Building a Stitch-and-Glue Flat-Bottomed Skiff from Plywood

Building a Scratch-built Plywood Stitch-and-Glue Flat-bottom Skiff

This web site will document my attempt to build and own a plywood stitch-and-glue skiff that I intend to use on lakes and rivers in and around Anchorage, Alaska.

Goals:

Basically, I want a boat...:

that is small enough to fit in my garage,
that is big enough to take fishing in Resurrection and Kachemak Bays,
that has a shallow enough draft to take up and down Little Willow Creek, the Deshka and both the Big and Little Susitna Rivers,
that has a deep-vee hull for stability, speed and a (reasonably) dry ride on the open ocean,
that can be powered by paddle, sail or outboard, and
that is quick to build, since fishing season is coming, and
that is inexpensive to build and operate.

Yeah, I know...that won't happen any time soon. However, from this wishlist, I can develop a reasonable set of requirements. I figure that I will mostly be using the boat to goof of on Cheney Lake (where I live) and to go fishing on the various rivers near Anchorage. If I want to go fishing on rivers like the Big and Little Susitna Rivers, the Deshka or Willow Creek and Little Willow Creek, then I need the ability to use an outboard -- I don't see myself sailing or rowing up those rivers and creeks :) Ideally, it would be great to be able to sail on the Anchorage area lakes, but realistically, building a boat that is capable of sailing well and that is capable of rowing or motoring around with a small outboard in shallow water is unlikely, so I will drop the sailing requirement. I've always thought it would be cool to build a catamaran along the lines of a little Hobie Cat anyway, so maybe that will be a future project :)

I would like to be able to putz around on the protected bays near Anchorage, like Prince William Sound and Resurrection Bay, but again, it is unrealistic to expect to be able to handle the waves and current on the ocean in a boat that is small enough to keep in my garage and that can be built on my budget. After consulting with a coworker who is a much more experienced boater than I am, I think I would need a boat that is close to twice the size I am considering if I wanted to go in the ocean. While Resurrection and Kachemak Bays can be pretty calm, they can also get pretty rough when the weather turns. And Prince William Sound is open water once you get past Blackstone Bay. I don't think a twelve to sixteen foot boat with two feet of freeboard will cut it on the ocean.

Finally, I want something I can build fairly quickly and fairly, well, cheaply. Breakup is about two months away and fishing season is only about a month after that, so the boat I build needs to be very simple so I can put it together quickly. While my wishlist is pretty extravagant, I think I have narrowed the design down to something more reasonable.

The Design:

With a more realistic list of requirements, I have decided to build a flatt-bottom skiff from plywood using the stitch-and-glue method. A flat bottom skiff is about as basic a design as you can get. There are only four major components to a flat-bottom skiff -- the floor, two gunnels and the transom. The stitch-and-glue construction method is also about the simplest boat-building method in existence -- you cut the pieces to shape, wire them together with a little narrow-gauge copper wire, epoxy the pieces together and cover with another coat of fiberglass. Stitch-and-glue is strong as well, and is very forgiving of builder mistakes. The epoxy joints are stronger than the wood from which the boat is built, as evidenced by a number of builder testimonials where pieces of plywood joined together with stitch-and-glue butt joints have delaminated rather than break the epoxy joints. If I have material left over, I'll conduct similar tests and post the results here.

Materials:

No doubt, using marine grade plywood for the hull is by far the best option. The wood used to make marine grade plywood must meet a stricter set of requirements than exterior grade plywood. Interior grade plywood is not an option -- there are often too many voids in interior grade, and the glue is not at all waterproof -- a bad thing for a boat. If there are hidden voids in the internal laminations, then interior grade plywood could break when trying to bend it over the frames in the boat hull, wasting a lot of material. Using interior grade plywood therefore is just a false economy. However, after reading what other kit boat manufacturers have said about exterior grade plywood and after comparing costs between exterior and marine grade plywoods, I have decided to go with exterior grade plywood on my boat. This boat is an experiment -- I am not sure that I will be able to finish it and even if I do, I am not sure that it will float -- so I don't really want to spend the money on premium materials for what very well might be a waste of time. Besides, I intend to wrap the whole thing in epoxy and fiberglass, which is where I expect most of the strength and water resistance to come from.

Therefore, I have decided to use 3/4" exterior grade plywood (not sure what species; it was left over from a previous project) for the transom and frames, 5.2mm (just under 1/4") lauan mahogany exterior grade plywood for the sides of the hull ($14.40 for a 4x8 sheet at Lowes!!!) and 1/2" exterior grade douglas fir plywood for the bottom of the hull. I have some fir 2x2s in the garage that I will use to make stringers, rub rails and other shaped parts. I plan on using West System epoxy to glue the parts together and to impregnate the fiberglass cloth. West System has been around forever, and lots of amateur and professional boat builders alike have used it with excellent results. In fact, if I recall correctly, West System was designed for boat building and later adopted by the amateur-built experimental aircraft guys (yes, I am one of them, too).