Center 3 boards - close enough to quartersawn?

[Eciton]

 

 

these three boards.  i am looking for wide boards that will have minimal movement widthwise throughout the seasons for a planked boat (lapstrake/clinker style)we want to build.  seems these 3, or even just the 2 on either side of the pith would be the best choice right?  how much do these boards typically move compared to true quartersawn.

i dont have the logs or the saw to get a true 14'' wide quartersawn board from a 28''+ tree so i am hoping to make due with the 15-18'' logs i have 

thoughts?

[appleseedtree]

I'm wrestling with a similar problem and I've put a lot of thought into that. I'm using white pine for my 2nd boat and hoping to get some good 20' long boards. I've got a couple of very nice logs with almost no knots on the outside. I've sawed one of them and here's what I've found. The most clear wood free of knots comes from right under the bark and of course that's flat sawn. You can set the log up on the mill to saw parallel to the bark and get the straightest and clearest wood, but it's not quarter sawn. For me the sapwood is not usable except a little bit at the top of the mast where it'll hopefully never see the water, otherwise the sapwood is prone to rot. If you quarter saw you'll get more stable wood with less shrinkage but you'll also get more knots and defects as they will be near the center, and the sapwood on the outer edge will also be trimmed off. The 3 boards in the center should classify as quarter sawed as the rings will all be close to 90° and even when you set up the log perfectly to get quarter sawn boards you may be setting it up based on the end grain, and who knows which way the grain goes as the blade passes through the log. Usually not as good as you thought it would be over the full length. 

[Den-Den]

Those three are quarter-sawn but will likely have defects near the pith.  I suspect the outside two will warp badly near the pith and the center one may crack there.

[Haleiwa]

Generally you don't want wide boards for lapstrake.  Because there is always some compound curvature, especially near the turn of the bilge, at the stem, and the sternpost or transom, you will have a fairer hull if you stay under five inches or maybe six for a boat longer than say 35 feet or so.  It's common practice to take off a plank out of a thick board and split it on a bandsaw to have matching planks for each side.  The one exception might be the sheer plank.  You can use  a  wider plank there, as the curvature is almost simple, unless you have a lot of tumblehome

[Eciton]

thanks for the replies guys!

the boat we are looking at building is set up for roughly 12'' boards, its a larger version of a Faering.  24'.

i spoke to the designer about using 6'' boards as i think that would be far easier to do but he wants another $300 to redesign.  i may go that route anyway though

[Brad_bb]

You can't get a full width board and have it be Quartersawn.  You have to remove the pith.

It seems like you guys have not read the Reverse Roll Quarter Saw thread? 

With a 28" log you might get a couple 9-10" boards after removing the pith and sapwood.  But most will likely end up 6-8".

[Eciton]

i read it, was a good thread.  i will try that method.

this one was a questions whether the center three boards were close enough to quartersawn to not move too much compared to the outer boards.  

seems like the answer is no. 

[JRWoodchuck]

The pith along with the juvenile growth rings are what cause the most movement in boards. As Brad stated you would have to have big logs to quartersaw 12" boards with no pith/juvenile wood. 

[Sod saw]

Hi Eciton,  I have a question about the design of the hull.

You have described the planking as lap strake, but with wide boards. Haleiwa has talked about normal lap strake planking being some what less wide- perhaps 5 or 6 inches or even less. And sometimes plywood.

Does the overlapping joint (where the strakes actually overlap) fall on the location of the turn of the bilge sometimes known as the chine?  This location may be where the sides and bottom fasten together on a flat bottom boat.  Or it may be where the sides turn in as they rise on a V shaped hull.

With those wide planking boards I would be concerned about them swelling and shrinking with the result of those overlapped seams leaking.  Even quarter sawn.

I have a flat bottom boat where the whole side is one very wide, thin, single plank (old boat). But that floor to side joint is backed up with a board ripped to a varying bevel for the whole length of the joint, the full length of the boat. That boat is only in the upper teens of feet in length.

I don't know who designed your prospective project and I don't wish to offend any one.  Can your navel architect show you working boats that have been sucessfuly built and stood the test of time in the water for a few years?

With the wide planks, can they be made up of narrow planks edge glued?  Will this completed boat be built to WEST system specs? Will each piece of the wood actually be exposed to the water or completely encapsulated?

A lot to think about.

[Eciton]

 

 

similar to this on only longer and wider beam.  the faering and seksring have been around over 1000 years so the design is sound i think.  

I'm unsure about edge gluing planks, i know they get scarfed/riveted to make them longer but edge gluing would require a waterproof glue as the wood is not encased in glass or epoxy.

I am leaning toward marine plywood i think but was tempted to build it more traditionally.

Gislingeboat -The cleaved plank.: Vikingeskibsmuseet i Roskilde

see that link for the real traditional way of building but i dont have the access to oak logs of that size or the endless manpower to split with wedge and axe.

[Haleiwa]

I looked up faering designs, and that's a huge amount of torsion to put on a wide plank.  The picture you show is a modified version of the traditional design, almost like a wherry but double ended instead of a transom.  A few things to keep in mind if you want to use traditional methods.  Scandinavian boatbuiding was done with old growth or close to old growth timbers.  As such it probably had tighter rings than anything available today.  The designs were intended to take advantage of the flexibility of the wood.  Caulk the seams all you want, and make the best rivets you know how, and it will still leak some in use.  The planks will swell, but the hull will also flex in a seaway.  Vikings were tough people; getting wet wasn't a big deal, and they had slaves to bail.  Most Scandinavian boats were in fact built with narrow planks.  The amount of twist , particularly near the stem would have precluded anything else, and probably required steam for the most severe turns.   Keep in mind that boats built in that era would have had a fairly short expected lifespan.  Between storms and getting shot at, not too many raiders lived to a long age, so the boats didn't have to either.  Timber was plentiful and there wasn't much to do over the winter, so they built a new boat as needed.

The temptation to build a traditional design with modern materials always has some potential for trouble.  I love what plywood and epoxy can do, but trying to build a traditional lapstrake with plywood planks has a lot of problems.  First is the exposed edge of the plywood, but a greater problem is the lack of flex in the plywood, especially if you stiffen it with resin and/or cloth.  The Norse builders planked the hull around temporary forms and they bent the ribs to the shape of the hull.  Monoque designs with plywood typically are formed over a frame that will remain in the boat, or pulled into shape by the tension in the sheets (stitch and glue).  The chief difference in application is that the lapstrake design is intended to flex, while the plywood is intended to be rigid.  Consequently, the scantlings required are substantially different; a plywood boat that flexes will crack, while a minimally framed lapstrake that cannot flex will crack.

That's a long way around to say that I don't like wide strakes in a clinker boat.  Looking at your design, if I were to build it with the wide planks, I think I would add a chine log and build it carvel.  Judging from the size of the frames that show, it's clear that the laps are not an integral part of the design's strength.  Maybe make the stems slightly heavier so you can use a deeper rabbet.  There is one really interesting design technique used.  The compound curvature is lessened somewhat by the planks being laid far from parallel to the waterline.  The sheer plank only goes about two thirds the length of the boat, and the main side strake is completely above the waterline at the transom and nearly submerged at the bow.  That makes me wonder if it would be hard to drive, as the forefoot is considerably wider because of it.

Half the fun of building a boat is all the time you spend before construction figuring out what yu want.

[Sod saw]

The photo sort of reminds me of a boat that is popular on the east coast of USA in north atlantic coast. It is called the  Caledonia Yawl.

If you go to a boating site (I have no connection to this site except I watch a lot of their videos) called  offcenterharbor.com

They have boat building videos among hundreds of others.  Even though it is a subscription site, there are no ads allowed. and you can see snipets of videos for free as samples. Very nice bunch of folks and very knowledgable in the boat building restoration field who have been authors and boat writes and technicians and . . . .

I can't speak for any one else but I would rather put my limited time into a project that will last a while and be some what useful for future "kids".  

Good Luck with what ever you decide and I agree that making those decisions can be the most time consuming part of a build.   This is only the beginning of decisions.

enjoy & have fun!

[Eciton]

come on now guys, if people only built boats if it were a good investment there wouldn't be anyone sailing.  ;)

i would very much prefer smaller planks, i think i'll go back to the designer and talk about it again.

there are plenty of solid wooden boats still floating around and lots of painted plywood that do a good job.  there's also a lot of fiberglass with rotted stringers.  

i still wish i knew how to weld aluminum, that would probably be my boat material of choice for low/no maintenance. 

an aluminum viking ship, maybe that's what my sons will inherit.  

[appleseedtree]

Back to the question of the 3 quarter sawn boards:  the answer is maybe, all three boards will be true quarter sawn. You won't know until you saw them. The one that you think might be best might change direction of grain in the middle of the log, and the others turn out better. Another thing to consider is that if you have knots in a quarter sawn board they can be spike knots going across the board, making it useless. I'm
Hoping you'll go with solid wood rather than plywood as that is what I'm a fan of. My 14' sharpie has  2 planks on each side, butted together with splines and 3M 5200, flat sawn as that was the best wood I could get. No problem. The bottom is cross planked with 4-5" wide board and after my wife complained enough about getting her feet wet I covered the bottom and sides just above the waterline with fabric and epoxy. No problems now. The bottom did leak until it would swell up, it lived in a shed most of the time here it pull dry out. The first time out in the spring it would sink at the dock until the boards swelled, hence the covering. 
I'm thinking the best way to saw for the best wood is through and through but parallel to the bark, and cut plenty of extra so you can choose the best boards as you would do at the lumberyard. That's the way I'm sawing for my next one.