Sunday, June 24, 2007

Shaping Hull Exterior and Glassing Keel

The new Rigid 6-inch random orbital sander has been getting a workout and has proved its worth over the past couple days. I turned the hull upside down and set it up on the new, extra-low sawhorses I built for the purpose and began the tasks of shaping the hull exterior. This involves fairing all the hard edges of the keel, skeg and stempost and filling and fairing the joints where the hullsides meet the keel and the topside joint where it overlaps the lower hullside. Getting a smooth, rounded keel was relatively easy after the epoxy filling the joints cured. I went ahead and laminated the first keel strip of glass over this - a 6-inch wide strip of 6-ounce cloth cut on the bias so that it will conform to the keel better. This will be followed by a wider strip of perhaps 10 inches, and then the cloth sheathing the hullside will also overlap the keel, making a total of 4 layers of 6-ounce cloth in the vulnerable area.

To lay the keel strip, I first taped off the perimeter of area I wanted the first strip to cover, then placed the overlapping cloth strips over the keel, letting them hang past the tape line. The cloth is then wetted out with epoxy, and the excess resin removed with a squeegee.

After the epoxy sets up enough so that the cloth does not easily pull away, but not so much that removing the tape is difficult, I cut the cloth with a razor knife just inside the edge of the tape line and pull the tape and excess cloth away. A second epoxy coat is applied immediately after that while the first coat is still tacky. Then it's left alone until full cure, when I will come back and sand it with 80 grit until it is smooth enough to lay on the next, wider layer of cloth.

The leading edge of the skeg needs to be rounded over to reduce turbulance and resistance as it moves through the water at speed. Here it's been partially shaped, but still needs more thickened epoxy at the hullside joints before it is completely faired and ready to glass.

Here's a front view of the upside down hull on the low sawhorses. I can't find any noticeable problems with the fairness of the hull panels. This hull really went together well and is going to look great. I just hope I can build another one just as well to match!

Another view at the bow. Filling and fairing all the details around the stempost and upper stringer is tedious and time consuming. I've still got a ways to go on this, but at this point all the main fillets are made and temporary screw holes in the hull panels filled. I'll be away from the hull a few days but when I return to the shed I hope to finish the exterior fairing and get the sheathing done.

Today I cleared out space in the other half of my workshed so that I can begin making parts for the second hull. I went ahead and scarfed the stringers for the lower hullsides this afternoon. The panels are all cut, epoxy coated and ready for assembly, as are the bulkheads and the stem and sternpost. I plan to assemble the lower hull panels and wire them together, but not set them up for installing the bulkheads until after I assemble the topside panels and glue up the mast. The reason for this is that I have a 26-foot long workbench in this half of the shed and I want to complete all these long parts before tearing it down and making space to set up and build the second hull. The fully assembled hull panels can be conveniently hung from the outer wall of the shed while the mast building process is going on.

Tomorrow I'm going to New Orleans to pick up some more Joubert BS 1088 Okoume plywood. This trip will be to get what I need to build the crossbeams, as well as the bunks for the second hull, and some of the 6mm for the decks and cabin sides of the first hull. I'm taking my stepdaughter with me on this trip and after picking up plywood at Riverside Lumber, we plan to go to the French Quarter for the afternoon and especially to the Cafe Du Monde for some cafe au lait and beignets.

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