My Backyard Boats:

Archive of On Deck log entries: 24 July 03

First the Flats Rat, now the ArcAngel

[Read the original, tone-setting post to this log]

Free plans here.

 

    28 September 03: I began working a few weeks ago on a project that I've been building in my head for months. I'm calling this design of mine (my first!) the ArcAngel -- a Church Mouse, really. I'm taking the Flats Rat design, a Mouse boat, and curving it up and building the hull with 1/2 x 3/4 strips of No. 2 spruce from the home store.

    By choosing this approach, I have gone outside the design parameters of the Mouse boat -- hard chines, plumb sides, and plywood construction, either stitch-and-glue, preferably, or nail-and-glue. Strip-building is specifically mentioned as not-Mouse, as is lapstrake. Still, I assume that Mouse-makers will realize that anyone such as myself who is not against them is really for them.

    I just finished my second Flats Rat in as many months, and my wife, the Reverend, and I have had one wonderful outing in late summer in our two little paddle boats before being temporarily grounded by a rusted-through muffler in our trusty old truck.

    I'm taking the proven lines and displacement of the Flats Rat and adding a gentle vee-bottom, rounded sides, and tumblehome (for looks and to help with paddle clearance in an otherwise wide hull for a paddle boat (the beam at the sitting place is about 32 inches). I'm keeping the pram ends of the Flats Rat but rounding them to accept the curves and arcs established by the forward and aft bulkheads that I've also rounded up, based on the Flats Rat lines. I'm lofting full size, an idea that David Hazen offers in The Stripper's Guide to Canoe-building.

    I'm going to draw the Flats Rat frames -- bow, stern, forward bulkhead, aft bulkhead -- and then add my curves and vees, first to the bulkheads., which I will cut out of Medium Density Fiberboard (MDF). After putting these two forms on a strongback and springing battens at the sheer, bilge turn, and keel, I'll pick up the shapes of the transoms from the attitude of the battens.

    I'm using No. 2 spruce in 2x6x10- and 12-foot lengths to get the 1/2 x 3/4 (11/16, really, after subtracting the 1/16-inch kerf of the saw blade that I bought from Dave Carnell). One of my design parameters is to use lumber from the home store. I like being able to pick over huge piles of lumber at my own pace, and I dislike the prices and problems of taking whatever they give you at most small lumber yards that cater to home builders. One exception in my city, and not too far from my house, is Niemiecs; they are friendly and helpful. I got a load of radiata pine and yellow pine for the Weekend Skiff there. Still and all, I like the ability to take my time, at my pace, at the home store.

    In Buffalo, New York, I can get spruce in reasonably knot-free runs by concentrating on 2x6s, which I can rip accurately and safely in my basement in lengths of up to 12 feet. This confines me to small boats, or a lot of scarfing. Since I love tiny boats, I don't feel any confinement from this design parameter.

    I've done a summer's worth of reading and research on strip-built boats. This first strip-built project will be a test of several additional design parameters:

  • I'm building with 1/2-inch strips to beef up the hull, because I will coat all surfaces with epoxy but not fiberglass. I'll be interested in the weight difference between my Flats Rats, built of 5 mm lauan underlayment plywood, and this stick-built boat, the ArcAngel.
  • I'll be edge-nailig the strips, and nailing the strips to the frames -- transoms, and bulkheads. The usual strip-built canoe is bent onto temporary frames made of MDF. Fiberglass cloth gives these boats strength and shape-holding ability. My ArcAngel will hold its shape the old-fashioned way, with frames, stringers, and possibly a laminated transversal strip at the mid-point of the hull, halfway between the bulkheads, which are four feet apart, the length of the cockpit.
  • I will use edge-nails, glue, self-tapping deck screws, and some clamping but no staples. I'm building a boat, not putting together a report. I will use toothpicks to fill any holes in the hull made by temporary deck screw clamping. Toothpicks are wood, which is more than I can say for staples. It's bad enough that I depart from tradition in the way I get my wood; adding Office Depot to the mix is one too many for me ... .
  • I'll use Elmer's ProBond glue, which is rated interior/exterior, has a wood-flour thickening effect that the manufacturer calls a gel. Elmer's cleans up with paper towels and water. I will, as I said, cover all surfaces in and out with epoxy. Maybe even two coats.
  • Propulsion will be by double paddle, as with the Flats Rat.
  • Spruce gets the nod over cedar because my home stores don't stock cedar, and I like the looks and feel and characteristics of spruce as much as I like any wood, including pine.
  • Rather than going to the bother of dusting off my router and mounting it in the router table that tried to cut off all my fingers the only time I ever used it, I'm going to use 1/2 by 3/4 strips instead of using cove-and-bead router bits to shape the edges. No thanks to all that fiddly stuff. Epoxy loves gaps, anyway. I won't sweat small gaps as long as the strips are tight on the inside at least.
  • I chose pram ends to maintain the displacement above 200 pounds and because it is generally considered to be a bitch to strip-build a short hull with pointed ends. A boat of about 8 feet in length and 3 feet of beam or less will displace about 225 pounds if the ends are pointed.

    These are the books that I read this summer concerning strip-building of boats:

  • The Stripper's Guide to Canoe-building, by David Hazen. This is a classic. You receive permission to try out your own ideas, with guidance on techniques, or you can use his designs, which others have spoken highly of.
  • Canoecraft, by Ted Moores. I value this book for its clear guidance on techniques. I have chosen among many approaches from many good books on stripping.
  • Featherweight Boatbuilding, by Mac McCarthy. He gives clear instruction on techniques, with plans and guidance for building the Wee Lassie, a beautiful double-paddle boat in 11- or 13-foot lengths.
  • Boatbuilding Manual, 4th edition, by Robert M. Steward; Boatbuilding, by Howard I. Chapelle; and Boatbuilding in Your Own Backyard, by S.S. Rabl. These classic books have valuable sections on traditional strip-building of boats, and the books predate, largely, the advent of epoxy and fiberglass. My techniques borrow heavily from these writers.
  • The Wood and Canvas Canoe, by Jerry Stelmok and Rollin Thurlow. The writers describe a related approach to strip-building.
  • The Strip-Built Sea Kayak, by Nick Schade. This book clearly teaches the modern approach -- staples, 1/4-inch western red cedar strips of bead and cove sandwiched between fiberglass, in and out, and all over.

    ***

    The plans for the Flats Rat are a free download from the website of David Routh, a Texan who sells a number of interesting boat designs; his site also has a narrative and lots of pix of the Flats Rat. The Flats Rat, technically speaking, is a kayak, simply because one uses a double paddle to propel it. Any other resemblances to the usual idea of kayak are largely absent. Still, it's an able craft and will carry a husky or tall or chubby adult and a bunch of gear without strain.

    Flats Rat is the 10th or 20th permutation of a single-sheet plywood boat called Mouse, originally design, then released Open Source-like, to boatbuilders on the Internet. Mouse is the child of an English guy named Gavin Atkin. His website is a treasure trove of free stuff having to do with building boats, computer programs -- free -- for designing boats, and links to a Yahoo club concerning the Mouse:

    The original Mouse is a single sheet of plywood in a vee-bottom hull 8 feet long. The original purpose was to give novices a way to experience stitch-and-glue building techniques without much expense. I like the Flats Rat because I don't have any interest in stitch-and-glue techniques. Flats Rat is meant to be a nail-and-glue boat.

Herkimer

& Perkins

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