Spiling question

[GRussell]

I read an article recently that described spiling with a batten tacked along each edge of the plank line then fastening a bunch of cross pieces between the battens in a zig zag pattern. I haven't read much about this method in this forum, so I need to ask: What problems could arise? Or is this just a bad idea? I'm building LIZ, glued lap, 4mm ply.
Thanks in advance.
Guy

[Cuyahoga Chuck]

Do you have "Building Ultralight Boats" by Tom Hill? It has a very interesting and more modern way of lining off a mold for glued lap and getting your plank shapes right from the mold stringers.
The method you described is a traditional way of getting plank shapes that has been in use since the time when all lapstrake was done with lumber.
Glued lap can be demanding and costly if you cut planks that aren't usable. Glued lap is not a method that tolerates going from blunder to blunder. You should know your chosen method well before you start.

[Thad]

Good idea. Needs geodesic structure (triangulation, not all parallel cross pieces).

[jalmberg]

I read an article recently that described spiling with a batten tacked along each edge of the plank line then fastening a bunch of cross pieces between the battens in a zig zag pattern. I haven't read much about this method in this forum, so I need to ask: What problems could arise? Or is this just a bad idea? I'm building LIZ, glued lap, 4mm ply.
Thanks in advance.
Guy

I tried something like that, but found that it was a LOT more work than just doing the normal thing: spiling with a compass onto a spiling batten.

The main trick with spiling is not edge-setting the batten. I have a number of 'amusing' posts in my blog where I make just about every possible dumb spiling mistake. It might help you avoid some of them:

http://www.unlikelyboatbuilder.com/2...decided-i.html

[Peerie Maa]

I read an article recently that described spiling with a batten tacked along each edge of the plank line then fastening a bunch of cross pieces between the battens in a zig zag pattern. I haven't read much about this method in this forum, so I need to ask: What problems could arise? Or is this just a bad idea? I'm building LIZ, glued lap, 4mm ply.
Thanks in advance.
Guy

This is a good method if you are using wide streaks, multi-chine rather than trad' clencher plank proportions. As you create a full size pattern, it may be easier to nest the pattern on your ply than when using a spilling batten.

[Jlaup]

Worked fine for me. Wide strakes for sure.
[IMG]
Garboard spiling by jlaupheimer, on Flickr[/IMG]

[jalmberg]

Must take 10 times as long to build all that. What's the advantage?

[Jlaup]

Must take 10 times as long to build all that. What's the advantage?

I do not think it takes more time. The battens are tacked on to the frame and the cross pieces are staples on w/ a pneumatic stapler. 15 minutes work.
The time saving comes getting the planks out. I place the truss upside down on the planking stock. I run a circular saw along the battens that has two small guides 1/8" away from the blade. That gives me a slightly oversized plank. Then I flip the assembly and run a router with a flush bit along the batten. Now I have exact sized planks. Edge setting the battens is not an issue since the cross pieces hold the shape.

[jalmberg]

I do not think it takes more time. The battens are tacked on to the frame and the cross pieces are staples on w/ a pneumatic stapler. 15 minutes work.
The time saving comes getting the planks out. I place the truss upside down on the planking stock. I run a circular saw along the battens that has two small guides 1/8" away from the blade. That gives me a slightly oversized plank. Then I flip the assembly and run a router with a flush bit along the batten. Now I have exact sized planks. Edge setting the battens is not an issue since the cross pieces hold the shape.

Interesting. And the truss lies flat enough on the planking stock? I guess it must have enough flexibility to 'untwist' and lie flat? Because if you have to press it flat, I'd think that would be like edge setting in reverse.

[Jlaup]

The truss untwists just the way a plank would if you took it off the boat. The shape it defines is usually an odd U.

[GRussell]

This is going to work! I used hot glue and tongue depressors. Took about 10 or 15 minutes. I didn't think about making patterns. Sounds like a better way to go than cutting to pencil lines on the real planking ply. So back to the scarfing jig (that's the little dance I do while I'm planing the scarfs). Here's a pic in case anyone is interested.



Thanks again
Guy

[Charles B]

I am building an Oughtred Grey Seal, and have decided to use the compass-and-batten technique to spile the strakes. Just began the process, and it went very quickly on the garboard strake (like 30 minutes to position and mark the batten.) The proof is obviously yet to be seen, when I transfer the measurements onto the plywood, but so far, so good, and certainly faster and easier than making a template. I am blogging the process at greysealbuilder.blogspot.com for anyone who might be interested in following along.