Batten Seam Construction - drawbacks?

[ken mcclure]

I'm looking at a design for a small power cruiser. I know, I know - the Eun Mara isn't done yet. For various reasons, I think I'm going to do the power boat first.

Anyway, the boat is designed for batten-seam construction - cedar over white oak with oak battens. I've found little in my readings about it, and am a little concerned about the boat's ability to handle life on and off a trailer.

I'd like some enlightenment about how this construction method fares in this kind of situation, and perhaps someone can point me to a written resource.

[ 01-25-2003, 09:00 AM: Message edited by: ken mcclure ]

[Donn]

Can't answer, but it's a great idea for a topic title. smile.gif

[mmd]

I don't have first-hand knowledge to impart, but I know that batten-seam construction was used on the majority of the mahogany lake boats such as Ditchburns and early Chris-Crafts at the beginnings of the last century. These boats dried out all winter in the boathouse as the lakes froze over, and many lasted for decades without the need for major rebuilding. I suspect that the secret would be to use rather narrow planks (4" or so) and to keep the boat in the shade when ashore to prevent rapid drying-out.

[pcford]

What mmd says is correct.
Batten seam speedboats are almost always hauled here in Seattle. Store in a humid place. A barn with dirt floor would be a good example.

I recall seeing a batten seam bright finished sailboat about 25 years ago on Lake Union.

[imported_Steven Bauer]

Which design Ken? Handy Billy? The 20' version of Rambler? Inquiring minds want to know. :D

Steven

Maybe I'll catch up to you with my Eun Mara. The kitchen is really coming along. The soapstone tile came today from Vermont and I picked up the sink and faucet this afternoon for the food prep area on the peninsula. Saturday I drove up to Albion, Maine to get the antique soapstone sink for the clean-up area, a 36 incher. It was a little rough but I took the 6" porter-cable with 80 grit disks to her and cleaned all that lichen right offa her. Took out some chips and scratches too. :D Maybe I'll post some pics when I get a little further along.

[ken mcclure]

I'd LOVE to see pics, Steve!

As to the Eun Mara, molds are made and the inner keel is done and hanging in the rafters. That's it. :(

The boat is a 19' powerboat featured in Ed Monk's book. It's specified to receive 6" cedar planks on the sides and 8" on the bottom, glued and fastened to the battens. The width of the planks is what worries me. I guess I should dig out my wood movement tables and look up cedar. (and sassafras, btw. There's 250bf of it for sale around here somewhere.)

I could use narrower planks, but that increases the number of battens and I'm not sure whether that's a problem or not.

I could switch to plywood for the planking, but that means a lot of sealing on the edges and detracts (in my mind) from the "traditional" construction.

Of course, I could just go ahead and build the darn thing and enjoy it for as long as it lasts. smile.gif

[Peter Malcolm Jardine]

My 36' chris craft is battened. The planks are at least six inches, and above the water line a bit more... The gidley launch I restored was also battened. I can't tell you if it was glued or bedded tho.. but I can tell you it is a great construction for boats that are in and out of the water.

[ken mcclure]

:D That was actually meant to be anti-inflammatory. Dave with one 'm' said he'd love to post answers to questions and give up some of his hard-earned knowledge, but was leery of being flamed.

Because it was his suggestion, I just though it would be kind of nice to associate serious questions with him.

[ken mcclure]

Ahh. Since Dave and Bob are back, I thought I'd drag this back up so they can see it and (hopefully) comment.

[Dave Fleming]

Ken, sorry I have had No experience with batten seam construction.

Aside: I don't mind the way this topic was titled at all but perhaps in the future such questions could leave off the Fleming Soapbox thingy, eh?
My initial postings were more about taking a topic such as this and ***hijacking the thread*** with another topic that easily could have stood on its own. Folla?

[ken mcclure]

Thanks, Dave. Yeah - I folla.

I'm guilty too of the thread creep thing. It's something to which many of us need to pay attention. :rolleyes:

[ken mcclure]

Oh, and lest any latecomers be confused - I changed the subject line of this thread, so Brian and Dave are not as crazy as they seem. smile.gif

[Gary E]

From this article...
http://www.geocities.com/TheTropics/9863/101main.html
The next type of planking is common to mahogany runabouts. It is one of the most difficult methods availible- Batten Seam. Just as the name suggests, the planks are laid edge to edge, and instead of applying caulking between them a batten is attached to the back to waterproof it (see drawing, right).The battens and planking are then screwed on to sawn frames, sometimes with steam bent frames for additional strength.

Here is a 1959 Chris... seems to me that is proof of longevity...
http://www.maplebay.com/7boat.htm

More on early Chris...
http://www.mariner.org/chriscraft/tomcrew.html

More...for this one CRANK UP your speakers..
http://www.speedboatclassics.com/chris_craft_legend.htm

Many more to look at here....
http://search.yahoo.com/bin/search?p=batten-seam+construction+boat

In my opinion, and I have not owned a batten seam boat, but friends have, the batten seam is stronger, leaks less, requires less re-calking, and if I had my druthers, my boat would be built this way.

G

[AngWood]

The author of the website Gary referenced pleads for tolerance since his site is still under construction. Maybe that explains the odd construction sequence:

"...the planks are laid edge to edge, and instead of applying caulking between them a batten is attached to the back to waterproof it (see drawing, right).The battens and planking are then screwed on to sawn frames...."

This leads to a question that I think is relevant here--the same author says batten seam is a very difficult construction method. Is that true?

[Gary E]

AngWood,
Thanks for pointing that mistake out, I have never seen it constructed in that sequence, would be imposible in my opinion. The normal way is to fit a plank, mark the frame where the batten must be, install the batten, then install the plank.

Thanks again,
Gary

[steve sparhawk]

My recollection is that the hull is framed and the battens placed as per plan. Then planks are fitted to join on the center of the battens. That results in the balanced plank layout that will be much in view since most of those runabouts were finished bright.

[ken mcclure]

Gary, thanks for those links! Although I haven't been able to get into the mariner.org site yet.

From everything I can find in my library, batten-seam doesn't seem to be too difficult - just exacting.

The process (grossly simplified here) apparently is to set up the frames, determine the location of the battens, let the battens into the frames and stem and transom framing and then plank so that plank seams are in the center of each batten.

What I also notice is that there are some references to doing it tight-seam (no caulking), caulked with cotton (as in regular carvel) and/or caulked only with a "flexible sealant." Generally the recommendations seem to be tight-seam for bright finish (like a runabout) or caulked with a painted hull.

From what everyone's saying, I shouldn't worry too much about wet/dry cycles with this type of construction. smile.gif Looks like I'm pretty close, then to choosing and starting a boat!