Thursday, November 24, 2011

Building the Matinicus Double Ender- Part 9

To view Part 1 click here.

Thanksgiving is traditionally the time that I am able to re-connect with my boat building projects. The sailing season is pretty much done, though I have not put Cricket, my crab skiff, away for the winter quite yet. I look forward to turkey day and the beginning of the holiday season, for the renewed energy and enthusiasm I always feel at the prospect of some real boat carpentry.

Cricket in the marsh, tying in a reef. Photo by Chris Bickford.

 Mouse (as I've named the peapod) has been gathering dust for six busy months of fancy interior cabinetry, including two Manhattan kitchens since July, among other projects. I vacuumed her out and started back in where I left off. The interior had been painted, floorboards were installed, and deck beams were fitted. I screwed in the seat risers, and got out the spanish cedar planks that will make up the thwarts and side benches.

A stack of spanish cedar will become thwarts and side benches.
I made patterns for the thwarts from particle board and scrap 3mm poplar ply. I somehow neglected to photograph this step, but the ply is fitted to the side curvature, and bevels were taken at the fore and aft edges of each thwart. I transferred the patterns to the thwart stock and sawed them out square first, then marked the bevels and sawed to the least angle on the bandsaw, then fine-tuned the bevels with a block plane on the bench.
Bandsawing the bevel on a thwart.
After the thwarts were fitted, I installed hardwood blocks (cherry, in this case) underneath to carry the ends of the side benches. I also added an athwartship stiffener, glued and screwed to the center thwart, because the span at that location is too great to go unsupported. The stiffener is not really visible, unless you look under the seat, and that suits me fine. You'll see a lot of steel screws in these photos. These will all be replaced with bronze, and bunged, before varnishing and installing the furniture permanently. The thwarts will be held in with knees, NOT screwed to the risers. They bear against a frame on one edge, and are captured at the other by the side benches. So, the knees hold them down, and the frames and side benches locate them fore and aft. This is traditional construction. I make patterns for each seat knee from scrap mdf or ply, and fit the notches carefully before laying out and cutting the curve that makes these knees attractive. The knees themselves are cut from straight-grained cherry, with the grain running diagonally from seat to rail.

Patterns are made for the thwart knees.

And the knee is sawn from cherry.
A boat-full of thwarts and knees. The aft knees have not been sawn to shape yet.
A finished knee. The small gaps will close up when the knee is fastened in.
When I planed the thwart stock to final thickness, I left the side bench stock a little thicker. I was worried about having to bend in a stiff plank to the riser's curvature. In retrospect, I probably should have spiled the risers from a wider piece, making them follow a straight line from the aft edge of the center thwart to their aft end. Walt Simmons says this should be a straight line, but I couldn't make my riser stock do anything but follow a curve similar to the sheer curve. It was all I could do to get the risers at the correct height (for rowing) at each location. So consequently, there is a bit of a dip along the span of the benches, in profile. The outside curve in plan view, of course, is just sawn to shape to fit the plank's curvature. So I decided to resaw the bench stock and glue it back together with a little curve in it. I don't know if anyone else does it this way, but it makes sense to me. It took me about thirty minutes to resaw the stock, and run it back through the planer.

Resawing a 12" plank. Piece of cake for this Minimax bandsaw.
An extra high particle board fence is slid over the fence casting to facilitate wide resawing projects.
Dressing the resawn plank to thickness.
 I then set up a simple form with three sticks, the middle of which was higher by the amount of curve I wanted, and glued up a bent plank for each side bench. That's where we are now, on Thanksgivng Day. I will be fitting the side benches next, and finish up the top of the daggerboard case.

Gluing in a slight curve to the side benches.
Ready for side benches.

Stay Tuned!

Sunday, April 3, 2011

Building The Matinicus Double Ender- Part 8

 To view Part 1 click here.

It finally feels like I'm getting somewhere, once the paint starts going on. It provides a temporary welcome relief from the construction, which we'll have to get back to in short order. When we were up at last year's Small Reach Regatta we had a look at Mark Ober's striking Pulsfer Hampton. His cockpit sole was painted a beautiful sand color, and I asked him if it was from Petit paint, and he said he thought it was. I looked at the Petit Easypoxy color chart, and spotted it immediately. Sandtone. I was able to pick all of my colors from the Petit catalog, happily, and ordered the lot from Jamestown Distributors. Easypoxy is a single part polyurethane, similar to Interlux Brightsides, which I've used a lot. Some people advocate painting directly over cured and sanded epoxy with polyurethane paints, but I have always used an appropriate primer which fills small blemishes, and sands beautifully. That is what I did here.

The sanded primer.
Areas to be later bonded to with epoxy are taped off before painting.

I enjoy painting, but it is a lot of work, and somewhat of a marathon. I started on the primer coat one evening about 6:00, and didn't leave the shop until 2:00 am! I was happy the next day that it sanded easily. I then put on three topcoats of Sandtone, sanding in between. The first coat I left gloss, but added a little flattener to the last two coats. Its helps to soften the effect a little, but is not quite as durable as the super high gloss.

The finished interior color.
I did say that I enjoy painting a boat, but the enjoyment is tempered somewhat after going around the boat four times with paint and sandpaper. I can't imagine how someone could get on six or seven coats, though it does get easier as you build up the surface. I keep my boats well covered and protected from the sun, and after four years my crab skiff Cricket still looks great.

I've been hanging on to some salvaged redwood boards for quite a while, thinking I could use them in a boat somewhere, and decided the MDE floor boards would be the perfect use for them. I had a few pieces of dressed 5/4 stock, with a few nail holes from some previous, unknown application (I can't even remember where I got them), and I found an old picnic table top in the dumpster down by my loading dock. I also salvaged a dozen old growth fir 2x4's, vertical grain and virtually clear, from the same dumpster. I've set those aside for a later project, like frames for a dory maybe. I pulled out the floorboard patterns that I had previously made, and laid out the lengths on my redwood stock. I resawed the boards on the bandsaw, then dressed them down to about 7/16". I was concerned that they would be strong enough, but the spans are not over 15", so I think they will be adequate.

The redwood stock is laid out with the floorboard patterns...

...and split open on the bandsaw.

I whittled out about 50 little plugs from the redwood rips, and drove them into any old nail holes that remained after cutting the floorboards out. I love the feel of oiled floorboards under my bare feet. Cricket has a cedar sole that is comfortable, and that I renew with oil every season. I used the old pinetar-linseed oil-turps concoction on Cricket, but I didn't have any on hand in the shop. I did have a bottle of so-called "teak oil", which I put on the redwood, and it is beautiful. The old wood has a lot of character, and looks great in the boat.

The oiled redwood looks pretty against the painted hull.

 I screwed the floorboards down with bronze screws, which will age nicely. Its a good thing the redwood was free, because a box of bronze screws is about $25! So now its on to the rest of the interior, which I've already worked out (see previous post). I'm going to use Spanish cedar for the seats, because of its weight savings. The knees which hold the seats down will be cherry. But more on that later...

Sunday, February 20, 2011

Building The Matinicus Double Ender- Part 7

To view Part 1, click here.

With the boat framed up and the sail plan finalized, it is time to nail down the interior layout. There are two givens; the forward and the aft rowing thwart positions, which I laid out to plan. Starting with these two thwarts, I drew up the deck plan and furniture arrangement.

Deck plan and interior arrangement.

I've always known I would deck the boat. Washboards (side decks) and coamings do a wonderful job of keeping the water out, and will allow us to sail the boat a little harder than we might with open gunwales. On the other hand, a large deck area can choke up the interior, particularly if side benches are to be fitted, as I am doing here. I had initially intended to step the main mast through the deck, but after thinking about this, I decided to keep the end decks short, and step the main mast through a thwart. This would allow me to fit a mast gate so that I might more easily step or ship the mast afloat. The heel of the mast is set into the step mortise, and the mast is pushed upright through the open gate. Once in position, a heavy pin will be slid into place behind the mast, closing the gate. This is all quite a bit easier than standing up with a mast held high, and trying to get it down through a hole in the deck and into the mortise in the step, with the boat rolling and pitching to boot. The substantial lever of a flailing mast can tear up the whole front end of the boat! So I laid out the deck to stop just short of the mast forward. The mizzen, being  a much smaller and lighter stick, will pass through the aft deck.

I cut the main mast step from more of my dumpster fir, notching it around the stem knee and butting up tight against the forward frame. The mizzen step sits right on top of the aft stem. I glued and screwed the steps down with epoxy and bronze screws.

The main mast step notches around the stem knee...

...while the mizzen step sits on top.

Next, I got set up to fit the seat risers. At the forward thwart location, I leveled across to the side of the boat from the dagger trunk (I double-checked that the boat itself was still level athwartship). I tacked battens in the boat port and starboard, temporarily nailing these into the frames when they were pulled up level. To make this easier to do, I cut out temporary flake board thwarts, resting each end on the riser battens with a spirit level on top (I'll use these later to make patterns for the real thwarts).

Leveling the riser battens.

 At the aft rowing thwart, I nailed the battens in a set distance below the sheer (at proper rowing height), again leveling across the boat. I then hauled the battens into place at both ends of the boat, pulling the forward end as high as I could to maximize the bury of the mast (the mast partner rests on the risers). This all took quite a bit of fiddling to get right. There is a lot of twist in the riser, and the battens don't want to lay flat on the frames, compounding the difficulty of accurately determining the correct height. I was afraid the risers themselves would be hard to bend into the boat, but they were relatively easy to get in, and I clamped, then screwed them without glue to the frames at the correct height. They will be removed again to paint the interior, then re-hung with glue later. Finally, I fitted the aft most thwart pattern, set just forward of the end deck, and some rough approximations of the side benches.

The 'midship side benches are quite long, so I fitted a knee in the middle of their span, to help support them. With these all in place, I was really able to get a feel for the interior structure of the boat, and I like it! There are plenty of seating options available to trim the boat, depending on crew. The push-pull tiller will have a screw-on extension for solo sailing, allowing me to move close to the middle of the boat. It can be removed for the skipper to slide aft when more crew come aboard. I have to say that I quite like this type of steering, having used it for years in my sailing canoes.

The actual seat risers are fitted, and knees are added to support the side benches at mid-span.

Close up view of the side bench knee and riser.

Now, its on to the deck beams. Once the extent of the end decking was known, I installed the full length beams in the end of the boat. I glued little short blocks to the inwale, to which I would glue and screw these frames. The frames could also be let into the inwales, but I chose not to do it that way. The compound bevels on the beam ends were cut quickly with a hand saw. I left the beams wide until they fit snugly, and were screwed in place. I then scribed them to the deck camber with a template, removed them and cut them to shape, and glued them back in permanently.

Deck beams are fitted, then marked out to the camber and cut out.

The little short washboard beams, or knees if you prefer, were a little trickier to fit, notching over the inwale and extending down along the inside of the sheer plank a couple of inches. This shape gives them enough strength, when glued and screwed to the frames, to stand alone without angle braces of any sort. Like the full length beams, I left them over size and temporarily screwed them all to the boat. To determine their exact length, I sprung in a batten from end to end, terminating at the full length end deck beams. At the same time, I put in thin ply template stock at each end, and bent a drafting spline to the shape of the oval deck ends, fairing this into the batten. This gave me the exact shape of the complete deck.

Carlin batten and oval coaming template.

I marked all of the knees, then removed them and laid out their shapes. There is a longitudinal timber called a carlin, which defines the outer cockpit edge and supports the decking, much like the inwale does out at the sheer. I like to rest the carlin in a notch cut into the knees. I cut this notch in each knee, using the layout line that I marked from the batten. I then marked and cut a curve in the underside of each knee. When the knees were all cut, I glued and screwed them into the boat.

The deck knees are all glued in.

Knees are notched for the carlins.

Before going any further, I need to stop and paint the interior. Any other structure in the boat will make it too hard to paint around. The carlins in particular would be in the way, and I'll also wait on the oval deck framing and the king planks for the same reason. I can't wait to paint the inside!

Sunday, January 9, 2011

Building The Matinicus Double Ender- Part 6

The lug yawl sail plan is finalized .

Its hard to believe that almost a year has passed since the last post. Once spring comes around, there is so much work to do at the club in preparation for the sailing season, and then the season itself (which this year continued on until nearly Thanksgiving). Six months go by without any progress on the peapod! And so I look forward to the holidays as a time to re-connect with boat building.I had always intended to rig this boat as a lug yawl, and finally got around to drawing up the sail plan. I also decided to substitute a dagger board for the pivoting centerboard. The dagger board is lighter, simpler, and takes up less space than a centerboard, and when rowing, a plug can be dropped in the slot to eliminate speed robbing turbulence in the trunk. This conversion is not as simple as it might seem, as any changes to rig or underbody can affect the balance of the boat, producing a heavier than normal weather helm, or a possibly dangerous lee helm. The thwart layout and rowing positions determine, to some extent, the position of the dagger trunk, as thwart and trunk are mutually supportive structurally. Once the balance point of the hull is arrived at (by balancing a scaled cutout of the underbody on an awl and marking the point), the rig is drawn and its geometric center is found. I played around with mast placement, rake, sail shape, etc. and made many back and forth adjustments with the sails and the dagger board until I arrived at what I hope will be a well balanced boat.

So its on to the interior! I built the dagger trunk first, and made it a good four inches longer fore and aft than the board itself, still hedging my bets as regards the balance until the sailing trials. I'll fill in the excess slot once I determine the exact position of the board. The trunk is so simple! Just two posts, which extend through the plank keel, two sides, and two bed logs cut to the slight curve of the inside bottom.
The completed trunk, upside down. The posts will extend through the keel.
Slot pattern for a long top-bearing router bit.
 I made a router jig to cut the slot from inside the boat, and I left the ends of the slot plumb even though the posts are raked to avoid chiseling the angles through 1-1/2" of keel. A wedge will be epoxied in (one from inside, one from outside) to close up the gap. Very simple.

A wedge will be epoxied in to fill the gap.

I blue-taped the parts of the slot that must remain clean, and then glued and clamped the trunk into the boat, being careful to keep it plumb athwartship.

The area of the slot to remain clean is masked off.

The trunk is clamped to the boat through the slot.

The frames are next, and I chose to use a futtock style frame of spanish cedar, glued up in halves with short pieces to optimize grain direction. I settled on 5 frames, built to span sheer to sheer and set perpendicular to the centerline like a bulkhead, and joggled to fit the laps.

The first layer of the spanish cedar frame-halves.

Layer two spans the previous butt-joints.
 I'll confess right up front that the bevels eluded me. It would have been much simpler to set the frames square to the planking, but I wanted a continuous frame, dory style, and so paid the price. My method of finding the frame shapes is quite simple, and avoids spiling. I cut a scrap of thin (1/8") ply close to the inside shape, but ignoring the laps. I then hot-glued a few small blocks in the hull, and tack welded the rough pattern to the blocks with more hot glue.

A thin ply pattern is hot-glued to small blocks exactly in the frames intended location.
 I next ripped up strips of the same thin ply, cut them to length, and hot-glued them to the pattern board at each plank. This is very fast, and extremely accurate. As long as the pattern is set exactly where you want the frame to land, then the frame will fit every time.

Straight-edged strips fit snugly to the planks.

The shape is traced onto the glued-up frame blank, and sawn out.
 I use the same pattern for both sides of the hull, but I do try it out on the other side and make notes of any slight discrepancies. Now for those tricky bevels. I cut the frames square, tight on one edge, but leaving a gap at the other.

The frame fits tight on one edge, bust is open in way of the bevels.
 I ripped up a pile of variously beveled strips on the bandsaw, and used this stock to add the bevels to the frame, rather than cutting the bevels away. I release-taped the hull under each frame half, and glued these bevels to the frame halves right in the boat.

Beveled wedges are glued in.
 When the glue cured, I removed the frames and cleaned everything up, before installing the frames permanently in the boat. The end result is structurally identical to a sawn bevel, even if the method is somewhat unorthodox. I will admit to being a trifle sheepish about it, but I'm quite satisfied with the end result. The frame halves are connected together across the bottom with a final piece, then the inside curve is sawn to shape and beveled in one piece before installing in the boat. Don't forget to cut the limbers!!

Before the frames are glued in, the hull is taped off for easy clean up.
The frame spans are too large to adequately support a 3/8" thick floor board, so I fitted short floors (timbers) between each frame. I went ahead and made patterns for all the floorboards while I was at it. The floors were glued in just like the frames.

Floor board patterns were made at the same time as the timbers.
A finished floor timber, ready to install (note the limbers).
Floor timbers are glued into the boat. This completes the framing!
I installed the sheer clamps (inwales) after the frames, notching the frame heads before they went in the boat.

The inwales (sheer clamps) are scarfed to length.
 I scarfed up a plank of spanish cedar to length, ripped out the pair, and fitted them to the boat. I did this by myself, and it is a bit tricky with epoxy all over a 16 foot long noodle which gets surprisingly stiff and contrary when forced into a deep compound bend. But it worked out well. The notched frame heads really help hold the timber in place.

Inwales are clamped to the sheer. It takes a lot of clamps!
 There are no breasthooks in this boat. She will be half decked, with an oval coaming. I like to fit a longitudinal beam (like a deck king plank) let into the deck beams and going all the way to the stems, taking the place of a breasthook, and strengthening the centerline. This longitudinal beam can also double as a mast partner like on my crab skiff Cricket.

Different boat! This shows the deck framing I like to use on Cricket.
We'll end here for now. I'm working on the final deck and furniture plan now, and fitting the seat risers. By next time, the interior should be shaping up well. Stay tuned...