Strip-planked versus Carvel

[Googly]

OK. Is paul Gartside right? He gives a damning summation of Strip Planked hulls on his website (look under FAQ. Well the problem is you see that I have just bought a strip-planked 26 footer to go off and see the world.....eventually. Got her reasonably cheap. She's been built over 7 years and is yet to be launched. Got her surveyed and came out good but hard to survey the cedar under all that GRP Sheathing. I always preferred a Steel 32 footer by Tanton (version of Moitessiers "Tamata"), or Hess's 25 Foot "Renegade"....but oh the bloody money to get either of these babies built by a pro ( I am a neophyte when it comes to boatbuilding). But Gartsides article has me thinking. After all I would be living permanently on this boat once I go off into the big blue and I really don't want me boat cracking up after a few years in the tropics...esp how hard it is to repair this construction.......now I am thinking of selling her and having one of the 2 above boats built. I'd be broke (but I've always been broke) and it'd take me 4 years longer to save the requried amount to get either of the other boats built......ok, so what should I do?

[JimD]

I haven't read the article but seems a bit odd Mr
Gartside would say that, given WB Magazine's latest issue #172 runs an article on Paul's latest boat 'Surprise', which he apparently designed for his own personal use. The construction method mentioned is, yup, strip planking, with a veneer of cold mold over top.

[ishmael]

He makes some good points about strip planking's drawbacks, especially when it's used as a base for glass alone without any diagonal veneers. And on a cruising boat with a deck v what is was originally developed for, open or only partly decked skiffs. And it is difficult to repair, but not impossible. Just a pain in the ass.

On the other hand, it's pretty common. Lot's of small cruisers have been built the way your boat is built. Lot's of completely unsheathed boats have been knocked together over the years without breaking frames or starting fastenings. This probably a factor of a fairly narrow range of moisture content in the wood because of their use, workboats wacked together out of fairly green stock and living most of their lives on the water in cool climates.

I dunno what to tell ya, except that if I were getting ready to set off around the world I'd want complete confidence in my boat.

[ishmael]

Have you got a link to the Tanton boat you like? I just went to the web site and what a hodgepodge. Materials, styles, lengths all mixed together, without an index.

[TR]

Jim & Googly;

"Surprise", (the original) is double planked cedar over bent frames, very traditional, very yachty, nice too! The inner planking layer is 1/4" and the outer 1/2", they are epoxied together and screwed to the frames.

"Surprise II" is designed around strip planking sheathed with double diagonal veneers over. This is to deal with Mr. Gartside's concern that strip planking alone or lightly sheathed will try to tear itself apart. I would agree that this can be the case, but there are many "if's" involved.

How heavy is the planking? How heavy are the frames? Are they Laminated? What are the fastenings? How heavy is the sheathing? Is the hull painted a light or dark colour? How wet or dry is the inside of the boat? Is the backbone laminated or solid timber? Where is the boat kept? Where is she going? And how much attention are you willing to pay to the hull?

These questions need to be answered in detail before condemning your boat. I know of a number of strip-planked boats that have sailed off to the south seas, around the world in fact. Sure there were various problems, there will be in any wooden boat over a number of years. But that's why you have a wooden boat, because she is alive, not cold dead steel.

All the best, Tad.

[JimD]

Originally posted by TR:
Jim & Googly;

"Surprise", (the original) is double planked cedar over bent frames, very traditional, very yachty, nice too! The inner planking layer is 1/4" and the outer 1/2", they are epoxied together and screwed to the frames.

"Surprise II" is designed around strip planking sheathed with double diagonal veneers over. This is to deal with Mr. Gartside's concern that strip planking alone or lightly sheathed will try to tear itself apart. I would agree that this can be the case, but there are many "if's" involved.

How heavy is the planking? How heavy are the frames? Are they Laminated? What are the fastenings? How heavy is the sheathing? Is the hull painted a light or dark colour? How wet or dry is the inside of the boat? Is the backbone laminated or solid timber? Where is the boat kept? Where is she going? And how much attention are you willing to pay to the hull?

These questions need to be answered in detail before condemning your boat. I know of a number of strip-planked boats that have sailed off to the south seas, around the world in fact. Sure there were various problems, there will be in any wooden boat over a number of years. But that's why you have a wooden boat, because she is alive, not cold dead steel.

All the best, Tad.Thanks, Tad. Is Surprise epoxied over top? Why the change in construction for Surprise II? Was it to appeal to the gouge crowd who aren't prepared to plank? Especially puzzling if Surprise is double planked and epoxied which seems to me she's not all that traditional since I'd imagine the planking now can't swell properly so I'd assume Surprise isn't caulked, either. I think Surprise and Surprise II are awesome looking boats. I don't think there are many other designs out there with as much salty good looks as Gartside's. :confused:

[B. Burnside]

Thank you Tad, that was well put.

Surprise I is epoxied over her planking, and not caulked. The two layers of planking are staggered, both running fore and aft. I believe this method can be found in very old boats too, though without epoxy between layers, obviously.

Yes Surprise II's construction was changed to be more accessible to home builders who prefer a glued construction.

Barb

[W Hersey]

AMANTE (50') is strip planked without sheathing, bronze edge-nail fastened and Resorcinol glued. She is very lightly framed, heavily bulkheaded. At 40 years, there seems to be no lose of strength anywhere. She just passed her survey and the cracked frames were not an issue. As on the last survey, they were considered "unnecessary."

She is the first non-carvel vessel I have owned, and this was all new to me. My research indicates that sheathing a well built strip hull is not a good idea unless fully encapsulated (outside and inside) so that it is essentially fiberglass construction with wood used instead of glass roving/mat or whatever they use. The reason is that the hull still will expand and contract with moisture content. Before I owned AMANTE, she had been Awlgripped. After five years there were "paint" cracks all over the place -- not along glue lines. Just all over the place. What a mess. I

[TR]

Jim;

My understanding is that Surprise is not epoxied on the outside, that lead to my comment concerning traditional construction. But from Barb's comments I am now unsure, she mentions "epoxied over her planking"? Perhaps you could clarify for us Barb?

I would be comfortable with the planking layers being bonded together with epoxy, as the planks are fairly small. Traditionally they would be fitted tight, no caulking ("corking" on this coast) except in the full thickness garboard. The garboard was done full thickness because the backbone was big solid timber and would move considerably. The planking was shellaced between layers, or sometimes tarred felt or canvas was used.

Two layers of longitudinal planking bonded together will be stiffer than the single layer alternative. But it will not be as stiff as the diagonal/strip structure. I believe the main reason for going to the strip/diag construction is to eliminate all those frames and fastenings. The boat is just much bigger inside.

Best, Tad.

[JimD]

Tad, wouldn't it seem odd to gouge two layers together and then not encapsulate or at least coat the outside? Without epoxy on the outside the boards would take up water that would then meet up against a near water impermiable layer of expoxy in the middle. What the heck do I know for sure, just a weekend amateur builder, but it does seem off somehow

[B. Burnside]

Tad, Surprise I is sealed with epoxy and painted. "In the traditional manner", says Paul. Don't ask me what that means.

Barb

[JimD]

Originally posted by B. Burnside:
Tad, Surprise I is sealed with epoxy and painted. "In the traditional manner", says Paul. Don't ask me what that means.

BarbSo whazzat mean, Barb? :D . . One thing I noticed right off was the cabin. Looks like he's cold molded the front of it, too. I prefer the straight forward husky work boat look of his designs. Guess he's just done enough of that and wanted to try something more creative. Sure is a nice looking boat, tho.

[TR]

Barbara; Thank you for checking on that.

Jim; I should really stop making assumptions about Surprise before I get in too deep. I can see arguments for leaving the exterior un-epoxied (more traditional) with, perhaps, the possibility of movement tearing things up. But I don't really see that happening, this is a very stiff construction system. Each construction method and it's variants must be looked at as a total system, each decision is part of an overall approach.

And as long as Surprise is living in our temperate rainforest the moisture content in the wood will not change much. A move to the tropics may cause trouble no matter what the construction system.

The other option is sealing the planks to minimize movement (less traditional). This also will create a harder wear surface. The planking is thin (cedar?) and soft. I would want to protect it, but all this epoxy is giving me a headache!

Best, Tad.