A centerboard that goes down is a sight for sore eyes!
It was an issue that plagued me for well over a year and a half.  It started after a weekend cruise, when I noticed that the centerboard seemed to drop a little less freely than before.  Things slowly worsened, and soon I was needing to open the inspection ports and push the board down using the hand of a pair of channel locks.  It kept taking more and more force until, on day, it would not go down.

My first suspicion was that there was some flotsam jamming the board, but on inspection, I could find none. One day I dropped the boat into the water, pulled out all the ballast, secured a line to the masthead and hauled her over onto her side. I then waded into the water and set to work. Between prying with a screwdriver and applying excessive force, I managed to get the board ALL the way down. The was a little bit of seaweed and the like on the board and in the trunk, but nothing major. I cleaned it as best I could. I then tried running the board back in. Still very, very jammed. 

After eliminating lodged debris as a cause for my centerboard woes, I determined that there had to be  some water intrusion that was causing swelling.   The question was whether it was on the centerboard side or the trunk side.  It was getting toward the end season, so I parked the boat jacked it up slightly off the trailer and let it spend the next five months out of the water, airing out. 

After quite some time, I launched the boat and tried it again.  Still stuck.  From there, between the discouragement of having a stuck centerboard and having a total lack of time to actually make progress, things bogged down.

Finally, I got serious.  I built a new centerboard, and re-careened the boat.  Out came the old board, in went the new.  Except it didn't.  Stuck.  This time I came armed with diagnostic tools, namely a few sticks of varying thickness from less that 3/4 inch (the thickness of the centerboard) up to 1 inch (the original width of the trunk).  I probed carefully and determined that the wood at the bottom of the centerboard trunk had swollen.

The root cause of the problem was that, in my rush to finish the boat, I sanded through the epoxy/fiberglass in the neighborhood of the centerboard slot and didn't reseal it. The breach in the epoxy was just at the bottom of the keel, so water was getting lapped up via the "endgrain" edge of the plywood. The one "for sure" spot that I found was about `at the midpoint of the centerboard slot lengthwise, and actually on the outboard edge of the keel. I have been known to be a flagrant violator of maxims such as "always keep your sander flat against the surface" and "don't use a power sander on edges," and in this case, I was roundly punished for my transgressions.

After consultation with John Harris, I decided to strip the paint in the area, apply liberal doses of epoxy to seal it, repaint, and replace the centerboard with a 1/2" one covered with two layers of 'glass.  In addition to patching and resealing the one clearly obvious spot, I also overreacted and hit everything within 2" of the centerboard slot (around the keel, and yes, up into the slot) with several coats of epoxy.

You don't want to do this to your boat if you can avoid it.
For the resealing of the slot, I was able to jack the boat up off the trailer far enough to gain access. I used the careen-at-the-dock procedure to get access to the board for installation and removal.

After I got her back together, re-rigged, and in the water last night, I raised and lowered the board.  Smooth as could be.  I took her out for a brief test cruise, but the wind forgot to show up. It wasn't until a week later that I had another chance to go sailing.  The trip took me across from Coupeville to Port Townsend to sail by the Wooden Boat Festival (which I had not registered for, since I did not know I'd have an operational boat in time), but that's a story for another time.

Under Sail Again!