Cold Mold

[Skools Out]

what thickness wood do you skin the hull with on cold mold hulls?

[alan white]

It is based on the ease in which the wood can bend at the most rounded part of the hull, and other factors such as direction of the layer and structural purpose of the layer involved. No two designs are necessarily alike. Quite thick or very thin.
I'm no expert though. Some here have probably designed and built cold molded hulls, and they can help you further.

Alan

[Raggi_Thor]

For most boats I would recommend only three plies in the plywood, then it's easier to bend. That means normally 3 to 4mm thickness.
See for example http://www.dixdesign.com/radply.htm.
In Didi 26 the round bilge is made of two layers of 4.5mm plywood, or 4mm if you can't find 4.5. Just an example.

[gonzo]

Large double planked hulls can have 2" layers. They are all different depending on size and use.

[alan white]

I am looking at different methods of planking a St Pierre dory. My first thought is to go with two layers, both vert. grain fir. Might be vertical 5/8" inside and 3/8" fore and aft outside, spiled for aesthetics. Never done it before, so any thoughts...?

A.

[Raggi_Thor]

Isn't that a hard chine hull?
If so, you will save time using plywood.

[Raggi_Thor]

Originally Posted by alan white

I... fore and aft outside, spiled for aesthetics. ....

I missed that part, fore and aft planks may look better :-)

[alan white]

The first layer probably ought to be plywood, I guess. A lot easier. The spiled layer, maybe solid wood (dories wouldn't have much edge-set to the planks).

A.

[Skools Out]

thanks for this info so far.

[alan white]

Start with the boat, S.O., and you'll get some good advice from someone here who knows cold molding. What boat design is involved?

A.