Kepnutz (or anyone else experimenting with boombats),
You mentioned in your posts about possibly using a fishing blank. Did you ever try one? I was looking for a rod with variable thickness that might work better than the 5/16 inch fiberglass rod I currently am using, as I think that is just a little stiff for upwind sailing, as the sail doesn't curve at the bottom. Boats with real booms keep the sail straight on the bottom, but I wasn't sure with this sail shape is that is preferred...there isn't much sail to have any inefficiencies (unless the stiff boom helps the air flow in other ways, which would make the rest of my post moot.)
I thought a variable stiff rod might give the sail better shape sailing upwind (putting the tip toward the mast, allowing more curve near the mast), but give the sail stiffness to keep the sail out more when going downwind because the latter half of the rod would be rather stiff.
I'm shooting for the shape shown in the article:
http://www.arvelgentry.com/techs/A%20Re ... Theory.pdf
which shows an "ideal" shape of main and jib sail config as the following:
Sailing with the 5/16" rod (below in 6 mph winds), the rod stayed straight instead of allowing any bend.
I have three examples below for rods:
The first is my existing 5/16 inch rod under pressure ($7)
(Too stiff? There isn't much shape near the tip)
The next example is a 6 foot solid fiberglass fishing rod ($11):
too much bend on the tip?
Next is a whip that I bought at Fleet Farm for eight dollars:
Is this one just right?
Unless someone else had already experimented with this, I think I'm going to unravel the threads from the whip to thin it out and try it in the sail. I'll keep it a little long, and if it's too flexible at the tip I can cut the tip off to stiffen it up a little more.
Unfortunately I probably won't be on the water for another couple weeks at the earliest.