The start of our last week. Geoff began the day with a few tidbits. He reminded us that the parts we began making (rudder, centerboard, etc.) should be store flat; they will warp despite relative thickness. Scarf cleanup was reviewed: heat gun plus scraper followed by 60 grit sandpaper. Then, talking about planking, Geoff demonstrated that if a batten seemed unfair, you can measure the plank at that point and take the corresponding measurement off the mold.
We created the pattern for plank three, faired it, cut the blanks, measured, and then cut the planks. For seem reason (the hour? Too much coffee?) I cut a less than smooth curve that obliterated the line at several points. Geoff to the rescue. After much eyeballing and measuring, he began correcting the edge with a bench plane (#4?) and at the very end, a block plane. We lost only a 16th of an inch from the design width...within tolerance. The gains were then cut as were the rolling bevels on the two #2 planks. The planks were offered up and some corrections made.
The bevel was wetted out (un-thickened epoxy) to saturate the end grain. This was quickly followed by thickened epoxy. The plank was held in place with clamps and temporary screws. Screws had been placed through the plank on molds 3,4, and 5 in the last fitting and then removed. The holes in the planks and molds could then be used to correctly register the planks. The whole process was repeated for the plank on the other side. In each case, squeeze out epoxy, inside and outside, was cleaned up.
Hahn was sent under the boat to do something besides clean squeeze out. He was given a drill with a ½ inch bit and asked to drill a holes near the ends of the centerboard slot. It was a tough job because the bit was last sharpened by Noah. Still, he succeeded admirably. Geoff then cut the whole slot using a straight router bit with a guide on it that rode on the keelson and cut the plywood to conform.
Next we began the last plank – the sheer plank – which is the one that catches the eye and can make or break the looks of a boat. In order to place the luan on the boat to create a pattern, notches had to be placed on both sides of the stems (saw and chisel) on the 2x4's to allow the pattern to reach down to the shear strake marks on the stems.
The planking process was the same. I was reminded that after the plank is marked and cut in three pieces, and scarfed, it is aligned with the pattern placed over it. The second plank is placed on top of the glued and scarfed first plank, which serves as its pattern. When we cut the scarfs this time, several of us used hand planes (I used my jack plane and block plane) and we all felt more comfortable than with the power plane. We had much better control. The scarfed planks were held in place with strongbacks rather than screws this time.
Geoff then had us return to working on the parts previously started. One operation involved rounding off the rudder head using a router with a pattern bit: 3/8” radius on the solid part and 1/4” on the sections where there was no middle section.
Next we (read Geoff) studied the plans and planned how to cut the timbers for the aft end (skeg, etc). He then made up a cut list of oversized lumber for the forward keel, aft keel, etc. We then milled these parts to their rough dimensions. Brian planed the bottom of the boat so planks were no longer protruding and thus created a flat spot for all of the parts were were in the process of making.
Some rudder theory. The railing edge should have a small flat area and then gently sweep down for about four inches. We placed the rudder in the rudder head and marked how far up this feathering would extend. The feathering was accomplished with the big grinder/sander initially (36 grit) – about half way up to the 4” mark. Then the standard 4” grinder was used with 24 grit on rubber sanding disk (this tool is used often by welders) to sculpt the edge of the rudder.
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| End of the Day Progress |
All photos of the Ness Yawl 2011 class may be viewed at: http://www.flickr.com/photos/21597525@N00/collections/72157627358772597/
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