knees

**Crip** · 03-21-2002, 08:06 PM

Hello all,
I'm sure there are as many methods as builders, but can someone explain the easiest way to mark the curve of the hull and the deck on to a piece of stock that will become a knee?
Looking forward to seeing how many posts this topic recieves

Crip
my boat page

**Dave Fleming** · 03-21-2002, 08:21 PM

Ya make a template or pattern of the shape and then bandsoar it out proud of the cut line and then plane and chisel to fair, ya folla?

**SailBoatDude** · 03-21-2002, 10:44 PM

Take a piece of door skin material, cut it to a close fit by eye and clamp into position where the knee is to be. It don't need be pretty as it's just a template. Using a dividers or compass and being careful to maintain a constant direction (don't roll the dividers with the curve but keep it straight) scribe a line for both the deck (beam?) and hull (frame?) Cut outside of this, and check for fit. File, plane, sand for a good fit and you've got one side of the problem solved. Pick up the bevels with a gage or do the template thing again (more a pain in the butt then necessary with accurate work) on the other side of the beam/frame assembly. Just like Dave said.

**Wild Wassa** · 03-22-2002, 02:15 AM

Hi Crip, I like your photographic links.

This guy is a cool America's Cup photographer, the Jubilee boats in the news portfolio, look good, and are wooden. Beautifully backlight. I have a feeling that, you like marine photography, I do.

http://www.martin-raget/eng/

Your marina looks amazing, we launch off a beach.

Warren.

[ 03-22-2002, 03:25 AM: Message edited by: Wild Wassa ]

**Crip** · 03-22-2002, 08:27 AM

Cheers for the tips fellas. Trying to stiffen up the decks on a (how do I put this nicely...damn, just have to come out with it) an old glass boat . There, I said it. Wish she were wooden, really I do, but we got her for free and there aren't many wooden boats here in Japan, free or otherwise. I know, I know, "You could always build one!" I did.
Anyway, just in case you're interested in sailing in Japan or seeing what I'm presently up to out here, click here.
Cheers also to Wild Wassa for the photo link (corrected here). Lovely stuff indeed.
btw. there must be some other methods of marking a knee out there... anyone else care to enlighten me?

Thanks again.

Crip

**Art Read** · 03-22-2002, 12:30 PM

That's pretty much how I did it... 'Cept I used stiff cardboard as a "pattern" to make my doorskin patterns. I found it easier to get "close" to the final shape with flexible cardboard up in those akward corners and then "proove" it with the doorskin before cutting out my knees with the good wood. Just make sure your pattern represents the "high" side of the bevel or you'll wind up with smaller knees than you intended! (DAMHIKT) Even after the knee itself is cut out from the pattern, you'll probably have to test fit it a few times and scribe the edges on both sides of the bevels to get a really good fit. I can't think of any any "shortcuts" to this other than careful lofting of the knees using the the actual, (as built) lines of the hull and deck for the section your knee will go in. Seems to me that would be more work than just working away at 'em bit by bit from a pattern. (Nice web site, BTW! LOVED your model of "Lyra"...)

[ 04-05-2002, 05:20 AM: Message edited by: Art Read ]

**Crip** · 03-23-2002, 12:05 AM

Thanks Art.
Glad you liked Lyra. Wish she was about 8 times bigger though...
btw. was that lovely photo taken in your boat?

Crip

**Art Read** · 03-23-2002, 02:55 AM

Yes, that's my boat. A shot from just before I screwed the plywood sub-decking home. I held the camera down between the deck frames just aft of the breasthook and aimed as best I could. No way I could fit in there!

**Crip** · 03-23-2002, 06:41 AM

C'mon Art, you can't leave us hanging there. Send a picture of the beauty from the outside!

Crip

**Art Read** · 03-23-2002, 11:37 AM

Well.... If you're gonna "twist my arm" about it....

**Dave Fleming** · 03-23-2002, 11:45 AM

Art, nice work, what design is it.
And more important when the hell is it goin' to hit the pristine waters of Puget Sound?

**Art Read** · 03-23-2002, 11:56 AM

Dave, she's a gaff-rigged, Dark Harbor 12 1/2 by B.B. Crowninshield from 1915. ("WoodenBoat" sells the plans.) I took a few "liberties" with the cockpit... The originals all had a little, "knee well", self-bailing type, but a lot of the of the existing boats have 'em opened up now, like I'm doing. As for the launch, well that's easy... Just as soon as I finish her!

(You can wade through the whole building proccess here if you want to kill some spare time...)

http://www.imagestation.com/album/pi..._all=1&start=1

[ 03-23-2002, 02:22 PM: Message edited by: Art Read ]

**Dave Fleming** · 03-23-2002, 02:32 PM

Art, as I just commented in the wood overlay thread I am impressed with your work.
It had to be 'fun' doing all that in one of those storage units.

And the shot of the plank going through that 'taiwan turkey' of a planer is something to see! That plank looks from the camera angle to be about 1/2 mile long......
You are one brave fellow to be cutting in the waterline freehand with no masking tape to guide your steady hand.
Mustn't have drunk any coffee that morning, eh?

**Art Read** · 03-26-2002, 04:29 AM

Well, I "cheated" a little on that bootstripe, Dave... I scribed a light grove along it with a little pull saw and a batten before I painted her. Besides, that's all just a quick, sealer coat and a chance to "see" what she'll look like when finished. The paint job doesn't look that good anymore, after all the beating around on her I've been doing since then... Besides, God knows, I'll probabably have to re-establish that waterline after I finally get her in the water!

My storage shed/boatshop actually works pretty well. Better than our garage, where she went together before I got her "turned over". Expensive, but I can make as much noise and mess as I like there... Running that plank, on the other hand (and a bunch of other ridiculously unweildy pieces) through that "lunchbox" planer WAS interesting though... I got pretty good at "jury rigging" some impromptu "infeed/outfeed" surfaces!

But thank you for the kind words. Means a lot to a lonely "tyro" struggling away all by himself...

**Crip** · 03-26-2002, 09:26 AM

Art!
really is art isn't it. Absolutely lovely, mate.
Went and had a look at your photo-journal too. Loads of fun had there, I'd wager. There's an email on it's way to you shortly. Hope you don't mind.

Cheers and congratulations.

Crip

**Bruce Hooke** · 03-26-2002, 01:29 PM

Pretty much all the methods I have seen for cutting parts to fit all the odd shaped spaces on boats come down to using some sort of a template (cardboard, door skin, masonite...) and something to pick off the actual shape and transfer it to the rough pattern and then reverse the process onto the stock (the material that needs to be shaped). My favorite tool for making this transfer is a flat piece of wood, say 1/8" x 3/8" by 6" (or to suit the size job at hand) with a point on one end:
__________________
__________________>

I clamp the template in place and then lay the pointed stick in place on the template with the tip touching the point I want to locate. I then trace along one edge and the end of the pointed stick. I can then reverse this process onto the wood that needs to be cut. The one weakness of this method is that if the template material has any significant thickness then the tip of the stick will be above the wood by a bit. I fix this but adding a step to the end of the stick that is the same thickness as the pattern material but of course this means that I need to clamp the pattern material a bit away from the surfaces I am trying to pick up. This also deals with the fact that in many cases the back of the template will be where the face of the finished wood should be so you really want to be picking stuff up at that plane anyway. What I don't like about the compass method is the bit about keeping the compass perpendicular to the surface since that leaves room for error.

On something like a knee where the bevel along each face is likely to be fairly consistent you can often get away with picking up the shape for one side and transferring that to the stock and then picking up the bevel and setting the bandsaw to cut that angle. One cut and if you have done everything right (and propitiated the right deities) it should fit right into place. And when it does work right it is very satisfying...

I know this sounds like a lot of work but with some practice it's not that bad and getting good at this sort of thing is one of the central skills for any real work on wooden boats (or wooden parts for other kinds of boats).

I have seen some very fancy templates with all sorts of clamping knobs and they may speed things up a little bit but it all comes down to the same principle and in the end the simple methods are the most versitile.

- Bruce

Thread: knees

Thread Tools

Display

Posting Permissions