Stripping techniques

[cs]

Okay, I've been studying different stripping techniques and have some questions before I get started. I've been looking at Daved Hazen's "Strippers ..."

The first technique he talks about is doing the football first and I'm not going that route. The next one he talks about is starting at the assumed waterline and stripping from there. This is similar to the way I want to go. Neither of these methods really cover what to do at the shear line, or else I have missed it in my reading.

What I want to do is to start a strip that follows the shear line. The next strip will be tangent to that strip, but run parrallel to the assumed waterline. This strip will be what all the other strips are based on. The shear line strip will give me something to work to.

Does this sound right?

http://a5.cpimg.com/image/EB/FF/7983595-6f35-022E015E-.jpg

Chad

[Ian McColgin]

Best to start at the top. Then pants. Then . . .

But seriously, try drawing the planking lines a bit. If she's well designed for stripping the height at bow and stern matches the increased girth amidships and nice strips can be laid from the gunnel to somewhere about the turn of the bilge.

[cs]

Ian:

Are saying to just start laying my strips at what I've called the shear line and by the time the get around to the assumed waterline they will start running straight? Am I getting my terms wrong?

I'm using a higher stern and bow than a normal (for looks) so the gunnel has a little more curve to it. Does this make a difference?

Chad

[Ian McColgin]

It does make a difference, but perhaps not intolerable.

Yep, it should work if you just lay 'em along the sheer line, as you have it labled.

If you have the hull lines, loft the station sections nice a full size. Mark the planks on each section and see if it looks like it will fare ok.

If the bow is too high, the planking will never level out, so to speak, as it approaches the water line. If the bow is too low, it'll look hogged.

The strippers I've seen and helped with were carefully thought out in this matter and you deviate at your own peril. But then, deviance is what stripping is all about . . .

[cs]

Ian:

Once I get the stations on the strongback I will lay out the first strip as you say and look at it and see where to go from there. BTW the plans included three different stem designs. One for tracking, one for speed and the "torpedo" style for style. The torpedo style is the one I'm using.

Thanks

Chad

[Todd Bradshaw]

As shown in your drawing, I can see two potential problems that you might want to avoid. The first is that filling the space between the sheer strip and the level strip is going to require some really long tapered strips which are tedious to shape. You're trying to fill an enclosed, wedge-shaped area with straight stock, which means a lot of extra work. The second is that visually, the sweeping outwale/sheer-line makes a very strong statement. A level strip that nearly meets the outwale in the center of the boat and then continues out level to the ends often tends to look hogged. It just isn't strong enough, visually, to establish itself as level and winds-up looking like the ends sag - even if it's perfectly straight. If you look at the old wood/canvas canoes with fancy, two-tone paint jobs, they normally drop the level line down a bit (2"-4" below the gunwale at midships) which helps avoid the sagging look.

From a construction point of view, the sheer line strip doesn't really add anything except work. It's generally easier on a boat with a sweeping sheer to extend the forms near the ends a bit in the gunwale area, strip a little past the proposed sheer line, sand it, glass it - inside and out, turn the boat upright and then go in with a batten to mark and trim the sheer line - or rough cut it and do the final adjustment by sanding it down flush after the gunwales are installed.

You can lay things out on paper, but it may be better to do it (or at least to do a final check before stripping) with a few temporary strips right on the forms. This gives you both a visual idea (though upside-down) what the pattern looks like and, more importantly, tells you how much twist, curve and edge-set the strips will need to follow the shape from stem to stem. It's a bad feeling when you have half a canoe stripped-up and they start snapping or pulling away from the forms because your planking layout exceeds the capability of the strips to follow the shape. This can be even more of a problem if you're building without staples, since your ability to hold strips down tight on the forms and up against each other may be limited by less secure and/or more intricate clamping procedures.

In any case, do not rely on the canoe's cross section girth to solve the problem by itself. It is very rare that you can just start stripping and have everything work out peachy. Pre-establishing the pattern, checking it with battens and putting little tick-marks on forms so that you can keep track of how close you're staying to the plan while you strip are all generally worth the time on your first boat.

[Sailman58]

When I did my stripper, I started with a strip at the shear amidships and carried it as high as I could at the ends without edgeset. Then I stripped down to the bottom where I changed to parallel strips with tapered ends. Then I used short strips to fill up to the top of the stem. I finally trimmed the shearline after glassing.

Ron