Monday, July 26, 2010

Chinese Junk Rig Sail

The plans for Featherwind allow for a Sunfish sail and also include a sail plan for a lanteen sail of different dimensions than the Sunfish sail. The Chinese junk rig sail is what really grabbed me though so I'm going to give it a try. I'm building my sail from plans for a 78 square foot junk rig sail found on Duckworks magazine website which is about the same square footage as the Sunfish sail. Since the junk rig sail is easily reefed, I added an extra panel at the bottom of the sail for a total sail area of 94 square feet so when the wind is very light I'll have some "extra" sail I can hoist. The photo shows the 16X10 or so white poly tarp that I cut my sail out of. In this photo the sail has been cut out and is surrounded by the left over tarp.


The sail plan calls for a dart to be sewn into the luff and leech for each batten. The luff is the side of the sail that is attached to the mast and the leech is the side of the sail opposite of the luff . The darts will give each panel, (the sail area between the battens), a concave shape and this is desirable as it improves performance over that of a flat sail. The final photo below shows a view of panels and battens. This photo attempts to show the darts drawn on the sail.


This photo is a close up of a couple of darts drawn on the sail. The horizontal line marks where the gurney flap will be located. The gurney flap is part of the sail that extends past the battens on the leech of the sail. It's five inches wide and tapers off to zero towards the upper part of the sail. The gurney flap is said to improve windward performance of the junk rig sail.


Once the sail is cut out and the darts are sewn in, one needs to sew nylon pac cloth to the leech and luff. Six hundred denier nylon pac cloth is a tough sturdy material and is what I used. I have to say thanks to my ma for doing the sewing for me on her sewing machine. The sail needs to have the pac cloth sewn to the leech and luff because when you hoist the sail the poly tarp alone wouldn't be able to take the stress from the weight of the battens. This photo shows pac cloth sewn onto the poly tarp. In the foreground is the top of the sail. On the right is the leech with pac cloth and on the left is the luff with pac cloth. The sail seems very sail like even though it's polytarp.

This photo shows a close up of a d ring. The D ring shown in the photo is sewn to the gurney flap in line with a batten. There is a D ring for each of the five lowest battens and a rope is attached to each D ring so the sail can be can be trimmed to different points of sail.


Now I have a sail with darts, pac cloth sewn on the luff and leech, and D rings attached to the gurney flap. Now I have to add the battens to the sail. The battens are attached to the sail in pairs by screwing the battens together with the sail sandwiched in between. This photo shows the wood pieces for the battens and yard right after I cut them from a larger piece of wood. I painted them the same chocolate color as the mast.


Finally I get to raise the sail and have a look.



















Bamboo Floor

The plans for Featherwind do not include building seats or a floor as it is a very simple light weight boat. I'm good with sitting on the floor and I like the space that is left available by not putting seats in. But I do remember sitting on the floor of a canoe and not liking it very much when some water would come aboard. So I decided to attempt to add a floor to this boat. The simplest light weight solution I could come up with is a bamboo floor. I think that the bamboo also adds to the Chinese junk theme I'm doing and I like the appearance of it. The floor is removable for cleaning or if it turns out I don't like this floor after all. This photo shows a view of the bamboo pieces laid out in the hull on top of the frames to get an idea of how it's going to look.


The bamboo comes from a roll of bamboo fencing purchased at a national chain store. This was the cheapest bamboo I could find and it comes in a four foot length which is just about perfect. My idea is to have the ends of the bamboo sit on top of the three frame pieces. This gets my butt off the hull bottom by a couple of inches and should keep me dry when a little water splashes in as the water will be below the bamboo. The diameter of the bamboo varies from piece to piece but is an inch or more in diameter. It's pretty strong and doesn't bend very much. The floor is in two sections, a front floor and a back floor. The bamboo's four foot length works perfect for the front floor but is just a tad shy in length for the back floor. I added a piece of wood or a ledge to the back frame to solve this. This photo is of that ledge on the back frame. I attached it with epoxy because I didn't want to drill holes in the frame to attach it with screws. It did support my weight, so far so good.

I also had to add two small ledges on the port and starboard side of the mid frame where the gussets are located as the gussets interfere with the bamboo resting on the frame. Hopefully the picture explains this better than the verbal. Here is a view of my two mini ledges. By adding the two pieces of wood I now have surface on both sides of the gussets for the bamboo to rest on.


Here's photo of the completed front floor. Besides the four foot lengths of bamboo I also used cross pieces of bamboo to reinforce the floor. Doing this felt like it added a lot of strength and stiffness to the floor. It's all tied together with light weight rope like a raft. The front floor fits nicely around the mast base.


Here's a photo of both floors completed. You may notice that the floors do not go all the way to the sides of the hull. I intend to add cushions to that space and decided running the bamboo all the way out to the sides is not needed. By the way, I don't actually plan to sit on the bamboo but instead on a flotation cushion or some other more comfortable arrangement.


This photo shows how the bamboo floors are attached to the boat. They are tied to the hull with a piece of rope at each corner of the floor section. To remove the floor I would only need to untie the ropes that hold them in place. The rope goes through the limber hole in the frame and around the bamboo. No problems with this arrangement so far.

Wednesday, July 21, 2010

Mast

I was pondering what to do about a mast. I thought it would be cool to attempt to build a hollow birdsmouth mast. It also seemed like it might be a bit of a project to build one. While I was pondering this I searched on Craigslist and found a hollow wooden mast offered for free. I'm in the state of FL and the mast was located in IL. Fantastically enough my mother was visiting IL and was near the mast. I got my ma to pick up the mast and put it on the roof rack of her SUV and bring it back to FL when she returned from visiting. I figure with this kind of luck I should be able to win the lotto. So here's a pic of the mast packaged as it arrived with the boom and stay wires duct taped on.

The mast is about nineteen feet long and about four inches across at the base. I removed the sail track and stay wires that were attached to it and sanded it down. It had some old varnish on it which had mostly flaked off so getting down to bare wood wasn't much of a problem. The original Bolger plan for this boat shows a sloop rig with a mast about this long so I figure this mast could be fine for this boat. After I get my junk rig sail built I'll see if I can reduce the length of the mast.


Here's a pic of the painted mast. I went with a chocolate brown color which matches the color of the dragon head I'm going to mount to the bow. Going to use the same color on the yard and battens.












This pic shows two pieces of brass hardware that were also given to me with the mast. The brass piece attached to the mast base fits onto the brass mast step that is attached to the boat.










This pic shows the mast in place. Stepping the mast by myself, that is putting the mast into the boat, is no problem due to the light weight of the mast. I'm very happy that this mast is easy to handle.




I'm going to try to get away with out using stay wires on the mast. We'll see how it goes. Here's a pic from a distance of the boat with mast. Shiver me timbers!