Question: 1 or several spiling battens when doing lapstrake.

[Frank Thomas]

Hello all. Just joined the forum and I have a question.

I've started planking my lapstrake wherry. My first boat ever. Garboards are on and I am onto the broadstrakes. My understanding of spiling is that the spiling batten should be narrow enough to fit between the top of the bevel of the previous plank and the mark on the mold indicating the bottom of the plank your getting out. That way you can swing your arc both down from the previous plank and up from the mark from your lining batten.

To accomplish this though, it seems I'll need to create a new spiling batten for every strake as each is a different shape. Is this correct?

A little more detail on my project. My goal is to build the 15' Christmas Wherry designed by Walter Simmons with loftings and plans available from Duck Trap. Being this is my first boat (I do woodworking and furniture building) and wanting to jump right into a lapstrake, I thought it wise to do a 1/3 scale version first.

So I'm building a 5' model while learning techniques from Duck Traps CD boat building building series and Greg Rossel's book "Building Small Boats".

I'm learning alot by doing and hopefully I'll have the skill level required to build a decent example of a 15' Christmas Wherry.

[John Meachen]

The width of the batten needs to be such that it does not obscure any reference marks on the moulds that determine the plank shape.If this means making several battens from a couple of sheets of cheap ply it would still be a very small cost in relation to the rest of the build.The model is a great idea and the time spent will easily be recouped when building the real thing.Good luck with the project.

[Yeadon]

No two planks are ever quite the same, it seems. So you'll end up making a different spiling pattern for each round of planks.

Using thin doorskin material you can hot glue up a few strips that will basically cover the arc of the plank. Make actual templates for the last 18 inches for the hood ends.

[Thorne]

Great choice of boats, one of my favorite designs -- and you'll have a cradle boat to give away when done!

[bob easton]

Great choice for a great looking boat.
Yes, you'll probably need a fresh batten for every plank. That was my experience with a Whitehall. Find cheap doorskin ply and use it like someone else is paying for it.

[Thad]

With lapstrake planking you can use a wide batten, literally a mock plank, because overlapping the lower plank you can scribe the line of the joint directly on the batten. You need to measure the span to the next plank line at each mold to lay out the plank, adding also the lap width. You also need to be careful that the batten is lying at the angle that the plank will lie, and that the lap bevel is right for good landing for the next plank.

[Frank Thomas]

Thanks everyone for the helpful and encouraging responses.

[Ray Frechette Jr]

I have reead one bool on Glued lap that advocated using a jointed spiling batten that could be adjusted as you go along to fit.

Used screws to hold batten in place between taking off and fitting the planks.

[David W Pratt]

What the guy who built Truth advised was to mark the molds, clamp a batten to the edge of the previous plank and to the marks on the molds. These minic the edges of the new plank. Now grab a hot glue gun and a handful of short pieces of scrap and X them along between the battens. When you take it off the boat and lay it down you have a flat panel that will curve to fill the needed space on the boat. Trace onto planking stock, clamp to another layer of stock, cut it out and Ta-Da! two matching planks. A heat gun will help disasemble the battens for the next plank. For practice you could try it with cheap luan just to get the hang of it.
I've seen pictures of people doing something similar for steel boats.
Good luck.

[Eric Hvalsoe]

If you are building a 15 or 16 foot boat I suggest you will be making spiling battens in two or three pieces. I prefer to work from the top, laying the batten just on the beveled lap (leave lap line exposed for spiling) and laying somewhat close to but not covering the lower line off marks. If you glue peices together with just a little bit of hot glue you can break them apart and reshape for the next spiling. At some point you just have to rip another piece of plywood. Hope you understand what 'edge set' means.

[gert]

http://farm1.static.flickr.com/6/6626781_5f1da1cee3.jpg

The battens are the same width as your lands & same thickness as the plank it's mimicking; the bottom one in this image lays exactly where the land is, it's top edge is thus flush with previous plank's top edge and it's bottom edge represents the bottom of the plank ; the top batten is of-coarse the top edge of said plank. These battens can be tweaked for fairness prior to applying the trusses. The top batten (inside edge of plank) doesn't really need to be perfect as this edge will only be seen on the inside of the boat.

[bloggs68]

I just use a wide spiling batten (easier to avoid edge set) and tack it to the molds. You can trace the upper edge of the lower plank directly onto the batten and also the marks for the next plank up at each station.

http://i63.photobucket.com/albums/h131/bloggs1968/gartside10planking228.jpg

At the stem, I put a couple of tick marks ( I use a 6" ruler) to show the stem shape and then take the batten off the boat. Should only take about 5 minutes to spile it off. Lay the spiling batten onto the stock and either nail the marks through onto the stock or if you don't want nail marks in your planks, drill a small hole in the batten at each station to allow a pencil to poke through. Run the batten through the marks and you're done.

Just make sure that you remember to add the width of the lap to the lower mark on the spiling batten or the plank will be too short in width.

One batten does the whole boat.

regards,

AD

[ShagRock]

Bloggs68 - Great photo and nice boat! Just like the old timers did it prior to the invention of doorskins.

[bloggs68]

Bloggs68 - Great photo and nice boat! Just like the old timers did it prior to the invention of doorskins.

Nothig new under the sun in boatbuilding - as you say just like the old timers. This was a nice little Paul Gartside number 127

http://i63.photobucket.com/albums/h131/bloggs1968/Launch2083.jpg

The hardest part about spiling is not the spiling itself- it is making sure that there is no edge set in the batten - just like Eric says.

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[gert]

OK; what is "edge set"?

[Eric Hvalsoe]

Gert,
That is an interesting plank patternmaking technique you've shown us. I've used similiar techniqes, but not for getting out a plank. Great picture, however I think I'll stick with more conventional spiling habits.

Edgeset - if you flip a wide piece of plank stock up on edge between a couple of sawhorses, and try to bend one end up or down in a vertical direction, you are trying to 'edgeset' the board.
It does not work very well - the board does not want to bend that way. When you push a relatively wide thin plank 'up or down' in this way around the shape of a hull, one edge or the other is going to spring away from the molds amidships. The flat sort of spiling board or pieces most of us are talking about should be wrapped around the molds in a natural fashion - that is making contact at all points without you, the boatbuilder, inducing edgeset in the batten. Cause if you've got edgeset in the spiling batten, you will be fighting edgeset in the plank itself. There are times when I induce a fraction of edgeset at the very ends of my spiling battens, but that's another story. And on larger carvel plank vessels, it is not uncommon to edgeset planking, but that planking would be relatively much thicker in proportion and longer lengths would be more willing to be edgeset.

[bloggs68]

And to follow on from what Eric has said, if you have edge set in your spiling batten and then lay out the batten on your stock, it "straightens out" when laid flat and the resultant plank shape is not the one you are trying to put on the boat.

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[Eric Hvalsoe]

exactly

[gert]

Just to clarify; that isn't me or my boat in that image.
Though he is a "pro"
This is, and I'm not:
http://farm3.static.flickr.com/2049/1798326011_1adc3977a7.jpg

One of the advantages of the truss template method is that the real plank can be trimmed directly from the pattern using a pattern bit in your router, because the pattern is right on. "Edge Set" is not an issue, the truss is very stable.
http://farm1.static.flickr.com/178/370139334_aa5179dfea.jpg