View Full Version : plywood vs planking

jim tocchio
10-05-2000, 10:09 PM
i have the plans for woodenboat # 86 a 15' 8" swampscot dory. the plans call for the boat to be built with plywood. i have spoken to a few people who have built simular dorys and they have used planking. i would like to build wb #86 with planking (white cedar) for a heaver boat (i will be using this boat in the ocean). can i use the plans i have? do i have to make major adjustments?

10-06-2000, 06:49 AM
Well, at minimum the entire interior structure would have to change. Someone will need to engineer that. Either empirically or by exotic mystical mathematical calculation.
This brings to mind an ineresting question(s): Why do we always try to change plans? God knows NA/Designers, by and large, are not becomming fat-cats with their work. Why not PAY one to design the boat you really want? Their creditors, at least, will thank you.

[This message has been edited by TomRobb (edited 10-06-2000).]

Ian McColgin
10-06-2000, 08:46 AM
Check Gardner's "The Dory Book" for the scantlings you'll need. Personally, I'd go with the ply but what you want to do is perfectly doable.

Keith Wilson
10-06-2000, 09:10 AM
Swampscott dories were, of course, originally built with "natural" wood planking, usually pine, so converting back shouldn't be difficult, and will result in a perfectly good boat. Copy the scantlings from a similar design, and you'll be all right. If you're not worried about weight, make it just a little more stout. John Gardner had plans for several dories of this type in Building Classic Small Craft Vols. 1 & 2, but "The Dory Book" is really complete and will tell you all you need to know. You might even find plans for a dory you like better. The WoodenBoat store sells it for $26, among others.

People change plans to adapt them to their particular use and preferences, and because it's fun, the same reason we build boats. And why not, as long as it's not too stupid? It's our time and money, and we have to live with the results.

Mike Hofgren
10-09-2000, 07:22 PM
I don't think I'd do that.

I had the good fortune (of Father God not being harmed) when the eye of hurricane Carol passed over Hampton Bays L.I. in 1954. That was just after plywood had become a popular boatbuilding material.

I remember - Tianna is a small bay, we knew the names and who were the owners of most craft - I remember some boats that 'got caught' were severely damaged. The ones in planking splintered and broke up . . pretty badly, basket cases, . . the plywood ones suffered badly from serious impact, but they would have holes punched in them . . there was something left, the structure wasn't damaged . . maybe a hole to be glassed in, or otherwise patched.

Applied correctly . . in general, plywood is stroonnger. I'd observe the result of cold molding, layering grain in obtuse directions, gives same result as plywood . . is the strongest way we know.

Wooden Boat effectively explains traditional materials application, many of which provide superb and long lived result.

Rather than mechanically fastening plywood and looking to that as the strength, - I like to bond the plywood panels one-to-the-other with fiberglass: the craft is very strong and is very light; - planning to properly glass encase the vessel, will give very good life.

I don't underestimate the great skill of creating a very strong structure that best building of plank-on-frame causes.

If someone designed a boat to be made in plywood, I'd go with that.

There are many ways to display attractive natural woods in plywood boat. A well built plywood boat is VERY strong. I first saw than at Hampton Bays in 1954. http://media4.hypernet.com/~dick/ubb/biggrin.gif

Bear's Oil
10-09-2000, 09:00 PM
Contemplating building a scow/garvey (see various Larry/scow threads), I've come to wonder about cross planking bottoms using tongue and groove material, sealed and end-glued with epoxy. Any comment? Terribly long sentence, I know....