Tuesday, January 06, 2009

Shaping and Glassing the Rudders, More Beam Glassing....

I spent most of the holidays away from the building shed where I have the hulls, but I was able to get back to work on some of the parts I have stored in my girlfriend's garage. As detailed in a post long ago, the rudders have been drilled for lashing to the sternposts and epoxy insets made to prevent rot from the lashing holes. The main rudder blades for the Tiki 26 are cut from 18mm plywood, with 6mm doublers on each side in the upper area above the waterline to the top of the posts where the tillers fit on. The lower sections of 18mm ply have to be sanded down to a hydrofoil shape on the trailing edge to decrease turbulence. This was accomplished with a belt sander first, and then the random orbital sanders shown below. The glue lines between the layers of ply serve as a guide in maintaining a consistent thickness.

Here the rudders are resting across the three crossbeams while the first coating of epoxy cures.

You can see the sanded tapers and the epoxy insets with lashing holes drilled.

Cold weather forced me to move the rudders inside for fiberglass sheathing. I'm fortunate that Michelle is a creative person who always has projects going in her studio and doesn't mind an occasional boat sub-assembly in the house.

In the photos below the fiberglass sheathing on the lower blades of the rudders has been laminated with epoxy. The upper areas with the doublers will be sheathed as well. The corners on the upper parts are well-radiused to receive sheathing all the way around. Every ply part of the boat that is exposed to the sun will be sheathed in 6-oz. fiberglass.

Back in the garage I worked on the crossbeams as well. Sheathing them is a multi-step process because of all the surfaces involved.

This application of fiberglass is on the top plate of the forward beam. Masking tape put on in advance of the fiberglass and epoxy defines the edge and allows it to be cut straight. The next application of fiberglass on this beam will overlap the edge of this layer and extend down over the front plywood fairing, wrapping around the leading edge to the bottom. The sheathing involves lots of steps and filling the weave and fairing all this out will be a considerable amount of labor as well, but worth it to prevent possible checking and water intrusion into the beams.


Anonymous said...

Plus, as a friend of mine said after seeing me glassing the front beam, "anything you run into will break first!" :~}


Scott B. Williams said...

That's about right, Kim, unless you hit it with the forestay bridle first. David ran smack into a channel marker with his Tiki 30, motoring at 7 knots (don't ask how). The only thing that broke was one of the wooden masthead cleats that hold the shrouds. At least there is enough redundancy in the rigging that he was not dismasted.