Measure twice, then again, and again

This past weekend was nice and busy, occupied with gardening, going out for beer and wine tastings and dim sum, barbecuing, wine and other shopping and other things; I am not a boatbuilding obsessive.  Still, I spent several hours drawing the frames on 9mm plywood.  Armed with a T-square, metal ruler, tape measure and protractor, I measured, marked, drew, checked, added, subtracted, compared with printouts, erased, and so on.  Each piece has eight sides on the bottom alone, so it takes about 34 measurements (half vertical, half horizontal) to draw, plus a pencil tied to a piece of string for the curved bits.  Not too many early mistakes, and I hope none left uncaught, plus I got quicker at it as time went by.  It took a few more hours on two weekday evenings to finish and double-check the drawing.  The final check involved using the Pythagorean theorem: believe it or not, this stuff is actually useful.  I had coordinates for the beginning- and end-point of each straight side, so I calculated the vertical and horizontal distance between them, squared them, added them and took the square root (the old a^2+b^2=c^2 formula).  Thank heavens for Excel.  The biggest error was 3mm, about one-eighth of an inch (I blame fat pencil tips and fat fingers), and I fixed it anyway.

Cutting the pieces will be tough, with so many straight sides.  Some can be done with a circular saw; others will take a jigsaw, with drill holes at the corners so I can change directions.  When all eight are cut, I will line them up and take a photo to post here.  It's almost Easter weekend, and both my daughters are home from grad school (yes, I am that old), so I won't be doing much cutting--not that I'm complaining, it's a great joy to have them around.  I have a feeling building this boat will take a long time!

Plywood Pallets and Cowboys

The plywood and the oak arrived today at lunchtime.  It being a workday, I rode my bike home to meet the truck.  The driver was a small but extremely wiry gentleman, with a weatherbeaten face and a bandy-legged gait, wearing well-worn leather chaps, a cowboy hat and a belt buckle the size of a serving platter.  Turns out he was a retired cowboy.  He had to drag a large pallet from the truck to the back alley so we could put it in the detached garage, using a hand-operated hydraulic forklift.  Since the end of the pallet dragged on the ground, I helped by putting a two-wheeled dolly under that end, standing on the dolly on my left foot and pulling on it to keep the pallet from dragging, and pushing with my right foot while madly hopping along like Hopalong Cassidy.  I wish I had some video--I'm sure we must have looked hilarious.

Anyway, after getting the pallet (which was built to withstand all manner of natural and man-made disasters) into the garage I had to take it apart to inspect the merchandise.  I did and offered the cowboy gentleman a tip, which he adamantly refused with great dignity.  This was the kind of guy I wouldn't mind sharing some whiskey with in some saloon somewhere.  I then wolfed down some leftovers and cycled back to work. 

So tomorrow will mark the first day of actual boatbuilding.  I'd better measure twice or thrice and cut once, as they say.  Wish me luck.

For more adventures in boatbuilding, keep reading 176inches.

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Materials and planning

Hello faithful readers!  Here's the Robin, my old boat, before the centerboard got stuck and the tiller came off, on the other side of the lagoon you see in the background (read the first couple of posts for the history).  I've learned a lot since then--but at least I was younger and thinner...  Shallow little thing she is, with seats flush with the gunwales.  Obviously one gets quite wet in rough weather.  She also has a simple, angular cross-section.  The new boat will be deeper, with seats well below the gunwales, side decks with splash guards, etc.  It will also have a more complex, rounded form and old-timey lines from the overlapping boards.

I ordered the plywood and oak boards from Homestead Hardwoods in Vickery, OH.  Three 9mm thick 4x8 foot boards for the transverse pieces (frames, transom and bulkheads), and nine 6mm thick 4x8s for everything else.  I think I only need 8 sheets of the 6mm plywood, but it's good to have a spare, given the high cost of shipping.  The oak is mainly for the keel, bow and rubrails, places that will be scraping against rocks, sand and docks (hopefully not other boats!).  By far the largest expense for the whole project, this purchase pushed the total cost so far to just over $1,000.  I have all I need for the hull (except paint), and there will be more expenses for lumber for the spars (masts, yards and booms), sailcloth and related supplies, and chandlery items (that's marine hardware, etc.)  The marine hardware will be things like blocks (pulleys to you landlubbers), line (rope to you), cleats, fairleads, deadyes, snaphooks, etc.  Oh yes, and the lead.  People may wonder why I will be buying 100 pounds of lead shot, since I don't own a shotgun. I will need it for ballast (for stability), and the rudder and centerboard so they can drop into the water when they are not hoisted up. Both need to be retractable for launching and recovery, and when in very shallow water.  But all that will come later.  I have to build the hull first.  By the time I'm done I expect to spend a total of somewhere between $1,500 and $2,000.  That's not counting my labor of course!

The way it will proceed is:

• Cut the transverse pieces and a bow brace first.  
• Assemble the fore-end, joining together the two forward bulkheads and bow brace.
• Build the centerboard case.
• Cut the bench risers, with slots for the frames.  
• Lay the bench risers on the building frame; fit and attach all transverse pieces and the centerboard case.
• Attach the keelson (a 1X4 inch board along the whole length of the bottom of the boat).
• Then I'll be almost ready for the long hull pieces, otherwise known as strakes.  The first (since the boat is built upside-down) are the bottom pieces, otherwise known as garboards.  

But that's enough for now.  For more about the project, check in again at 176inches.

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Getting Started

Things are starting to move beyond pencil and paper.  Three days ago I received my first shipment: epoxy, nails and screws and a few other bits.  Epoxy of course is ideal for boats because it is very strong and a totally waterproof coating.  Old-fashioned purists will argue in favor of other glues and coatings but I'll go with what I know.  The nails and screws are made of silicon bronze: pricey these days but will not corrode, even in sea-water, which this boat may end up bathing in: witness ancient bronze statues found on the bottom of the sea.  I hear that stainless steel is not as resistant, and in any case it will rust if it's not exposed to the air, which rules it out for boatbuilding, except for fastening bits of hardware on the deck and spars.

Th epoxy is for gluing things together, and also for coating all the wooden parts with two coats before the paint or the varnish.  Speaking of that, I intend to paint the bottom royal blue and the fore- and side-decks white.  I have sought the advice of my wife and daughters, and they agree.  It will be a nod to the national colors of Greece, and consequently the boat will have to have a Greek name.  Ideas welcome!

Yesterday my wife Robin and I cleaned out the garage and, with some regret, banished the old boat Robin outside,  She was named that, at my daughter Georgia's brilliant suggestion, partly because it is red and brown, partly after my wife, who was peeved at me at the time for being a "boatbuilding widow."  Here's the Robin leaning against the garage wall.

Yesterday I also bought some cedar boards for things like the keelson, srtingers, cleats and beams, all fancy words for lumber that the plywood pieces will be glued to in places other than the overlapped edges of their neighbors (the "lapstrake" bit).  Bear with me, you'll learn all these terms if you keep reading 176inches.  I also got a couple of wheels and a couple of 2x4s.  The result was the building frame, which can be rolled in and out of the garage.  Here it is on the left.

For more boatbuilding sweat, blood and tears (only kidding, at least for now) keep checking 176 inches.

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Design quirks

A bit more about the design and planned building method:

The Carlson hull design software builds up a hull over four polygonal (straight-sided) transverse bulkheads, including the transom.  It gives the dimensions and coordinates of these plus other frames specified by the user.  I divided the 176 inches into 8 sections of 22 inches each, so I have coordinates for 8 frames.  The program also calculates the flat profiles of the strakes that wrap around the frames, and allows you to place the pieces on 4x8 sheets, giving visual printouts and coordinates.

Here's the standard three-view as created by the software.  As you can see it has the basic outlines, without seating, decking, floor, thwart, skeg or anything else.  The rest needed some work.

There were many more things to figure out, such as the shapes and sizes of the bench risers, seats and skeg, the depth of the floor, the angles and overlaps between strakes, etc.  I worked all that out by plugging  coordinates into Excel and working out formulas.  High school trigonometry helped a lot!  I also converted everything to millimeters just in case--Excel does not like fractions and 5.81 inches is hard to measure.

Because the program assumes carvel-built design (with the strakes flush against each other), I have to add enough extra width to the strakes so they can be beveled and glued together.  I will have to bevel the plywood (after scarfing pieces together--more on that later) using hand planes I bought cheap at an antique store.  I plan to use epoxy and bronze ring-shank nails that will be set (recessed) and clenched on the inside, then the indentations filled before painting.

I also had to figure out some basics about the centerboard and the sails, to make sure everything fit around the frames, decks, etc., and that the centerboard and sail placement was correct for a balanced helm, not only for the chosen rig but for the three alternatives. It all took a fair amount of pencil-and-ruler-on-paper work.  I will post a more detailed drawing of the design with the extra features, but it will take some time because my pencil sketches need detailing and prettying up.

Next time, a few more design details.

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Design Choices

What went into the design you say?  Well, it was meant to be an open boat, about 15 feet, with plenty of stability and freeboard, and pretty dry in a chop.  It needed to be a capable sailer (including single-handed sailing) and easy to row.  Preferably it would look old-timey, but not be impossibly hard to build.  I would have a short unstayed mast or two, but the rig would be flexible.  It would have adequate storage, plus extra buoyancy in case of swamping or capsizing.  The oars had to be stowable out of sight, and the floor had to be flat.

That's a pretty complicated combination.  What I settled on was a lapstrake design (nice and traditional looking) with a V-bottom (ditto, and less slappy on the waves), with four strakes per side (easier to build but still nicely rounded), built around a total of eight frames, including transom and two full-size bulkheads.  Unlike regular lapstrake forms, the frames will be permanent and will increase rigidity.  The boat will have side benches all the way from transom to main forward bulkhead, with storage and buoyancy built into them, and large storage lockers fore and aft.  It will have a foredeck and side decks for dryness, and a removable plank floor with room under it for oar stowage and lead shot ballast in a special compartment.

The hull will be built upside-down over two sturdy sawhorses, connected with wooden runners on wheels, so the whole thing can be moved in and out of my small, unheated garage.  Most of the work will have to be done in the warm season, because epoxy doesn't cure in the cold.  The vertical risers of the side benches will sit on top of the saw horses, and the frames and bulkheads will interlock with them like three-dimensional puzzle pieces. 

The other decision to be made was the rig.  At first I thought that it should be switchable from cat to sloop, the latter with a jib and a bowsprit.  But that would have meant a tall mast, which I dislike.  I then considered a yawl rig, which I rejected for various reasons.  The chosen rig was a cat ketch with a balanced lug main and a standing lug/ sprit boom mizzen.  For more on all these old-timers, you could read David Nichols's book.  Still, there will be four different possible mast steps that can accommodate all four possible rigs.  I like the cat ketch design, because it is stable, has two smaller and more manageable sails, and is very easy to tack and to sail single-handed.  It also means that a mast hole goes through the rowing thwart, and the centerboard case has to be slightly off center.

So there you have it.  Next time I'll talk about the mechanics of the design and planned building techniques.

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Some history II

Anyway, I was talking about a sliding Gunter (BTW, it does get a little arcane, but Wikipedia and Google are great for explanations for those who need them).

That wasn't the end. In search of an ever better rig, I replaced the regular boom with a sprit boom. I finally decided I didn't want to mess with either the jib (too small to matter, too picky for single-handed sailing), or with stays  So I modified the sail to a bat-wing with full-length battens, and replaced the 14 foot mast with a 10'8" unstayed one.  This final rig served me well for a while.

Then we moved to Ohio, and the little boat was fine for the city reservoir, but too small to risk on lake Erie, where big waves can come out of nowhere. A one-mile-square reservoir gets a little repetitive, even though it has plenty of wind, being 20 feet above ground level.  I got bored and decided to build a bigger boat, still small enough to fit on the small trailer, but with side decks, more freeboard and more stability.

I shopped around for plans, but I couldn't decide on what I wanted.  None seemed to have the right combination of features, size, versatility, old-timey look, relative ease of building, etc.  I had already figured out from experience that plans may need a lot of tinkering, or may be poor designs (especially after building an unbelievably tippy plywood canoe, whose designer shall remain nameless, for fear of possible lawsuits :-)).  Being a fearless tinkerer, I decided to look for ways to design my own.

My inspiration came from many fine naval architects, and I owe a debt for ideas especially to Francois Vivier, John Welsford, and B&B Yacht Designs.  I used the free hull design program from Carlson Design to test my ideas and come up with dimensions and shapes of bulkheads, frames and strake panels.  For more of what went into the design choices, check the next installment of 176Inches.

boatbuilder