Replacing
Net Rails
by Scott McCulley
Engineers love failure. At least that's what my materials professor taught us in college. We learn more from a bridge that falls down than from one that stands the test of time. Or so I told myself as I extracted a piece of broken rail from my trousers after putting my foot through the port net.
The Tramp is a fairly solidly built boat, with the possible exception of the inboard rails supporting the nets between the main hull and amas. Haines Hunter drilled holes in a 9' section of 1/2" aluminum bar stock and pop-riveted it into a channel on the hull. Cut-outs in the hull allow the lashing for the nets to pass through. Unfortunately, the lifespan of an aluminum pop-rivet placed under shear stress is less than the age of my boat. When one rivet gives up the ghost that sets off a chain reaction, shearing additional pop-rivets until the rail breaks. I wanted to rebuild stronger than the original.
I examined my neighbor's F-24, which uses a mushroom anchor bolted through the deck edge. It was not possible to emulate with the Tramp's deck line. I talked with some other multi-hull owners at NWMHA and got several good suggestions for designing a stronger rail. One that sounded good was to fiberglass a plastic tube into the old channel and slide a rod through. It also sounded like a lot of work and would be difficult to match the faded yellow gelcoat. Without fiberglass, the plastic tube would be susceptible to UV and might not be strong enough. I decided to use an aluminum tube with pop-rivets and marine adhesive to get the same benefit with less work.
Demolition was easy. I drilled out the old pop-rivets and pulled the remainder of the old rail off. A razor blade peeled off the old silicon sealant. Then I lightly sanded to rough up the gelcoat to accept adhesive and cleaned with acetone.
| I used a metal file to remove the saw marks, then sanded with emery cloth to polish. I drilled holes in each end. Flat black paint matched the other metal fittings on the boat. | Tip: Don't worry if you have a few cuts that are not quite square. File down the high side on each end and use these pieces where the hull curves toward the bow. It will look like a custom fit, which it is! |
| Tools:
Electric drill |
Materials:
Qty 2, 1/2" OD aluminum bar stock, 12' long |
Last updated 11 Apr 2000