Strip planking / Cold molded ?

[Raggi_Thor]

fcfc,
If you want to read in french, look at:
http://www.icarai.net/
They have plans from Dudley Dix and others.

[nero]

Par had a correct reply.

This is half of one hull of my catamaran. I started putting the strips on the forms yesterday. The forms are female.

The boat is 18 mm cypress (quarter sawn) strips with the widest at 50 mm. The wood provides the structure fore and aft. Across the grain the uni and bi axel 10oz fiberglass cloth and epoxy hold it together. ... I hope.

I am trying a 'lock miter joint' to join my strips lengthwise. Some are epoxied together before I lay them on the boat. Others are joined on the boat. It seems to be working quite well. The joing lines up easier than a scarf joint. It also will be a bit better than a but joint.

I cut several ends at one time with the lock miter router bit and a Hitachi router. I need to make up a jig to make that process even faster.

Here are some of the build photos.

You can do a lot with strip planking as far as rounded shapes.

[jfblouin]

Very beautyful hull.

I use the joint named finger joint. For a 19 mm (3/4 ") plank, I have 62 mm (2 1/2 ") long of 1:20 (3 degres) surface plus 16.2 mm (5/8 ") of end-grain surface.

A 1:8 scarf for 19 mm (3/4 ") plank have 150 mm (6 ") of 7 degres surface.

My joint with epoxy is stronger than plain wood with small knots but less stronger than clear plain wood. I dont make compare with scarf.

[PAR]

In most applications, fancy joints on the strips aren't necessary, a butt joint will do and is the fast way through. Staggering the butts, like any joint should be, is the ticket. Most strip hulls get sheathed with something, veneers, glass, etc. so the need it's as big as it may seem. The strip just above and below the joined section of planking will lend a great deal of strength to the joint, if glued and fastened properly.

[yokebutt]

I kind of like the finger-joint, especially if you can do away with that step near the surface of the wood, since it effectively puts a butt-joint at the most highly stressed fibers. (in bending) We might as well start looking into it, because the long lengths of good lumber will not get any easier to find in the future. (nor any cheaper)

Yokebutt-joint. (No, contrary to popular belief, (although I can see why you suspect it) I don't smoke it)

[chandler]

The only problem with finger joints is they will create hard spots as opposed to a scarf. they will also break in any type of hard bend .

[Raggi_Thor]

When scarfing plywood, the scarf become stiffer than the plywwod around so you get a flat area. This is sometimes more work to fill and sand than two very small hard spots from a simple step joint.

[cyclops]

I have 1 option. NO long marine ply, over 10' ? Put down 3 staggered layers of 1/4" ply. It does work very well, as we Dinosours continue to do our best in a decreasing supply world of marine woods.