This summer, I tackled the chainplate knees on the opposite side of our Bristol 26. There were two knees on this side–one for the upper shroud, and one for the aft lower shroud. The forward knee is in the locker across from the head. It looks like it’s in much better shape, so I can leave it alone for now.

Here’s how it looked soon after we bought the boat. There’ were some fiberglass covers over the knees, and some carpet and a felt liner covering the inside wall.

I thought about my options for a while and decided to prep the plywood counter, then fiberglass a piece of plywood on the top. There was a large gap between the countertop and the boat hull, but the plywood was in good shape and would provide a good surface to work with. by bonding another piece of plywood to the top, I could close the gap to the hull. Then I would fiberglass the new knees to the hull, the underside of the cabin top, and the plywood piece that put on top of galley counter. I originally thought of replacing the entire plywood galley top, but I didn’t want to get into that big of a project. After all, I did want to go sailing this summer.

Here’s the soggy plywood and chainplate knees after I started disassembly.

Since the boat was in the water with it’s mast up, I decided to replace one knee at a time. It was a bit more time consuming but, I figured that the mast needed more than just a forward lower shroud to hold it up properly.

Here’s the aft lower shroud chainplate knee. You can see how small it is, with the upper bolt hole right at the edge of the knee.

I took the lower storage area on top of the galley counter top apart, then trimmed the laminate so it wouldn’t be under my repair. I wanted to save the laminate replacement for another time, but wanted to make it easy to remove when the time came to replace it.

The knee on the port (dinette) side was easy to pry off, but the two on the galley side were still bonded too strong to pry off without causing damage to the hull. You can see the bottom pulled away from the hull, but the upper part was still attached. I used a multitool to cut the knee out, then used a grinder and flap wheel to take care of the rest of the fiberglass. It made a terrible mess. About halfway through the project, I purchased a Ryobi cordless vacuum, which made cleanup much easier. Being on a mooring, we’re limited to cordless tools for now–an inverter is on the upgrade list, but it’s probably a year or two away.

You can see the gap at the top of the forward chainplate. All of the force that the shroud exerts ends up pulling the hull inward and is what causes the bottom of the chainplate knee to separate.
I took some measurements so I could position the new chainplates correctly when we’re putting things back together. In this picture, you can see the large gap between the counter top and the hull.
Here’s what was left after I cut the chainplate out. Unfortunately, it took a lot of grinding to get to a good surface for the new chainplate knee, and made a dusty mess out of me and the cabin..
I used an old outdoor sign to make the templates for the plywood pieces. It was easy to cut with scissors, and is rigid enough to hold its shape. It worked much better than the cardboard I had used previously.
On the deck, I used Crayola kid’s clay to make a “dam,” then filled the void with slightly thickened epoxy. this elevates the hole through the deck and should help the new chainplate stay leak-free.
I’ll jump ahead and show you the finished (but unpainted) raised platforms for the upper and lower aft shroud. They haven’t leaked yet.

I bonded the lower piece of marine plywood to the back of the counter, and the aft lower knee to the hull using thickened epoxy. After that, I cut all the pieces of biaxial cloth to size. Prepping this before mixing the resin makes the job much quicker and less messy. I used 4-inch biaxial cloth for almost all of the fiberglassing. The only areas that got lighter cloth were the inboard edges of the chainplate knees.

I took this photo after I reattached the aft lower shroud and started fiberglassing in the knee for the upper shroud.

I made new chainplates, then used the old ones to serve as backing plates for the bolts. I have more details about this process in my write-up on the dinette side repair I completed the previous year.

After a coat of TotalProtect Primer and some Sherwin Wiliams urethane enamel to match the rest of the cabin.

Replacing the knees was probably the biggest item on the to-do list, so I’m pretty happy to get this project done. I’m also happy with the brighter, freshly painted look. The cabin is a lot drier now, too.

Related Reading: