Is Poplar an acceptable choice for boat sides?

[PAR]

SYP is very heavy in comparison to the typical softwoods we use as planking. It has been used, but generally on larger craft, not skiffs.

There are many "Garvey" style hulls available, which incorporate modern methods and provide traditional looks.

[alan white]

When you say scarf, do you mean a dory lap?

[PAR]

I suspect he'd have to do both on solid wood planking Alan. He could also incorporate carvel, battens, laps, wedges or other technique, unless he has access to fairly long, clear lumber.

I'd still be inclined to use plywood planking, even if it was in a traditional build. It's so much more dimensionally stable, comes in pieces plenty wide enough and accepts fasteners readily, not to mention easy to find.

[swanheel]

The more I'm hearing and reading, I am beginning to suspect that you are right about using plywood rather than planks. My initial thoughts were to use scarfing in overlap for the hull. A future question I was going to pose was about the use of modern caulks. The ones that are flexible and have a very good adhesion capability. My idea was to cover this overlap joint (after laying in a good bead of "modern caulk") with expoxy and fiberglass. However in reading many of the threads on this site, I am beginning to rethink that because of the swelling and contraction nature of planks and the non swelling and contraction nature of fiberglass.

[alan white]

This is what I understood. I'm glad you see that you can't construct panels of solid wood without allowing each board to move about its own center. Otherwise, expansion and contraction accumulates over the whole panel, compressing the wood to the point of causing permanent damage, either to the frame, the fasteners/planks, or both.
Now that you know how wood moves, the question is what options are open to you. What was the original construction supposed to be? What caused you to want to change it? Could you show us a drawing from the article with a detail of the planking?

[PAR]

From what I can gather from the one image he's provided, it's a traditional plank over frame job. The seams could be handled in a few different ways, but all will require some "movement" of the planking for moisture gain/lose. This would negate the use of a 'glass sheathing as it would sheer and de-laminate from the planking.

If plywood planking was used, you could glue the seams, then sheathing would be possible. It would also be possible to remove all if not most of the internal frames, replacing them with glued in furniture to provide hull stiffness.

Making these conversions isn't especially hard, but it does require a fair understanding of what's going on with the structure, that most novice builders don't have.

There are "modern" caulks that have a high degree of adhesion, plus good sealant qualities, but it's important you use the right one, particularly when it comes to repairs and maintenance. Some are so sticky, that removal is imposable without damaging the substrate. Others work well, but not underwater unless under pressure inside a seam.

In short, the design should be set up for the method, materials and techniques you'll employ during construction. These older plans use techniques and materials that are either not available or run afoul of newer methods and goos.

Swanheel, if you drop me an email (click on my name) I'll send you some images of what I have available to suit your building style and desires. I have several designs in this general size range. A few flat bottom full plane skiffs, poling skiffs that will accept small outboards, sea sleds that can plane in 6" of water, V bottoms that are more typical of small boats currently on the market, etc. All are easy to build, most from just a handful of plywood sheets, a few 2x4's and a few 1x4's. They're designed for novice construction, perform well and look a lot better then the manufactured stuff you see at the boat ramp.

I have one design that was done for a boat rental outfit. I built a couple of them and a local buddy built a few more, 5 total were placed in service several years ago. They're just over 15', flat bottom, full plane, very stable, fishing skiffs. Powered with 9.9 HP two strokes (some now have Honda 4 strokes) and they easily get up on plane, blast to a fishing hole and can be poled into 5" of water. They were "minimum" builds, no sheathing, just paint and taped seams. They came back after 5 years of continuous use for service. All were repainted, two need some stem repairs where they fought with docks, one had a bashed transom corner and all had wear marks throughout the interior. Most of the repairs were engine related and the boat's needed cosmetic stuff, but that's about it. They're back in service and taking renters out on the lake, so they can run them aground, smash into each other, docks, pilings, etc. I expect I'll see them again in a couple of years, for more ding fixing and repainting.

[swanheel]

PAR, Thanks so much...I'll shoot yu the e-mail for plans. The rental boat sounds like what I'm looking to build. I thought I had posted this earlier, but it looks like it didn't go through. My earliest recollections of a wooden boat was from childhood when I would go with my grandfather. He had a motor, but no boat. We would rent one at the marina---wooden, flat bottom, pointed bow painted dark green with hugh amounts of what looked like roofing tar along every seam. I don't think the bottom was plywood as this was the mid 1950's. But they worked!

[alan white]

Often, too, plywood is specced thinner than the solid wood option. Add glass/epoxy sheathing and it builds faster and a lot of weight is saved, increasing speed, efficiency, and launch/retrieve ease. The bonus is maintainence, which is usually a lot less with ply.
It's better to begin with a plan drawn specifically for plywood rather than converting from solid wood, because more than just planking is involved.
That said, it's probable that enough advice could be found here on the forum to make the changes. It's just a bit of work.
Look at PAR's skiff. He's a designing builder so you've got some good backup compared to calling the--- what was it... Popular Mechanics---- staff and trying to get a hold of the guy who designed the boat fifty years ago.

Originally Posted by alan white

Look at PAR's skiff.

did´nt I say that several posts ago?
The old rule says its as much effort to build a good boat as to build a bad.
So, I would recommend to have a closer look what PAR has to offer.
Regards
Richard

[alan white]

Yes you did say something like that. I checked. Tell you what, we'll split the kickback fee fifty-fifty. $2.50 to you, $2.50 to me. PAR, you're witness.
Just kidding, Swanheel. Don't worry!

Originally Posted by alan white

Yes you did say something like that. I checked. Tell you what, we'll split the kickback fee fifty-fifty. $2.50 to you, $2.50 to me. PAR, you're witness.
Just kidding, Swanheel. Don't worry!

That will not work, or do you really expect he´ll get $10 for HIS design? And I´m shure he will not share the usual sixpack he asks! Bad luck for us Alan, but I take it as a nice gesture!

[PAR]

Sounds like a couple of six packs to me . . .

Swan, I've got your email and I'll get back to you.

[ancient kayaker]

Originally Posted by swanheel

... My idea was to cover this overlap joint (after laying in a good bead of "modern caulk") with expoxy and fiberglass. However in reading many of the threads on this site ...

Also I think fiberglassing a lapstrake will be difficult as the glass will bridge across the laps.

[PAR]

I've never seen a successfully 'glassed traditionally built lapstrake. They just move too much (the planking) and sheer the sheathing, plus the hard corners at the laps issue Terry mentioned.