: I'm working on a skin-on-frame canoe of my own design, and I have a
: couple questions:

: 1) Stiffening the frame with some kind of roving/twine:
: I'm probably going to use some kind of twine or roving to stiffen
: the frame the same way they do for the "aerolite"
: boats from Platt Monfort.
: Those I know use kevlar roving, but I'm wondering if that's really
: necessary - I could use polyester twine as well (stretchier, not
: as strong, but a lot cheaper). I'm also wondering about the
: durability of the kevlar roving. I plan on polyurethaning the
: frame with exterior poly, would that give me extra toughness in
: the roving? Or be a bad idea for some unforeseen reason?

: 2) Dealing with skinning around the stems:
: I recently skinned a kayak with polyester and due to my inexpert
: sewing technique ended up with a lot of pull holes. This wasn't
: a huge deal, I gooped them with clear sealant. There are no pull
: holes below the waterline because I didn't have to stich around
: the stems - I used Jeff Horton's (kudzu) technique of stitching
: from the center out towards the stems.

: On the canoe however, the stems are too steep for me to be able to
: get away with just pulling up the fabric, and there will have to
: be some slitting/cutting/stitching/stapling/affixing around the
: stems. My impression is that on the aerolite boats, the stem
: fabric is just cut to fit and heat-taped to the stem, and then
: some kind of tape is applied to the outside of the stem.

: Could I just staple the fabric to the stem and put a rub strip to
: hide the staples and protect the stem? Should I add some kind of
: fabric tape over the stem? I'm thinking: bias-cut a strip big
: enough, saturate it with polyurethane, and just plop it on the
: stem when I'm sealing the boat.

: Thanks!

If you're making an extreme ultralight boat, like Monfort's, then the roving will help, otherwise it's not needed. Kevlar has virtually zero stretch, polyester has about 15%, won't do much of anything except add weight.

Stapling is no big deal, if the staples are driven flush, after they are put in done with a hammer, they are really difficult to see.

If you're using polyester fabric to cover the boat, even the pre-shrunk fabric will shrink a bit with heat and most of the fabric used for covering is unshrunk so will shrink considerably with heat. A clothes iron is lots safer than trying to use a heat gun and you have more control. Pretty easy to cover most boat shapes with heat shrunk fabric.

Bill H.