In article , jotis
writes
Hello -

I would like to build a dinghy or small sailboat using the cold-molded
plywood method, sometimes called laminated veneer.

I built a cold-moulded 11 foot International moth class dinghy about 30
years ago.

I have looked a couple of books (Ruel Parker's and Hub Miller), but their
emphasis seems to be on large yachts. Since I want to make a small boat,
neither book answers the questions about ;

1. Selection of veneer, ie, wood type, appropriate thickness, number of plys
(plies?), etc

In above case, 3-ply - 1mm sapele veneer outer, 2.5 mm gaboon core, 1mm
sapele inner.
.

2. Mold method set-ups which are more suited to small boats.

3. The best method for making and setting up stems and transoms.

Built upside down, male mould. Stem, keel/centreboard case, and transom
formed part of the mould. Remainder was 1.5" x 3/4" softwood battens
(roofing battens), over formers 18" apart. Fair it all up with a plane.
Put clingfilm over the softwood battens to prevent adhesion.

Staple veneers to keel/mould at 45 degrees to centreline. (other
configurations are possible). Spile edges of veneers so they fit tightly
to each other. Repeat with next veneer layer at 45 degrees the other
way, this time with glue (wetting out both veneer surfaces with a
flexible trowel). Allow to cure. Remove staples and do outer layer.
Remove more staples, glue on external gunwale, and then prise hull from
mould, being thankful that you were thorough at the clingfilm stage.

I used 47,000 staples for an 11 foot boat. I know because I used nine
and a half packets of 5,000 staples. Removing them takes a while, even
after using little veneer pads to staple through. And then you have to
fill all the little holes with mahogany filler, varnishing doesn't fill
them.

You could use less staples (just for positioning the planks) and use
vacuum bagging instead.

4. Adhesives - must if be epoxy? How about using the "construction" types
glues?

Resorcinal (eg Aerodux® etc) or epoxy.

5. General "comfort talk" to aspiring cold-molders.

Its old, labour-intensive technology. Especially if you are only
building one hull.

Can anybody help? Your specific suggegestions or references will be greatly
appreciated.

Don't do it ...

Cedar strip with epoxy/glass skins is less work, and IMO can produce an
aesthetically and structurally equivalent (or even superior) end result
if well done, compared with cold moulding.


--
Mark Dunlop