View Full Version : solid wood / plywood lapstrake hybrid ?

08-01-2006, 01:20 AM
Anyone ever replace a solid wood strake with a plywood one ? Or how
about one of a different species of wood ?

The boat I'm restoring is built of quartersawn honduras mahogany in 16 ft lengths. Nearly impossible to locate in the PNW. If only one or two strakes needed replacing I could come up with something but I'll be replacing at least 9 of them. So..... I've been trying to think of a suitable substitute.

I was hoping to finish her bright and since most of the damage is on the bottom, I was thinking that maybe with mahogany ply on the bottom it might blend in.

My other option is to use a different type of wood in the long lengths and paint it if it doesn't match.

I'm open to suggestions.

08-01-2006, 08:06 AM
I can't say I've done it, but I have seen somewhere (perhaps Gardner's Dory book) plans drawn up for a plywood garboard with solid planks above.

Depending on the planking stock I can get my hands on, I might have to consider going that route myself.

08-01-2006, 08:40 AM
Yes, Gardner discusses using ply for the garboard strakes, as finding solid wood planks that wide is hard these days.

A lot would depend on the boat design, how it will be used and stored, and how you'd fit the ply in with the existing planks and frames.

08-01-2006, 10:58 AM
Look at the pictures I posted recently of the Pete Culler Wherry Yawl that Lahave Marine Woodworking is currently building - the garboards are ply with solid planking above.

Bob Cleek
08-01-2006, 07:34 PM
Given the markedly different coefficients of expansion, I doubt plywood would be a good companion to natural wood planking, particularly lapstrake, which depends on expansion of the plank faces to keep the laps tight. True, wide stock is hard to come by these days, however, modern adhesives make it possible to reliably scarf stock to suitable size. Lamination is also an option, since it permits layup with the grain running the same direction, unlike plywood with opposing grain.

08-01-2006, 07:35 PM
WB had an article a while back about laminating planks in place...a better proposition.

08-01-2006, 09:48 PM
With the greatest of respect to the two honorable gentlemen posting above me, I reiterate that one of the best small boat builders I know of has been putting a highly-twisted plywood garboard strake on a lapstrake hull with no ill effect. The backbone is Douglas fir, the planking is white pine, and the ply is mahogany, and all planking is traditionally rivetted. When asked by a prospective client, "what sealant do you use in the laps?", Kevin replied, "Good joinery". He has been doing this for at least ten or twelve years with this particular model of boat, one of which has been tender to a yacht that circumnavigated and one that has done at least two trans-Atlantic passages, and have used their dingies hard, and there have been no leaks, pulling of fasteners, etc. That pretty much proved the construction method to me.

08-02-2006, 08:07 PM

That's a beautiful boat. I see how he's used the ply on the garboard strake. Seems like that would work fine. I am curious though, why does he chose to use ply instead of solid wood? Stability, strength?

What's your thought as to using another species of solid wood for replacement strakes? Maybe longleaf pine or wr cedar.

This boat is most likely going to spend most of its' life on a trailer in my yard. It's a small utility (14 ft ) that might take a 20 -25 hp outboard. I don't see it getting any really hard use but at the same time I DO want to use it, not baby it.

08-02-2006, 09:30 PM
"...why does he chose to use ply instead of solid wood? Stability, strength?" - bettyd

The garboard strake twists about 75 degrees in the last two feet to the bow, and finding white pine stock that was close-grained enough to take that amount of torture without splitting when only 3/8" thick was very difficult. Plywood solved the problem.

"What's your thought as to using another species of solid wood for replacement strakes? Maybe longleaf pine or wr cedar." - bettyd

The replacement plank should be of the same density and relative strength as the surrounding planks. In your case, possibly angelique or oroko.