Sion,
I did my strips with 3/8 diameter cutters and it worked just fine. I had several sizes available so I picked the set that gave the results I liked best. For flat joints I didn't note any real difference. On curves the pieces seemed to fit a little better. My preference has nothing to do with fragile edges. I think this will be a problem no matter the diameter of the cutter. They aren't that fragile and you learn to handle the strips carefully to minimize damage.

Accurate milling of the strips is pretty easy if you set up a good fixture. Someone posted a picture of a clever setup that involved two routers. I used a With my setup, the cove is cut with one pass then the bead is cut with another. Setup is easy and I don't mind milling a dozen strips at once. Also, I can not cut the cove and switch to rolling bevel.

1/4 inch was probably chosen to match the material thickness most commonly used.
Mark

: I'm strip building an expedition single and I have very little practical
: experience with wood working tools. So far, I've built the stands and the
: box beam and I'm working on cutting out the forms. Looking ahead to the
: next steps, I've priced out some Cedar for the strips. I intend to do the
: milling of 10' 2x4s or 2x6s to save money. While reading a couple of
: different resources, (Nick Schade, The Strip Built Sea Kayak, Canoe Craft
: by Ted Moores and the Internet), I notice that the cove and bead
: dimensions are given to match the wood diameter - 1/4". I also
: noticed that the cove edges are often called thin and fragile. Also, I
: wondered about the ability to precisely mill 1/4" coves in strips
: which will be dimensionally variable due to my inexpert handling and
: cutting. I wondered if the cove could be made larger, say 5/16" or
: 3/8" which might have the following advantages: 1) The cove edges
: will be shorter and thicker and therefore stronger
: 2) The larger radius might allow a bit more latitude for dimensional
: variability in the strip thickness when cutting the cove.
: 3) The larger bead and cove may not fit together as tightly as a 1/4"
: joint, but the joint may still fit tighter than a lap joint.

: Can anyone save me time by telling me why the 1/4" cove was selected,
: and whether a larger cove and bead is an option?

: Thanks
: Sion