Anonymous wrote:Gulf of Triest this Sommer, 18 Kn gusting 24, little steep waves 0.4 m. I started conservatively to avoid too much stress on her 40 years hold spar. With 4 panels up we were making poor progress upwind. I wondered if the boat was under canvassed so I raised the 5th and the 6th panel. The boat heeled to 15 degrees, stiffened up and started to go upwind properly. The mast bended at any gust.
I think every boat has a heel angle that tells when canvas is maxed out. Mine is at about 10 degrees, the previous owner says the boat he owned before this one was happy at 15 degrees. So it sounds like you were probably canvased correctly. With my boat, 10 degrees will get me up to hull speed, so no need to add canvas but my boat is probably heavier and stiffer.
My alloy mast is a folding one. The dimensions are 10 cm diameter at the base and 6 cm the top. The joint between the
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measures 10 cm at the base and 6 cm at the top. Hasler itself developed the rig of the KF 20+ and sailed his own KF 20+ "Pilmer" upwind in F6-7 "in steep breaking sea" (see article below) without breaking the rig. Surprisingly, according to PJR the mast for a Kingfisher 20+ with a 21 sqm sail should measure 20cm at the base!
I think that is what a lot of people are getting at, the PJR is well over built. I think part of the difference is wood vs. aluminum. Well, that is not quite right, woods strength as quite well known but wood is in general, no uniform for any one kind of wood. It depends on where it is grown, how it is dried, how or if it is glued together, where the knots are, etc. PJR does most of it's calculations based on wood with, I would imagine, extra strength built in to compensate for wood flaws. (or maybe extra strength just because it is someone else's boat and they feel responsible for it)
I wonder how "alarmingly" is really a thin bending mast on a coastal cruising boat...
:) That is why I have been quoting that word, 'cause I don't know.
A thin mast would mean less parasitic drag on the starboard tack and less sail distortion on the port tack (am I right?) and while bending it could absorb gusts smoothly.
As with anyone, I want as little windage as I can get but a broken mast has no windage at all.
Could be a thin mast made of carbon fibre a good solution for a coastal cruising boat?
I trust my carbon fibre skills as somewhat less trustworthy than my wood butchery skills :P
Aluminum, with no welding or other fastenings, gives me something that is the least likely for me to mess up.
P.S 2: sorry for parasitizing this thread again :)
I think by now we have T-shirts for that.