Monday, 31 January 2011

Yard and Daggerboard work

Another weekend has come and gone allowing time for some high-quality wood butchery!

So that a start can be made on some of the hull panels I cleared some space in the front room and brought through two of the Plywood sheets (yes, I do have an very understanding and long-suffering wife) so that I can mark out one of the hull sides. A series of lines are drawn on the two sheets at 300mm intervals and on these lines marks are made to show the position of the top and bottom of the hull side. The designers method of hammering pins into these points and then bending the faring batten around the pins was a really good way of ensuring a fare shape was drawn onto the ply, it was also really clear where a nail was not quite in the correct position.

Drawing the side panels

The yard had already been planed down to a taper but was still square in section, in order to make it round I needed to make a spar-gauge, this is a tool that helps mark-up a square spar so that it can be planned to an almost round shape. In true wood-butcher style I made one with the best “trial-and-error” method and the Mark 6 spar-gauge worked reasonably well and allowed me to plane down the yard to an tapered octagon shape. The yard was then planed to a 16 sided shape freehand and we have ended up with an almost round spar, I just need some long lengths of sandpaper to round off the final edges. The yard is surprisingly bendy, it is designed to be bendy but I need to measure this flexibility against some existing flex data recorded on the designers website. The sail will be cut to reflect the amount of flex in the yard but I don’t want to to be so flexible that the lightest of gusts means that I lose sail shape. If there is too much flex I may have to think again about the use of carbon fibre tube for the spars (but using the wooden mast).

Spar Gauge

The final job of the day was to continue with the dagger board, the blank had been laminated but this needed cleaning up and thicknessing to 22mm. As I don’t have a thicknessing machine this was done with my latest ebay purchase, a large No6 bench plane. The cedar is relatively soft and easy to plane but the oak that was chosen for the leading and trailing edge of the dagger board was very hard work even with a freshly sharpened blade. While playing games of hide-and-seek with my eldest son I slowly get the blank pleasingly flat and to the required thickness. The shape of the dagger board was then drawn on the blank and cut out with a jigsaw. Next I need to make up the designers foil profile template so that a sweet profile can be planned into the dagger board.

Daggerboard with mast and yard behind

Monday, 24 January 2011

Mast and Yard wait for no man....

This weekend the progress had not been quite as quick as the previous weekend, however the mast is now pretty much complete. The edges of the mast have be under the router to round them off and I have filled the few nicks I made in the wood while building. The mast just needs some glass around the bottom end and a coat of Epoxy all over to seal. I have started shaping the yard that has a taper at both ends but there is still quite a bit of work to get this completed, probably another couple of evenings.

I have just been reading on the Storer Boats forum about a couple of GIS owners than have had a Carbon Fibre rig made that has resulted in a big weight saving aloft. While the racer me would like to have a carbon rig it does go slightly against the idea of a simple to build and relatively cheap boat. I believe that she will sail well with the standard rig I am building but it would be interesting to have some boat-on-boat tuning time to see how well the various tweaks and changes work in the real world.

Monday, 17 January 2011

Lots of wood shavings and a three sided mast

A satisfying and successful weekend of wood-butchery has just passed and a decent first step has been made into the building of this Goat Island Skiff. I also made piles of wood shavings and ended up taking a few pics, some of the shavings look like rose flowers.

Friday night was spent marking out the narrow staves for the hollow Douglass Fir mast, these were then planed down as necessary to give the mast its taper. The instructions suggest doing each stave individually but as the planks I have are nice and straight I planed them down together giving me two identical staves and lots of shavings to sweep up. Some time on Saturday allowed me to make the blocks that are internal to the mast and hold the staves apart at the correct distance, one long block at the bottom with small spacers running up the inside of the mast. The spacer blocks were all made from lightweight Cedar.

Finally the time came to glue it all together so I applied packing tape to one of the wide staves to act as a support for the first gluing operation. The ladder of narrow staves and blocks were laid out and clamps were all found before the epoxy was mixed up and thickened. Starting at the bottom of the mast the epoxy was applied and then clamped before moving from one spacer block to the next until the top of the mast had been glued and clamped.

As I was in an “epoxying” mood and it was reasonably warm (for the time of year) I decided to glue up the cedar blank that the daggerboard will be made from. This was 7 lengths of Cedar with an length of Oak along the leading and trailing edges. I fortunately have a nice flat table that makes a good platform for this so it was covered in packing tape before the wood was glued and clamped to the table.

I had a few hours available on Sunday so started by inspecting the mast and daggerboard now that the epoxy had all hardened. The daggerboard blank was fine and I cleaned up the surface of the board with a plane and sandpaper. The mast also looks good but did have a slight bend toward the top, fortunately the bend was to the side and this can be corrected once the narrow staves are glued up to the wider staves so this was tackled next.

A straight line was marked along the first wide stave by using a stretched string, I was then able to use this as a base line when gluing the narrow staves to it. A lot of epoxy was needed for this job and much of this was squeezes out, a bit of a waste really but I would rather this than end up with areas with little or no glue. A lot of clamps were required to keep it all in alignment and the designers tip of using packing tape works well. There were a couple of places where I struggles to keep the mast straight so I used a few temporary screws to hold the narrow stave in position while it all set. The screws will be removed and holes filled before the final wide stave is glues in position. The final result is pretty straight mast (or at least three sides of it).

Friday, 14 January 2011

To quote Mr. R Harris “can you tell what it is yet?”

The wood-butcher workshop has had a rather large delivery of materials. Six sheets of Plywood have arrived along with lots of Doug Fir, Western Red Cedar and some White Oak, in fact everything a prospective GIS builder could wish for. I have cheated a little bit and had all the wood pre-machined to the correct size and it took quite some time to check through the delivery to ensure that everything was there. One day I will have the workshop equipment to prepare all the materials myself but until then I have great confidence in Robins Timber to supply what I need planned exactly down to size.

It was actually rather daunting looking at all the virgin materials and thinking where to start; I recall a similar feeling before starting Naughty Note but a lot of sawdust has been swept off the floor since then. I know now that by breaking the build down into lots of easy steps the bigger piece of work soon comes together.

I plan to start by building the hollow mast first followed by foils and centreboard case as these are all items that will be required during the hull build so it makes sense to start with them and not hold up the build later. The boom and yard will probably wait until I am closer to the finish as I have some decisions to make about the sail, how much bend I want in the yard and how I’m going to reef the sail, so there is plenty to mull-over while cracking on with the build.

As before, no time limit has been set for the project, with a young family and sailing events this year spare time will be hard to come by so I doubt it will be launched in 2011. The flip side of this is that the longer the build the more time there is to get the name right, as we all know, that is crucial!

Earlier this week I decided to make a little model of the Goat. As you can see from the pics it is a little “rough and ready” so I should have spent a little more time concentrating on this rather than watching a film but it gives me a nice idea of the shape in 3D and even Mrs Wood-butcher agreed that the GIS has nice lines.

Monday, 10 January 2011

Sailing Naughty Note

The eldest son and I have been out for a sail on Naughty Note this weekend, only her second time on the water! The occasion was a meeting on the UK HBBR (Home Built Boat Rally), numbers attending were a little low as you may expect for a boating rally in January but there were four boats on the water at Dell Quay, Chichester and it was very nice to meet a few of the friendly members.

Initially when setting off on NN I thought I had forgotten how to sail as we crabbed sidewise almost as fast as we were going forward, the daggerboard was down but the leeway was shocking. After a few tacks it started coming back to me and a bit more breeze helped. I found that if you over sheet the sail the boat just seems to stall and slow, I found that keeping the end of the boom just over the corners of the transom gave a good compromise between speed and pointing. A couple of times she struggled to tack until I released the mainsheet, if felt like the CoE was a little too far forward although this was less of a problem when travelling at speed.

I have not changed the setup at all since NN's first sail some time ago and the boat really needs a kicker to control the twist of the sail as when reaching and running the boom goes far to high and a lot of power is lost due to too much twist.

While I was initially disappointed with her performance once I had tuned myself into the boat she was actually good fun and will be a nice stable platform for the boys to learn in. I’m quite keen to try her out in a bit more wind at some point but need step the mast in the front garden and rig a kicker before any more trips out.
Pic taken by Mrs. Wood-Butcher from the warmth of the pub.

Nice link to another blog with pics from yesterday….