Sunday, May 29, 2011

Garboard

This being a long weekend and my wife being away to take care of her sick mother, I thought I'd try to make a lot of progress.  So I am happy to report some.  I put on the keelson and then beveled it to take the bottom pieces.  I call them garboards, which is the common term for the first pieces (next to the keel) that go on when building a lapstrake boat upside down, but I wonder if that applies to a design with only four strakes per side.  Beveling a 13 foot 1X4 board to an 8 degree angle takes a lot of planing and sanding, and as you can see the garage looks like a nest of pet rabbits from the shavings.  Another look of the keelson and the centrerboard case on the right.


















Then I took the plunge and cut the garboards (aka Strake 1).  I did not trust the design program and/or my own measuring and cutting skills, so I decided not to join two 4X8 plywood sheets, then cut the pieces (not enough room anyway).  So I cut the two halves separately, fit them (they were fine), then scarfed them.  I have to say that sanding is very far from my favorite activity, so I did not enjoy the scarfing, nor was it a particularly good job, but it will do (see on left).

So today was the time to commit to glue and nails.  First I had to cut a slot for the centerboard, which turned out surprisingly easy (even though I had to set the blade of the circular saw at 8 degrees).  Then I coated surfaces with epoxy, mixed more epoxy with wood flour, slathered the goo on all the joints, and nailed on the garboards, using bronze ringshank nails.  I will have to set the nails and putty the indentations, but for now let's admire the putative boat, which is looking more like a boat every day.  See also the close-up of the bottom, with the off-center centerboard slot.

By the way, if I hadn't forgotten what a pain it is working with epoxy (sticky, messy, ruins brushes, coats tools, needs a respirator which is hot, sweaty and awkward, leaves black rings around fingernails, etc.) maybe I wouldn't have started.  But now I am committed, so keep reading 176inches.

boatbuilder

Sunday, May 22, 2011

Frame assembly

This past week was very productive.  The entire skeleton of the boat is basically ready.  There it is on the right.  I started with a lot of cutting and joining.  I ripped inwales and seat stringers (tricky angles) and scarfed them together to a full sixteen feet.  I also scarfed together the keelson.  I cut a seat stringer for the transom (extra tricky, since the transom is not vertical).  Then I butt-joined the seat risers that serve as a vertical frame.  I cut round holes for inspection ports in the middle of what will be buoyancy chambers.  I glued cleats along three of their sides, and cut notches in the fourth for the transverse frames.  All this gluing went well.  I test fit everything many times.  Then I nailed the risers to the sawhorses to make sure everything stayed square and level. 

Then came the time for more gluing.  The day was very hot, and the behavior of the epoxy took me by surprise, although I should have known better.  While I was trying to attach the transom (it was messy, fighting gravity the whole time), the first batch of mixed epoxy turned very hot and solidified in no time.  You see, epoxy resin and hardener mix in an exothermic reaction, the heat of which needs to dissipate.  On a hot day it doesn't happen.  So with the next batch I put the measuring cup in a bowl of ice-water and it worked a charm.  Anyway, the fore-end assembly and the transom are on, the centerboard case is attached, and some of the frames (first and third forward of the transom) have cleats glued on that strengthen their joint with the seat risers.

All this time I was working with a respirator on, because my daughter the sculptor kept insisting (she has worked with all kinds of toxic stuff) and I kept getting throat irritation every time I used epoxy anyway.  That was fine, but on a hot day it gets sweaty, the glasses get in the way, etc.  The final ignominy was that I got some epoxy in my hair, and it was very hard to remove.

Another problem came from working alone.  Attaching the centerboard case (which is pretty heavy) to two frames was very difficult.  Trying to put screws into oak requires pilot holes of perfect length and diameter, or the screws break or strip.  Got it done, though.  

The next step is to strengthen the frame-riser joints with epoxy fillets and short cleats, and put on the keelson, which I have test-fitted already.  Then, once I bevel the keelson, I will be ready to start putting on the boat's "skin".  More fun and games, starting with scarfing together plywood sheets into 16x4 foot pieces, measuring and cutting etc.

Till next time,
boatbuilder

Saturday, May 14, 2011

Starting assembly

 Well, assembly has started (finally).  This is the bow, laminated from two layers of 9mm (3/8 inch) plywood, and the two fore bulkheads.  They are nailed and glued (with some temporary screws) to a horizontal beam that will have the mainmast hole forward of the first bulkhead.  There is also a temporary brace to hold the two bulkheads together until the keelson and inwales go on.  You can see that each bulkhead has a cedar doubler for strength and for nailing the foredeck on (much later, when the hull is built and the boat is flipped right-side-up).  The tops of the bulkheads will be rounded before that, but for now it's convenient to have straight tops to keep everything square and level, especially since the centerline of the fore-end beam is designed to be exactly horizontal.  You can also see the square opening in the main bulkhead, which will have a sliding panel for access to a large locker. The bow is angular for now, but will be rounded after the hull is built, with the addition of oak pieces.

The fore-end assembly sits on the pallet that the plywood arrived in (see Pallets and Cowboys).  Unfortunately it is a little warped and I had to make adjustments.  This pallet is a convenient size for plywood cuts and minor assembly, but the fact that I have to use it is testament to my lack of space.  I also lack tabletop space (hard to fit a table of any kind amid the gardening supplies and equipment), so the tools are all over the place and I have to tidy up periodically. 

On the right you can see all the components of the centerboard (CB) case, ready to assemble (after a second coat of epoxy on the inside).  On top is the starboard panel seen from the outside.  You can see a cleat on the top edge for strength and to glue a plywood strip (with a slot for the CB).  The bottom doubler will attach to the hull--you  can see how it was curved to fit the curvature of the boat's bottom. It will be below the floorboards.  Of course these doublers and the panels themselves had to be cut to different sizes and glued at different heights to fit around the keelson and account for the v-shape of the boat's bottom.  Once again, thank heavens for trigonometry.

Below you see the inside of the port panel of the CB case, with 7/8-inch thick oak spacers to accommodate a 3/4-inch CB.  You can also see a mock CB for fitting purposes, cut out of corrugated cardboard (it held my wife's new laptop computer).  The extra-long spacer on the left will provide support for the rowing thwart/mizzen mast step, as well as a place to put hardware for CB haul line and mainsheet.  I cut it too long so I can adjust it as needed.

Today reminded me how messy epoxy is to work with, especially the mixture thickened with wood flour.  Gloves are of little help, and hands and tools have to be cleaned every time.  The boatbuilder's best friend, white distilled vinegar, works like a charm, BTW.  As for the inevitable spills, I'm not too worried since the garage floor is coated with epoxy anyway!

To see more progress and pictures, keep reading 176inches.

boatbuilder

Sunday, May 8, 2011

Cuts and more cuts

I did put in a day's work last Sunday.  Frustratingly, I spent a long time on a dust box made of particleboard, but the underside of the table saw is complicated, the fit is not too good and the contraption picks up some but not all particles of sawdust.  I suppose I need to tinker with it a little.  I also drew and cut the seat risers and the centerboard (CB) case sides and ripped some lumber into cleats.

This weekend I cut all the pieces for the CB case.  I need to assemble it before I lay out all the frames along the seat risers, because it will connect the three middle frames and stiffen the whole structure.  The centerboard itself I will make later, out of three layers of 6mm (1/4 inch) plywood glued together.  The middle piece will have a hole cut out to be filled with lead shot, and sandwiched in between two solid pieces.  This means that I had to draw and cut a mock centerboard out of thick cardboard, to make sure it pivots properly in the CB case.  That's one of a myriad bits of extra calculation and work that comes with a home-made one-of-a-kind design.  Before I put together the CB case, I will have to give the inside two coats of epoxy.

I also cut doublers for the tops of the two fore bulkheads, and the beam that connects the bow to them.  Finally, I cut a 13-inch-square opening in the main fore bulkhead: it will have a sliding door, opening onto a storage locker.  In coming days I will epoxy and assemble the CB case; laminate the two layers of the bow together; glue the doublers to the tops of the fore bulkheads and assemble the whole fore-end (two bulkheads and bow);  and butt-join the parts of the seat risers together.  Promises, promises, I know, but the work is slower than I had hoped.  I thought it best to do all the cutting I could before I started using epoxy: it's messy work, and I have to throw away the brush after less than an hour anyway, when it succumbs to rigor mortis so to speak, so it's a good idea to do as much as possible at the same time.  Plus I needed to clean up the sawdust lest it sticks to epoxied surfaces.  That I have done, so I'm ready for the sticky stuff.  Next time there will be some photos too.

So please come back to 176inches.

boatbuilder