The walnut is very hard . . . and it's heavy. It will definitely add some weight to the boat. Probably not a bad thing since I removed about 1000 lbs of engine and fuel tank. The weight is low so it should make the boat a wee bit stiffer. It's probably not much but nonetheless it will not detract from stability. I could have milled it to 3/4" and saved a little weight, but I figure I am building the boat to last. If the walnut works out, at some point it will need to be resurfaced. the planks can be removed and run thorough a planer or cleaned up with a belt sander. They would look as good as new. The extra 1/8" provides for future maintenance.
While also working on the windvane I built and installed the frames for the deck hatches. These frame will not be visible. They span the gap between the open edge of the overhead panels and the fiberglass ovehead around the hatches . They also provide a surface for the vertical and horizontal finish trim to screw into. Though a precise fit was not required it still required tedious time consuming work.
After much thought, I decided it would be best to build one good sea berth. About, 23" wide at the shoulder and around 16-18" at the foot. The top will be about 12-15" higher than the original berth and positioned outboard against the hull. Inboard of the berth, between the nav station and the ladder, will be a 'thwart-ship watch seat. There will be storage under the berth and some between the berth and the longitudinal bulkhead that separates the quarter berth area from the ex-engine compartment. I might be able to fit a place to hang wet foul weather gear so we don't have to drag it through the boat.
I started off by attaching some temporary horizontal cleats. Then I erected strong-backs and small vertical cleats to help keep the lower dividers plumb and level when I glassed them in place. Next, I made templates with door skin plywood and a hot glue gun. I removed the templates and traced them on some 1/2" 1088 okume plywood. I checked the fit then removed an additional 3/8" off the bottom to accommodate the closed cell foam wedge. When I was satisfied everything fit properly, I sanded the hull with 40 grit abrasive as well as a 2" wide strip on both sides of the dividers. I vacuumed and performed a thorough acetone wash down. Next, I applied a couple of coats of epoxy to the end grain of the plywood and let it get very tacky. Then I clamped the dividers into place and wet out the hull and the dividers with unthickend epoxy. I wet out the tape and applied a 4" wide strip of 17.08 biaxial to each side. After that I cleaned up the boat and the shop. Later when the epoxy tape was green I trimmed the excess with a razor knife.
I found the blocks I needed--Harken #001 swivel bullet blocks with a 2 .25 diameter sheave. As hard as it is to believe, of all the places I looked, the best price, by far, is West Marine. They gave me a bunch of discounts. They had two in stock so I purchased them and ordered the rest. I chose bullet blocks because they have very little friction which will help to keep the vane sensitive in light air.
On the right side of the picture you can see the temporary piece of scrap pine 2x4, installed vertically, secured with hot glue and the Schaefer blocks that I used to develop the run. I have not drilled a hole in the center of the bronze plate as I need to get the right fitting--a SS eyebolt I think. Two block will be secured to it--one that supports the port side control line and one that support the starboard side control line. I can't really do much more till the rest of the blocks arrive. So, tomorrow I'll go back to work on the interior.
Note: I mentioned that I think Yves is very clever. In one of the pictures of the Cape Horn steering quadrant I added to the 7 Dec 11 photo gallery, there is a little rod you can see that fits in a special slot in the front of the HMT. It's only purpose is to allow a very small tiller pilot to link to the steering gear. This unique design feature allows what would normally be a low power (and low power draw) tiller pilot to steer a large boat because the tiller pilot taps into the self steering gear mechanical system to provide leverage via the steering oar. Yves points out that because the tiller pilot does not have to work very hard and because it will be in the lazerette and out of the weather it will last longer. The rod can be removed in a couple of seconds.
The most interesting event today was installing the brackets on the tower tube. The task was to get the tapped backing plates inside the tube, lined up with the holes I drilled, and the bolts on the fittings threaded into the tapped backing plate. Yves Gelinas, the designer and builder of the Cape Horn Windvane, and a very clever fellow, described how to do it in the instruction book. I admit I was a little skeptical but it worked like a champ. Take a look at the pictures below to see the technique. It's a technique worth keeping in one's bag of tricks.
The windvane is up, it looks good, and it seems to be very secure. It is nice to see the boat looking different. Tomorrow, I'll start working on rigging the control lines. I'll need to pick up some small bullet blocks, make some backing pads and take a closer look how/where to run the lines.
I'll replace the night time photos of the vane in the gallery below tomorrow with some day time shots.
So how does the windvane work? The windvane blade is set by the skipper so one edge is directly into the winds. The vane is push over (tilted) left or right as it responds to changes in the relative angle of the wind as the boat sails along. The vane blade is linked to the steering oar via a special connecting rod. A change in the windvane causes the steering oar to turn (left or right) and the water pressure then pushes on the steering oar (with great power) literally swinging the whole oar blade. The swinging of the steering oar (levering is probably a better word) causes the control axis to rotate inside the HMT, riding on those Teflon bushings. That rotation of the control axis is transmitted to the quadrant (bolted to the forward end of the control axis) you can see in the last picture. As the quadrant rotates it pulls on the control lines (they are not rigged in the photo below) that lead, via a series of small blocks, to either the tiller, wheel, or the boat's steering quadrant (if it has one) (three options) as you desire. It's all about the Cape Horn quadrant pulling on the control lines. That is essentially how the vane steers the boat.
Last, night I sanded the HMT on the outside in the area that will be glassed to the inside of the hole in the transom. Sanding the SS tube gives the epoxy something to grab onto so it won't slip. I also sanded the bottom of the plywood pads and the beveled sides with 40 grit abrasive paper. This morning, I started off by test fitting the whole lash up one more time. Next, I performed another acetone wash down of the area that will receive epoxy. Next, I cut some 17.08 biaxial to fit over the plywood pads that will be glassed to the inside of the lazerette. Then, I wetted out the bottoms of the pads and the area against the hull they will contact with. I let it cure till it was tacky. Next, I mixed up a batch of West Epoxy that I thickened with a small amount of 404 filler and the rest was 406 colloidal silica. I trowled it on to the bottom of the pad to create a small wedge to better angle the bad towards the HMT. I smoothed fillets around the pads and too the left over epoxy to make a fillet around the HMT on the inside of the hull where it passes through the transom.
I let all this cure till it was firm but not hard. Then, I removed the bolts from the pad end of the support tube and folded the tubes out of the way. Next, I wet out the biaxial, placed it over the pads, around the HMT, and smoothed it all out. I spent the rest of the afternoon reading through the directions for mounting the control tower and rigging the control lines.
Next, I made a simple jig for holding round stock when drilling. I took a scrap piece of 2x4 about 14" long and cut 2 opposing 45 degree bevels in it with the bevels joining down the centerline. This created a 1" deep 90 degree angled "trough" that will hold various sized round stock steady for drilling.
Then, I used the measurements for the support tubes from the mock ups I made yesterday. I cut the 7/8" OD SS tubes about 5" long with a hack saw. I used a sharpie to mark on the HMT where the swivel brackets would be located (each swivel is held on with two 1/4" bolts. These holes only go through one side of the tube. Cape Horn supplies a little custom curved and pre-tapped backing plate that fits on the inside of the HMT. I marked the location on the HMT for the two holes for each of the swivel brackets with a center punch. I could not get the jig to fit under my small drill press and have room for the drill bit to clear the 2 1/2" diameter HMT. So, I just set the jig on the floor and cut the 5/16" holes with a hand drill (these holes are cut slightly oversized to provide some wiggle room for fitting) . The jig made it pretty easy. Next, I needed to drill a 1/4" hole for the bolt that would hold one end of the tube to the "U" bracket (I installed the "U" brackets to 4'x4" plywood pads yesterday--see the previous entry for pictures of the pads and "U" brackets). This hole goes all the way through the tube so I used the drill press for the small tube, since it would fit under the drill press, and because this hole needed to be drilled at 90 degrees through both sides. Next, I assembled all the parts and test fit them in the boat. It all looked pretty good. I was running out of time and did not want to get in a hurry epoxying the HMT and the pads in position so I spent the remaining time cutting out biaxial cloth for the pads and a small strip for the HMT. I also spent some time beveling the inside and outside edge of the 2 1/2" hole in the transom. This should allow a better epoxy filet on the inside and a bedding compound caulking grove on the outside. I vigorously sanded the inside of the lazerette where the pads will be secured with 40 grit paper, vacuumed up the residue, and did a thorough acetone wipe down.
When I was ready, I started off by marking the center of the transom, vertically and horizontally, with a pencil mark. Then I drilled a small 1/4" pilot hole. I taped over the surrounding area to protect the edges and reduce the likelihood of damage to the Awlgrip paint when I drilled the required 2 1/2" hole with a hole saw. I would be lying if I said I was not a little anxious about drilling this hole. I spent some time making sure the drill bit was level by calibrating the drill with a bronze rod and a torpedo level. Once I was satisfied I knew what level was I installed the hole saw and made the cut. No sweat. The tube fit perfectly level.
Next, I inserted the horizontal mounting tube (HMT). It gets bolted in place with two 1" diameter SS support rods. The rods connect to the HMT on the inside of the lazerette and then to 4"x4"x3/4" beveled plywood pads that are glassed to the inside of boat. Then, to provide more strength, the HMT itself gets glassed to the inside of the transom as well. So, it is important to get the depth of the HMT just right as it become permanent to the boat. To determine the depth, I used a 1/4" line to hold the HMT level (see pictures below) and temporarily installed the control axis (lower part of the vane) which contains the toggle rod and to which the steering oar is also attached. The control axis is inserted through the HMT. The steering quadrant is attached to the forward end of the control axis that protrudes through the forward end of the HMT--a tube inside a tube, if you will. I wanted the vane tower be close to the aft end of the fantail but allow room for the steering oar to rotate up 180 degrees in the stowed position. I also checked that the quadrant, which gets attached to the end of the control axis on the inside of the lazerette, to make sure it will have room to rotate. The quadrant will be in the up position (see the photo below) when the steering oar is down but rotates 180 down when the steering oar is in the stowed, up position. Clear as mud, right? When I get further along and have more pictures it will make more sense.
Once I was satisfied the HMT was in the right position, I marked the tube on the inside with a sharpie. Then, I spent some time cutting the plywood pads that the inside support rods will be secured to. The brackets the tube get bolted two have to be through-bolted to the pads and the flat heads of the machine bolts counter sunk since that side will be glassed to the inside of the hull. I spent about 90 minutes just sitting in the lazerette with the pads, brackets, and some mock up 1" OD PVC pipe determining the best location for the support tubes to be located. I initially thought there would be lots of options regarding where the pads could be glassed to, but not so. The ideal location would have been under the aft deck but the dorades are there. A little closer to the centerline looked great but the lazerette hatch hinges fit there. A little wider and the antenna tuner would be in the way. Finally, I came up with a good location . . . angled down and to the lower side of the transom just aft of the quadrant. By the time I came up with the right location it was time to stop work.
The panels fit together down the centerline very nicely except for about 24" forward of the saloon deck hatch. Not sure why. It is a very small gap. I can't really do anything about it so I will get covered with mahogany trim and will blend in just fine with the deck beams and hatch trim. Many thanks to Kaj Jakobsen for taking an interest in our rebuild and for taking the time to provide a detailed explaination on how to make them.
The plan is to mount the stanchion supports about every six feet and in between them mount the support brackets. They are all 5" H X 3 1/2" L X 3" W. They are built out of 1/4" silicon bronze. We designed them so I can drill a hole in the upper horizontal plates at the top of the stanchion tubes and in the gussets of the support bracket and fasten shackles to them for halyards, preventers, etc.
Yesterday I radiused the corners using a template and a 4 1/2" angle grinder. I spent today polishing them up with a polishing compund that looks like a block of soap and a buffing wheel attached to my big grinder and clamped to a portable work bench. I wasn't looking for perfection since we will let them turn green with verdigris just like the rest of the external bronze. The buffing wheels slowly shred apart as you polish so I needed to do it out side. Last time I did this in my shop and it was a mess afterwards.
All these brackets will be bolted through the deck with backing plates. The raised bulwark will be through-bolted to the vertical plates.