Spiling question

[Gordon Hafner]

I'm getting ready to start spiling my Washington County peapod. I was planning going the traditional approach with a spiling batten and compass (a la Greg Rossel). My sources recommend 1/8" plywood for the batten; neither of my local big box stores ( Home Depot or Lowe's) have plywood that thin. The closest is 1/4" which is likely too thick. Would MDF or some similar product that's 1/8" thick work? I'd be a bit worried it would kink rather than bend with the curves of the hull.

On the same topic, a friend who's built a number of small boats recommended another approach, using two thin battens run along the upper and lower edges of the lined off plank, but securing them with a bunch of short pieces of wood hot glued in place. The result is a bit like a drunken ladder, but the cross pieces preserve the relative distance between the upper and lower battens. You then take it off the hull, lay it on the stock, and trace the edges. He says he's had good results but I haven't run across it.

Thoughts?

Thanks,

Gordon

[willin woodworks]

Stick with compass. Tried and true and basically fool proof.

you can make a spiling batten by ripping and planing a long straight piece of stock. Pine, poplar, whatever they have at the HD or Loewes. You can use it over and over by erasing your pencil marks and gently sanding.

[UCanoe_2]

Hi Gordon, old McLean HS graduate here. I'm not an expert, and others with more knowledge will chime in soon.

I cannibalized a hollow core door from the ReStore for pattern material. Of course, this method results in door sized pieces which you would have to splice together somehow. You should have plenty of lumber sources in your area other than the big box stores and may want to expand your search.

resized hollow core.jpg

I used the "drunken ladder" method to lay out my sheer strakes. I found that the hot glue did not survive much handling, and recommend fastening the cross members with small screws. Use plenty of diagonals to ensure that the pattern holds its shape.

In addition to its use as a pattern for layout, the ladder can also be used as a template for cutting plank to exact size using a laminate trimmer bit on a router. The pattern in the second photo is on the underside of the plank (ignore finger over lens).

resized pattern check stbd.jpg

resized got smarter except.jpg

[pvg]

1/8" ply is often called "door skin", maybe ask for that. Also, I found cheap 1/4" ply to be better than 1/8" which can be too "floppy"...

[timo4352]

Surely underlayment from home cheapo is good for spiling, and making patterns.
It was inexpensive last time I bought it and it is thinner than the quarter inch they may advertise it as....like 5mm, or 3/16"

[ron ll]

I’ve always used cheap luan door skin. Unfortunately it’s not as cheap as it used to be.

[TerryLL]

It's important to use spiling battens that are similar in flexibility to the plank stock, especially if the moulds are widely spaced. If the spiling stock is super flexible it can flatten and sag between the moulds.

[wizbang 13]

Prick dem wit composs an battong rip from plankin board

[Kunzwerks]

Your friend has the right idea. I nailed the battens in place and used staples to secure the cross pieces to the battens. Of course, don’t sink the nail heads in all the way, so they can be removed and choose staple length that doesn’t go through the batten. Once one strake is finished the “ladder” can be disassembled and battens secured to the next strake.

5C85C244-41EC-4384-B018-CF8F72920960.jpg

[ptscho]

Underlayment from the big box store works well. More than 1/8 but less than 1/4. All that really matters if you have something that you don't edge set.

Personally, I found the hot glue ladder truss method would spring even with a ton of triangles in it. A batten and compass is hard to visualize whether the plank can be gotten out of a given piece of stock (unless you have real wide stock). I would recommend a batten and tabs glued to meet the edge of the planking - effectively the same as spiling with a compass but you can see the total size when you lay it out.

[adamarthurryan]

+1 on just ripping a batten out of wood. Select very clear, very straight grain. Plane it smooth. I used 1/4" and it was plenty flexible. Probably too flexible... It was definitely too narrow at 2 inches or so. I had problems with edge set at the bow.

[DeanP]

Here's my drunken ladder. It was a lot of work, but worked well to get an accurate shape for the stem. I used epoxy and lots of spring clamps to hold it all in place. The shape held true and allowed me to make a good fitting stem.

For the most part however, I used the compass method to spile the many plies on this cold molded hull. It was reasonably quick one I got the hang of it.

IMG_0230.jpg

Good luck,

[wizbang 13]

Oh geeze, a jogglestick would have logged that shape right quick.

[DeanP]

Oh geeze, a jogglestick would have logged that shape right quick.

Now I have to ask, what's a jogglestick?

[Mike J]

I greatly prefer the ladder method over traditional spiling, mainly because a decently built ladder requires no additional fairing to transfer to the planking stock. For me, I got the fastest and most accurate ladders by using rectangles of 1/8" masonite from 1 to 4 inches wide, hot gluing the largest pieces where there was less curve. Once the planking was cut, a few taps with a hammer would knock the pieces loose to re-use for the next pattern. The hot glue also was much more rigid than staples or nails, and I could easily move the 18' ladders by myself just lifting from the middle.
16363798835_e39098b312_z.jpg
I agree that your battens should be the same thickness as your planking stock, and if you are builing lapstrake they should be the same width as your gains.
Lastly, the ladders make it possible to preview the planks for fairness right on the molds and make adjustment by popping loose a piece or two and regluing.

Good luck with your build,
Mike

[Don Z.]

Now I have to ask, what's a jogglestick?

Key
4223
Author
Roger C.E. Simpson
Title
Other Ways: The Incredible Jogglestick
Magazine
WoodenBoat
Month
Mar/Apr
Year
1981
Issue
39
Start Page
106
Purchase
Purchase Issue 39 Securely through WoodenBoat Store
Subjects
Bulkhead--scribing method (jogglestick),
Patternmaking--from lofting, jogglestick method/technique of Roger Simpson,
Simpson, Roger C.E., author and photographer--"Other Ways: The Incredible Jogglestick,"
Scribing--jogglestick method/Roger Simpson,

[keith66]

My dad used to use the drunken ladder system for planking patterns though he didnt call it that. He learnt it at Jack Holts boatbuilders Putney in the early 50's so the idea has been around a long time. Told me they were building the first Merlin Rockets & similar.