First Cedar Strip Canoe

[pbrown]

Hello all,

I am building a 16' Prospector and am a first timer. I am working on the stems and getting the batten boards. My questions are as follows:

- Some literature I have read suggested using softwood inner stems and hardwood outers with varying dimensions. Some say 3/4" x 3/4" inners, 3/4" x 7/8" outers and others say inner and outer 3/4" x 7/8". Dimensionally, the literature says to shave the bow and stern down to 1/8" on the inners. 1/4"+1/4+1/8"=5/8" Why does the outer stem have to be 7/8"? There are also discrepencies on using softwood inners. So far I have laminated softwood 3/4"x3/4" inners, and 3/4"x7/8" ash outers ready to bend. Before I go further is there any tips on stems? What sizes and materials to be used.

- I like the look of 7/8"x1/4" batens. Less glue, etc., but are there advantages in using 3/4"x1/4"?

Thanks,
Phil

[Doug]

Softwood is generally a lighter wood and not as durable.
After a few portages; the weight of your canoe weighs not only on your shoulders but on your mind as well.
Ash (or a hardwood) is generally heavier and more durable.
Your call.

The sizes should be given in the instructions.

"I like the look of 7/8"x1/4" batens. Less glue, etc., but are there advantages in using 3/4"x1/4""
Are you refering to the cedar strips?
3/4" strips will give a better "rounding" of the hull.
You might find that you will sand the edges a little to much, in the end.
Causing a thinning in the hull?


All the best,
Doug

[Glen Smith]

For inner stems, softwood is fine. Ineers normally 3/4" X 3/4", outers should be a hardwood and 3/4" X 7/8" is quite normal. You can get by with 3/4" X 3/4" outers if the laminations are well aligned during the glue-up procedure. Making them 7/8" wide gives you some elbow room if the alignment is off.

As Doug said, using 1/4" X 3/4" strips will make it a bit easier to strip around the turn of the bilge but a lot of suppliers sell 1/4" X 7/8" strips so it is doable.

The Prospector has a station 0 girth (measured from sheer-line down to keel-line and back up to the opposite sheer-line) of about 55". Using 7/8" B&C strips (face width 3/4") you will require 74 strips. Using 3/4" strips (face width 5/8") you will need 88 strips. So, that is 14 strips more to glue in place.

[Denis]

Are you using one piece stems or laminating your stems using quarter inch material? If laminating I would suggest they be steamed and bent first, allowed to dry then glued up.

Denis from Lakefield Ontario

[pbrown]

Thanks for the advice guys. I have the answers I need. I am going with laminated 3/4"x3/4" softwood inners and 3/4"x7/8" ash outers. I will be portaging this canoe. I am also going to use 1/4"x3/4" strips for better hull integrity. I am considering using Titebond III on the stem laminations. It is waterproof, and has the overall appearance of wood glue. Titebond II is water resistent. Titebond I is regular wood glue. No mixing and a 30 minute open time. Can anyone see why I should not use this on the stems over epoxy?

[Doug]

pbrown,
"I am considering using Titebond III on the stem laminations"

You may want to consider using epoxy on the stems.


Doug

[davidb54321]

pbrown, I am building a Prospector at the moment also. I made my inner stems from 3/4" cedar, and my outers of 7/8"Ash. My math works like yours....ie 1/4+1/4+1/8=5/8, however, this only works if all the pieces are parallel. When the angles between the pieces increase, the faces of the strips become wider, Thus the extra width suggested. The Prospector stem is quite narrow along the front edge until you get down along the keel area, so you don't need mold stock any thicker than 1/2" for the stem molds or you will just be removing it to plank up the stem.

[garypete]

David,

Titebond III works well for the laminated stems, having good body for gap filling, and being waterproof. I've used both Titebond III and epoxy for stems, and epoxy is much slower to cure and messier. And since the stems on the canoe will be totally encased in epoxy, waterproof qualities are really not an issue.

If you're using light-colored ash for the laminations, be aware that Titebond III dries to a dark brown and the glue joint will stand out in the light wood. For light wood, consider the water-resistant Titebond II which dries to a light ten color. I used Titebond III on western red cedar stem laminations, and the color match was perfect. On some white cedar stems, the glue lines were pretty obvious.

Gary

[pbrown]

I have made an extra practise inner stem. I have began to work it using a block plane and spoke shave. I read in the canoe craft book not to work too far ahead, but because it is a practise stem I have. I am finding that to get the front down to 1/8" that I am having to remove some of the mold that the stem sits on. I am using a shortened strip to find the correct angle. As I move the stem to the bottom of the canoe it does not seem possible to have the strip touch the last station mold and meet with the stem nicely. I am going to check the last station mold against the pattern, but if it is correct I would say I am at a loss of how it will work. Are there any tips or tricks to shaping the stem. The other problem I am having is that it is not possible to use a clamp to hold the stem, but if I glue some strips on first it seems they will get in the way for shaving as I go.

Any suggestions.

[Glen Smith]

John Michne has some excellent advice on shaping the inner stems on his website: http://www.michneboat.com/Shaping%20the%20Stems.htm. Cutting into the stem mold is normal if the material is over 1/2" thick. I don't see why you can't hold the stem in place with C-clamps but there are other methods.

[STINGRAY8T]

PB, Try drilling 1 1/4" holes thrugh your stem mold. That way you can use c-clamps to hold your stem to the mold. Don't let the holes get to close to the edge of the mold for strength purposes. I'll defer to those with more experience for your other problem.

[pbrown]

I have the 1 1/4" holes in the mold, but the c-clamps get in the way of the block plane. I am sure with patients I can do it, but was looking for any tips that only experience can bring.

[davidb54321]

pbrown,

I dealt with the same things with my Prospector. I used John Michne's methods on the stems.(do a search on this forum or Google for John) I used some finish nails to hold the stem to the stem mold while shaping and attaching strips. It worked great and no clamps in the way.

Are you talking about the half-molds that are giving you fit problems along the keel? Those molds should come up to the bottom edge of the stem/stem molds. When you get to that step in the planking and bevel the stem, the planks will lie quite well.

Be extra dilligent at the stem ends of the planks. The only place I really had to fill any gaps on my hull was on the ends near the stems. Get them tight when you put them on and save time later.

I used 3/4 x 3/4 cedar stems inside and 7/8 ash outers using 1/4" laminations and it worked out fine.
I used 1/2 inch material for my molds and some of it did get removed when beveling the stems. This is OK. Just be sure to replace the tape that gets sanded away before you glue on the plank(This assumes you use John Michne's methods and sanding sticks which I highly recommend)

I had trouble using the plane and spokeshave for the rolling bevel, but used them well for the major stock removal prior to using the sanding stick.

[STINGRAY8T]

PB, I didn't use a plane to shape my stems. I used a file that I bought from Newfound woodworks. It looks like a bunch of hacksaw blades. One side is coarse, one side is smooth. Worked great, very fast. It allows you to get into very small areas and leaves a great service for glue or epoxt. I used it to shape the outer stems as well. Check it out. You'll love it.

[Glen Smith]

My stem molds and inner stems are always about 1.5 to 2" higher than needed to get the sheerline above the strongback. I drill a clearance hole though the inner stems and a pilot hole in the stem mold in this excess area and I drive in a wood screw to hold that end of the inner stems in place. I use a few C-clamps on the upper portion of the inner stems and by the time they have to be removed, I have enough strips installed to hold the inner stems steady. You can see the screw in the bottom of the stem in this photo and the C-clamps in the upper portion: