Friday, February 1, 2019

Strengthening chainplate knee

It has been unusually cold the last few days as a record-breaking "polar vortex" has covered the Midwest and we catch the tail end of such storms here in St Augustine, so I've just basically hibernated rather than work on the boat.

But I still managed to get a couple of things done. One was to consider insulation and the other was to strengthen a chainplate knee

The boat came to me with the interior side above the starboard settee already down to bare fiberglass. There was a splotch of gelcoat on the surface so I suspect someone was considering just gelcoating the area but stopped because the weave pattern of the fiberglass would show. I have sanded it down so it is relatively smooth now but I intend to cover the area with insulation so I'm not as concerned with looks (but I will be gelcoating the surface to protect it anyway)

Meanwhile I have taken the opportunity to strengthen the knee where the aft stb chainplate attaches. I drilled a hole into the knee to made sure the wood inside was still in good shape and it seemed to be so there was no need to replace the knee, however I want to take this chance to strengthen it. I have epoxied-in 1/3-inch thick plate made of G10 high-pressure fiberglass laminate to act as a back plate for the chainplate, waiting for it to cure (put a heater nearby) before sanding it back a bit so I can put strips of fiberglass directional matting to extend the knee a couple of more inches, and get it really stuck well to the hull interior. Then, I will smooth it out with fairing and wrap it in some laminate wood veneer. The chainplate itself attach on the outside, over the veneer, so I can check it visually regularly


  1. Not sure why looks are important. Aren't the knees mostly hidden from sight? I just removed the chainplates for inspection and new hardware (bolts and nuts) on my P35.

    1. Looking neat & tidy suggests a job well done; that's why looks are actually important on a boat.