oak frames

[rodv]

We are building a 37' Hartley boat, of plywood over wooden frames. We have been advised that we should use green oak for the frames. Does anyone have any thoughts on the use of green oak, or air-dried oak, or kiln-dried as most suitable? Or for that matter on any alternatives.
Be most grateful for any advice.
Roddy

[GordMay]

Don’t recall where I found this, but FWIW:

“Wood Framing” - by Trevor Bolt Yacht Design Ltd.

Use real white bending oak from the South Eastern U.S. The lumber of course is green, kept in the shade, stored wet and salted down. Framing is even tougher work than planking. Better to work when its cool. It is a good idea to relieve the planking of the caulking before reframing so the planking can move when fastened and have good tight contact with the new frames. Prepare the boat by clearing a path for the new sister ribs by removing blocks and nails etc. Cut notches for the new frames through the engine stringers and notch sockets into the keel.

Steambox time: 1/2 hour minimum for small frames, an hour is fine for most. Do not oversteam, it ruins the strength of the wood. Put only enough frames in the steam box that you will be able to put in the boat in an hour period. . Again shores and wood wedges are indispensible. A handy item would be to have a metal cap you could put over the frame head to prevent them splitting as you drive down the frame between the planking and the stringers. The frame corners should be bevelled to prevent splitting in this case. Bevel off the bottom outboard end so it will not dig into the planking as it slides beneath the stringers or around the curve of the bilge, heading under the new notches you cut in the engine stringers until it sets into the new notches cut into the hog or keelson. During its journey towards the keel it must be shored and wedged into the curved shape of the bilge radius or it will simply knock off the planking. The planking may have to be shored up from the outside to prevent this happening.

Once pounded down solid into the sockets and shored and wedged out against the hull planking it is time to nail. One person on the inside with the pinball backing against the frame close by where the nail is coming through. This stops the frame from bouncing and ensures when countersunk that the plank and frame are well cinched tight together. The nailer on the outside can nail in a series so not to confuse the inside assistant. After setting the nails with a nail set, the small amount of boatnail that protrudes through the frame inside may be banged over flush with the frame face. The boatnails are chisel point. The chisel point cutts across the frame grain cutting it, instead of wedging and splitting it. You will notice the nail heads are elongated to provide more grip across the plank grain rings. One frame may take 5-10 minutes, so if you are putting in 8 at one time into the steam box you should be OK. A steambox can be made of plywood with 2x2 in the corners. Sections 8 ft. long can be made to join together. One end must have a hinged door. A metal pipe goes to the boiler. I always have used two steel drums. A 25 gallon 'boiler' suspended inside a 45 gal drum burner. I use a 20 lb. propane tank and tiger torch, it will last for two hours wide open. Wood works fine too but may damage the ground from all the heat. When opening the steambox door expect a blast of steam to go up your sleeve, so wear gloves. After reframing, the boat must be recaulked.

OK, I found the reference - Goto: "Planking & Framing Wood Boats"
http://trawler.ca/planking.htm


You might also want to check out:

Wooden Boat Magazine: http://www.woodenboat.com/

Boat Design Net: http://www.boatdesign.net/

USCG “NVIC 7-95" - Inspection, Repair and Maintenance of Wooden Hulls:
http://www.uscg.mil/hq/g-m/nvic/7_95/n7-95.htm

Wood Handbook, FPL-GTR-113 (WOOD As An Engineering Material, published by the Forest Service Laboratories at the University of Wisconsin)
http://www.fpl.fs.fed.us/documnts/fp.../fplgtr113.htm

HTH,
Gord

[Boracay]

You must be building the Cape Otway 37 design.
The information on the Hartley web site:-
http://www.hartley-boats.com/capeot37.html
does not give much information on the design.
Is it a chine or a round bilge?
If I were building another plywood yacht my main concern would be to make sure that all wood was totally protected by the application of liberal coats of epoxy(WEST system or similar) and that the wood that was reasonably rot proof, took glue well, and had stabilised at a suitable moisture content. The exterior really needs to be protected by a layer of fibreglass matt in epoxy.
I built my Van der Stadt Zeemin in New Guinea and took the advice of the local timber merchant. It turned out very well.
The Hartley that I built (Ferro RORC 32) did develop rot in the cabin top, but that was before WEST system became available.
Green oak frames sounds quite hard to do on a 37' boat. The Hartley designs were all meant for amateur construction and are quite easy to build.
If you contact Hartley & Brookes Associates using one of the addresses given on :-
http://www.hartley-boats.com/contact.html
you should find them to be very helpful.

[By Invitation]

Roddy,

I did this years ago on our Herreshoff. We used green oak and built the steam box from an old cast iron pipe that was once a fire hydrant. The cast pipe worked great, capped the bottom end, had a charcoal fire underneath (boat yard did not take kindly to this fire) and steamed the oak frames till they were flexible. We did add a little anti-freeze ( old timers suggestion) it reduces the amount of blackening of the oak so they look better when installed. Work QUICKLY when you remove the oak frames, you only have a minute or two to work with them. You can always put them back in the steam box if they are not ready. Wear gloves - ther'e really hot frames !

Good Luck,

Scot

[rodv]

Many thanks to all. That's most helpful. It's Hartley's Marksman 37 cabin cruiser we're building, from full size frame plans. We have to order timber boards for the frames, from which the pieces for the frames will be cut out. We thought that if the wood was green there would be a lot of movement as they dried out.
Roddy