View Full Version : Plank Fastening Questions - Poulsbo Boat
06-09-2003, 01:13 PM
Inspired by Walcheren's beautiful rendition of a 16' Poulsbo Boat, I ordered the CWB Monograph on the topic, c/w lines and offsets. There is also a "HTB a Poulsbo Boat" section. Although I'm still in the planning stages, the information in the CWB publication is basic at best, and questions have begun to bubble to the surface...
Frames are ½" x 1" oak. Carvel planks are 9/16" cedar. Ronald Young (designer and builder) used clenched nails (copper or galvanized depending upon "when") to fasten. I tried the "search" but did not happen upon what length of clench nails to use. In this case total of 1 1/16" frame and plank thickness. i.e. So, how much nail should be protrude to get a good clinch - use 1 ½" nails?
And to those who don't appreciate the aesthetics of clench nailing, (maybe even me) what other type of fastening sytem would be appropriate?
Bronze Ring Nails - 1" x what gauge?
Bronze screws - 1" x what gauge?
Copper rivets and burrs? gauge?
(Approx. 2500 plank fasteners req'd)
Thanks in advance.
06-12-2003, 09:49 AM
Ask these folks:
06-13-2003, 12:48 PM
Dirk / Walcheren:
Are you out there? With what / how did you fasten your planks? Are you happy with the way thay turned out?
06-13-2003, 10:32 PM
Hi again. I did the Catspaw with rivets (1 1/4" x 1/8" )and burrs. Plugged the holes. I can't imagine I did all that when I look at it now but it looks great and is solid. Planks 9/16 same is the Poulsbo. If you plan an 18 footer you might want to go to a 5/8 plank. Remember she is the Queen of the Tumblehome so quite a bit of wood comes off fairing the hull and fitting the planks to the curvature of the frames. I did not want to do the rivets again and thought screws would be easier, faster. However. For screws you have to drill a hole with countersink, put red lead paint or whatever in the whole, put the screw in dipped in whatever and later plug the hole with wood or putty. I used red lead putty. Thought it would be quicker but no. Fairing i.e. getting rid of the holes was very difficult. Also, once the putty is in you better put some red lead paint over it otherwise the stuff dries out quite quickly. Turned out to be a lot of work also. Clench nails I do not know anything about. Size of screws? I used #8 SS, 1". I was not going to spend the money getting bronze etc. And as it turns out, I will not have my boat parked in the marina because of expense so she will be sitting on a trailer high and dry so stainless steel above and below the waterline will last a long time. I don't know much more. Dirk.
06-13-2003, 10:49 PM
Here is a picture of screws. http://www.imagestation.com/picture/sraid65/p4d413de1914b4db164ea2c4a2589cadf/fbee9b06.jpg
06-14-2003, 06:35 AM
I suspected the clenched nails worked when they were banging out 4 boats per month and it was "quick and dirty". Screws or rivets make more sense to me. So, more work at the drawing board to come and we'll see where it ends up.
In the HTB section they talk about steaming evrey plank. Did you have to do that? I imagine there still is a fair bit of backing out to do, and , as you say, fairing afterwards.
06-14-2003, 12:41 PM
Good morning. Yes I steamed all planks, mounted them temporarily with clamps, took them off the next day and installed them permanently. I used 1x8 first growth cedar, beautiful stuff and ended up getting away with spliting them in half and each of these planks 9 cm plus could be shaped to fit. As you may see on the photo, the shear plank is also 2 - 9 cm. planks but I made the joint invisible so now the shear looks like one wide plank. Looks better. You do have to cut the transum ends in half again for about 4 or 5 feet to shape the tumblehome. Once done I realised that I have one less plank per side compared with the diagrams in the book so you could make the planks slightly narrower and use one more. I could not get the shear on in the beginning, too many curves. So I started with the gar board and the rub strake. Anyway, I could go on but won't.Let the questions come. Dirk. http://www.imagestation.com/picture/sraid65/p6195fdd6101298b10c9f52624e4df784/fbedbda7.jpg
On the bottom picture you can see how far I did cut into the planks lenghthwise in order to get the curve of the transom.
06-15-2003, 06:10 AM
Great pictures - it's nice to have them as a log of your work. More questions brewing....
In the drawings from CWB, they show the frames landing directly on the keel, and the garboard flush to the top of the keel. It seems there would be no limber holes with that approach. Did you install a keel batten or perhaps rabbet the garboard lower in order to create limber holes (like how I believe a Catspaw is constructed)? Withe either method, one needs little lands, or wedges to transition the frames back to the lines of the hull?
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