what is the most popular domestic hardwood (US) for cold molding

I was wondering what that was all about
no worries
cedar does not do well in cold molded applications because of its habit of puckering if the epoxy impregnation is broken

ends up looking like reverse hail damage

I suspect cedar is the same

Tad wrote in another thread that he did a large build using cedar sandwiched between Dougy

Im starting to thing a sandwich approach myself

 

http://www.classicyachtforsale.com/syWhiteHawk.html

Built 1978.......current asking price roughly 3-4 times what she cost to build. Her hull is "Thick Skin" cold-molded laminated of 5 layers with no framing except bulkheads, floors, backbone, clamp and deck beams.

Hull skin is 5 layers, the inside, 5/8" white cedar first layer is run fore and aft over the bulkheads, with temporary molds between, set up on the backbone right side up. (building right side up was a mistake, but she was the first really big cold-molded yacht built in the US) Second, third, and fourth layers are diagonal, 5/16", 5/8", and 5/16", also white cedar. The fifth layer is fore and aft 5/8" mahogany. Total thickness is 2 1/2", inner layers fastened together with West System epoxy and bronze anchorfast nails, outer layer with bronze screws countersunk and plugged. She was not sheathed with fiberglass as is now the practice, though the outside planking was given many coats of epoxy.

In the late 1990's she had an engine room fire which burned off some of the deck but didn't really affect the hull at all. As a result they did some new holes for through hulls, the skin was dry as a bone and perfect inside.

After Whitehawk (92' ketch, 1978), came WhiteFin (90' sloop 1985), Signe (100' ketch 1988), Sophie (90' sloop 1991), Hetarios (124' ketch 1992), Chanty (51' ketch 1994), Liberty (80' high-speed motoryacht 1995), Antonisa (124' sloop 1999), Scheherazade (154' ketch 2002) plus some other smaller boats. All were built mainly of softwood, similar to WhiteHawk, except every one after her was started upside down. These were all designed by the firm I worked for, were built all over the world, and all are currently sailing and have had no structural issues involving their cold-molded softwood structures. We stopped using mahogany and stuck with Douglas Fir, and white or red cedar. For these big boats with huge loads imposed by their modern rigs we often added carbon in high load areas.

 

now those are some details I can sink my teeth into Tad
thanks
B

I found some nice inexpensive cedar a while back and have been taking a new look at it for my own project

 

Other info on longevity of epoxy bonded boats....from the Gougeon Brothers magazine....see the article "Wood/Epoxy Longevity"

http://www.epoxyworks.com/17/index17.html

 

wasn't whitefin bruce king

 

Whitehawk, WhiteFin, and all the boats mentioned above were designed by Bruce King Yacht Design where I was employed from 1987-2001, and chief designer from 1990 on.....

 

hey Tad your rep and your posts are exactly equal

 

very impressive Tad, did b king design whitehawk & whitefin, or were they by another designer at the firm

 

Peter,

Bruce was certainly the principal designer, but as you know these big projects are all collaborative. George Thomas did much of the engineering before moving on to work for the Gougeon's, Paul Kotzebue http://www.pkboatplans.com/index.html was there before me, and WhiteFin's interior was done by Joe Artese.

The first two, WhiteHawk and WhiteFin, were built from very few drawings, probably less than 25 total. Actually most of the drawings were of spars, rigging, and deck hardware because at the time none of it was available off the shelf. They had to design and build turnbuckles for Whitehawk. And there were no systems drawings.

I started with Signe and did every drawing for her, something over 80 big sheets all in pencil at 1/2" scale. She was a much more complex build due to the centerboard, two generators, skylight mizzenmast partners...etc.

 

wow, is this the signe clapton wrote a song on charter about

http://www.youtube.com/watch?v=owOGDEJr3ts

 

Peter,

I have no idea...but it's possible....her first owner was American and I think then she went to a Brit and was/is offered for charter for many years.....here she is....$50-55k per week....http://www.ypigroup.com/yacht-signe-charter.html