April 11, 2009
Block Repair Phase I
I spent the day repairing the block that broke free last Wednesday.
It's a three stage operation. The big problem I've encountered is the problem of applying enough force to clamp the wooden pad in place. In the past, I used a clamp set up as a spreader with on end against the deck the other against the wooden pad. I was never satisfied with that method because the spreader was never an optimum length. Another problem was that spreader pads never bore perpendicularly on the block and the deck, so when pressure was applied using the clamp, often it would slip.
This time, I tried something different. I reasoned that the big problem was one of stability in the clamping system. If I could somehow create a perpendicular surface for the spreader to bear on at an angle that was close enough to perpendicular at the wooden pad being bonded, I was confident I could get a good solid bond.
Since my boat is a Spindrift with a hull liner, there are shelves on the port and starboard sides of the hull under the cuddy. I built a spanning member out of a 2"x4" with supports on the ends to clear the wooden rails on the shelves. Here's a photo:
The support was a 3" long piece of 2x4 attached at the ends. The black material is black plastic placed to catch any epoxy that drips.
I dry-fitted the clamp and the wood pad to make sure it would hold properly.
To bond the pad to the surface, I mixed up some West System epoxy with enough micro fibers to thicken it to the consistency of mayonnaise. To keep the clamp for being bonded accidentally to the pad, I placed a piece of waxed paper in between. It also keeps any epoxy from dripping on the clamp.
After it cures, I will lay up some fiberglass around the pad to provide some additional strength. That's for the next entry.