View Full Version : What is cold-moulded boatbuilding?

10-12-2004, 07:39 AM
Dear boatbuilders,

I'n new to this forum, so let me introduce myself to you. My name is K.C. Veerman and I live in the Netherlands. I've never built a boat; I've only made furniture and doors/windows for my home.

Now I would like to build a small wooden boat (a medium fast pulling boat such as the Joansa by John Welfsford from New Zealand) and have to decide which technique I will use: clinkers of not, planks or plywood, caulk or epoxy, or "cold-moulded" boatbuilding (what is that?).

Do you know any Internet sources of basic information on boatbuilding techniques that can help me decide?

Best regards,

10-12-2004, 07:48 AM
Numerous sources of information....books available from our host....
But to answer your question......cold molding is a process that enables you to use thin wood veneer and epoxy to fabricate plywood in a very precise pattern, usually the complex shape of a boat hull. You make (generally) a male mold using basic frames and several ribands to establish the shape of the hull, cover with waxed paper or mylar or other material that epoxy would not normally adhere to, then cut narrow pieces of thin wood, secure one end somewhere on the mold form, then carefully follw the basic curve of the hull....usually started at 45 degrees for and aft....then the nexta layer goes on top of the first layer at perhaps 45 degrees fore and aft in the opposite direction or 90 degrees to the first....and so on until you have the required number of layers (usually an even number for balance) to reach the hull design thickness. The thinner the material and the more layers the better the craft will hold her shape...
This isn't the best explanation but perhaps it is a start.

10-12-2004, 09:49 AM
A picture being worth a few words...


The veneer is being applied to the mold.

A finished product.


A web page with more photos.

Cold molded Eel "Glory" (http://members.purelyonline.com/user/robertalbers/photos.htm)

In the Swamp. :D

[ 10-12-2004, 10:57 AM: Message edited by: Venchka ]

Jack Heinlen
10-12-2004, 09:55 AM
Just an addendum to Chuck's description.

The first molded ply boats were built with resourcinal glue, and went into a hot place, over a hundred degrees F, for a period, to cure the glue. They were called 'hot-molded'. With the advent of epoxy glues it became possible to make veneers do your boat-shaped will without the heat, hence 'cold-molded'.

The rest of your question is complex. Say some more about what the boat will be used for. My temptation is always to say, "build the boat out of solid lumber with a minimum of glue." The reason being that the building experience is so much finer; the boat will, if well done, last longer than you will; and there is something special about the skill and desire involved.

A Whitehall, a tradtional livery boat originating in NY, USA, that comes in a variety of flavors from robust to sleek, springs to mind from what you've said. Fine rowing boats, but on the slower end of the spectrum, if a racing shell is at the other. You may want something speedier.

Welcome, by the way.


10-12-2004, 03:40 PM
as opposed to hot molding- way back when all the glues available needed activation via heat and the veneers needed pressure for good bonding. the boats were laid up as above cold and rolled on a trolley into huge autoclaves where under heat and pressure they were turned into monocoque structures

10-12-2004, 05:58 PM
Dutch, Luders in Stamford Connecticut built hot molded boats like that, the L-16 being the best known example. There are some still around.

I recall that cold molding originated with a builder in Scotland in the 19th century. They built large commercial vessels, such as two and three masted cargo schooners. The hull was built up of many layers of planking nailed together, with canvas soaked with turpintine and white lead between each layer.

He later immigrated to New Zealand.

Cuyahoga Chuck
10-12-2004, 09:53 PM
An excellent book on this subject is,"The Laminated Wood Boatbuilder" by Hub Miller. The illustrations alone are worth the price. About
I doubt there is anything as complete on the internet.

10-14-2004, 05:32 AM
Thank you, Jack and everyone else who has answered my question.

I don't think I'd care for much epoxy work and would like to avoid it whenever possible.

I can't find any examples of this Whitehall you mention. Can you point me into the right direction?

Do you or anybody else know of a medium fast pulling boat design (17' long by 3' to 4' wide approximately) that can be built from solid lumber and be caulked?

How do people finish a caulked hull? With varnish?

Best regards to all of you,


Ian McColgin
10-14-2004, 06:01 AM
Varnish is not a caulking compound, and in clinker construction one uses cotton or (larger boat) oakum as a caulking materail under any surface compound.

Take a little bit to survey the amateur building texts available as questions from too great a position of naivate will generate answers that might address your questions but not your needs.

There are many many boat building books. I do not know the Dutch literature but if you can get John Gardiner's "Building Classic Small Craft" you'll get both a variety of good boats to think of bu ilding and lots of information as to how.


10-14-2004, 10:35 AM
This is a Whitehall similar to boats in the John Gardner book listed above. It is clinker built meaning the planks are rivited with copper and the frames (ribs) are steam bent. It rows and sails well. It is about 17' long.



You may have trouble finding the lumber for it in The Netherlands. A similar boat could be built from Bruynzeel marine plywood made in The Netherlands. It is the best made.

Bruynzeel (http://www.bruynzeelmultipanel.com/)

Iain Oughtred, the small boat designer, has designs for pulling boats in his catalog. The boats can be built with traditional clinker methods (solid lumber) or glued plywood clinker construction.

Struan Cottage
Isle of Skye
Scotland IV51 9NS
01470 532 732

In the Swamp. :D