Since the curves of a catboat are more exaggerated than those of a C&C 34 I was not comfortable building by shaping the lifts alone. I decided that it would be great to have a three dimensional template for measuring the shape of the hull. So I made a set of station templates from the lines drawing and mounted them in a board with slots cut at the correct station offsets. Since the individual templates are press fitted into the board, they can be removed for measuring individual hull sections. once the hull is completed it should fit exactly into the three dimensional template.
Here is a look at the 1/16th scale plans.
A close up of the templates mounted in their station slots.
Since the pine stock I had was not quite wide enough for the beamy catboat, I ripped one board into 1" wide lengths, and glued then to some 3 1/2" wide boards. This gives me 4 1/2" wide wood to work with which is plenty.
Nov. 2, 2005 (Wednesday) Begin cutting out buttock slices and waterline lifts
David Prairie has came over to help and learn. While waiting for him, I made a drillpress jig for the 4 1/2" by 6" sanding drum. a saddle square and a platform for mounting the model in the vice so that I can use both hands to use the chisels and spokeshave to shape the model.
David arrived, and we started by planing down some lumber to the thicknesses that we would be using. Since I could not find lumber in 3/4" thickness, I bought 1/2" finger jointed paint grade pine and laminated two pieces together. Now we just had to reduce it to the right thickness. In order to do this I got to use my brand new Thickness planer.Busy Bee Tools, Model B2437. It worked great, but snipes a bit. We used a digital 4" caliper to measure the the thickness of the planks between runs through the planer.
It makes big piles of wood chips.
Once we had our wood to the right thickness, we used one of my Lee Valley pouncing wheels to mark the inboard buttock slice, cut it out with the band saw, and finished shaping it with the drillpress and the 4 1/2" by 6" sanding drum. We then marked the centreline and waterlines onto it.
Here are some action shots of David working with the pouncing wheel and the sanding drum.
We continued the process cutting out the LWL, WL 36", WL 42" and WL 48" waterline lifts, planing lumber to the required thicknesses as necessary.
LWL = 7/16", WL 36" = 5/16" and WL 42" and WL 48" are 3/8" thick. Each lift was marked with the centreline. We aligned them, and stacked them and then drilled them and put dowel in them. At this time they still need shaping with the sanding drum, so we did not glue them together or to the buttock slice. There was some confusion at one point about how they stacked on the buttock slice, but it was quickly resolved by planing the WL 36" lift and making a new LWL lift.
At the end of the evening we had these pieces, and a huge pile of planer chips.
Next time We work on it, we will make the buttock slices for the bottom, the sheer and mark the rabbet line on the inboard buttock slice.Then it is time to remove all the wood that is not part of the boat.
Nov. 3, 2005 (Thursday)
I cut out the two remaining buttocks and a small section of the WL 24" lift, I did final shaping on all pieces, and glued it all together.
Below we see a minor miracle of clamping.
This left the sheer lift. I copied this from the plans using the pouncing wheel and cut it out. It was then glued on top of the WL 48" lift.
This left a lot of wood above the sheer line as can be seen below. I debated my options on this, and since the half hull is too high to use on my bandsaw I decided to have a go with the spokeshave. The half hull was clamped into the vice, and away I went.
I used the spokeshave and the drum sander to remove most of the wood above the sheer line. It will need further sanding tomorrow if I get a chance. I had to stop because some of the glue was not dry enough and was starting to loosen. I reglued, and am leaving it overnight. I found that using the spokeshave on the finger jointed pine to be difficult. The unpredictable grain caused a lot of grabbing and chattering.
The half hull after spokeshaving and sanding the sheer.
A small part of the sheer line was still projecting above the WL 48" lift. I glued in a small piece in this area. It will be shaped when I finish sanding the rest of the sheer.
Doing just this much work on the sheer suddenly started to make the hull look like a cat boat.
November 4, 2005 (Friday)
I finished the shaping of the sheer using the drum sander.
I wanted to mark the rabbet line on the inboard side of the first buttock slice. I realized that the easiest way to do this would be to build the keel and then trace along the line where it meets the bottom of the buttock slice. Since the keel has to be made some time, I decided to follow this path. The keel has a profile that is about 1/4" thick in the area of the centreboard and about 1/8" aft and forward. The stem is also 1/8".
The keel was not glued on at this time. That will be done once the hull is shaped. The keel would interfere with tool use and using the templates to measure the hull at the stations.
November 5, 2005 (Saturday)
I went to Noah's Marine Supplies today and bought a dressed mahogany plank 7/8" x 9 3/4" x 58". This is enough wood to make two backboards. The plank will have to have the edges trimmed and it will have to be planed so the actual board will be a little smaller.
The half hull after spokeshaving and sanding the sheer.
