>>> While I agree with Jim regarding comparitive strength of basswood vs > balsa, I question the "science" behind the idea that cedar > doesn't cut it in comparison to redwood. Any board will stress out and > even break in certain conditions. An old photo of Peter Cole carrying > pieces of a broken board with numerous thick stringers comes to mind. > Chouinard of Patagonia did actual lab tests with a calibrated device and > samples of different foam, stringer, and glass combinations. This is the > only scientific study of this type that I'm aware of. The statement that > Jim makes is based on rather limited experience with a limited number of > samples and uncontrolled conditions. Amongst samples of the same species > of wood (even Jim makes this statement re: balsa) you will find a huge > variation in quality, grain, density, etc. Even (especially)the way it is > sawn is a factor. We'd all like to get clear, straight grained, vertically > sawn stringer material but that is not always the case. I've cut into > stringers with knots, bizarre grain direction changes, etc. Go to any > lumber yard and see for yourself. "Redwood" for instance is > available in a number of grades - some is clear heartwood, some is shitty, > knotty, soft stuff that doesn't even compare. I'm not knocking Jim (I > respect his experience, knowledge and board making skills) just > questioning the conclusions he has drawn. (I think I'm overdue for my next > "S.A." meeting...) Ahhh yes, my scientific experiments with more than several different selections of Western Cedar in uncontrolled conditions (i:e. the surf, which is always uncontrolled) taught me not to rely on what I THINK will be sufficient for strength, but to use enough to keep the boards from flexing. They were noodley before glassing and I SHOULD have taken that as a clue, now mind you they didn't break, but had a thousand stress lines. The Patigonias are EPS blanks and glassed with epoxy, I think regular boards should be done in epoxy, but it is such a pain in the ass to build epoxies, using all epoxy, that production would be next to nil. http://[email protected]
>>> That's good to know Jim, but what should one do if they love the look of a > three stringer board with redwood offsets (if there is any left) and red > cedar sucks? The Cedar will do, but as in any wood it needs to be wide enough to keep the blank rigid. The standard 3- 1/8" stringers is just a tad shy of what is needed, say a 5/16" or 3/8" center with 1/8" offsets. I have been working on experimental stringers, one is the "springer", an all laminate of 1/2" strips, tapered at the ends and glued over a rocker form, like the laminated beams in churches and auditoriums. A purely one off system not intened for mass production and the X-Band, a T-Band of wood glued edge to edge at a 60 degree angle, split off from the sheet and then reversed so that the wood is counter crossed. I have the wood glued, but haven't made up the sandwiches of it yet. The drawback I see is that in one direction I will be planing against the grain, but it SHOULD be really stiff. As you can tell I don't like flexy boards, I think that when they flex enough to tell, the rocker changes and the board gets unpredictable as to where it will wind up in the turn. I've had a number of boards, that after riding them long enough to have them delaminate on the decks, that the became soft through the turns and didn't have the punch that they had previously. IF you can't dazzle them with brilliance, baffle them with bullshit. That's what I say. http://[email protected]
To be fair, Patagonia uses multiple stringer set ups in a lot of their boards. I was simply sticking up for what I felt was a legitimate effort by Chouinard to identify the best materials. Hey - the surf forecasts are looking GOOD! I hope everybody gets their share and then some this week.
>>> While I agree with Jim regarding comparitive strength of basswood vs > balsa, I question the "science" behind the idea that cedar > doesn't cut it in comparison to redwood. Any board will stress out and > even break in certain conditions. An old photo of Peter Cole carrying > pieces of a broken board with numerous thick stringers comes to mind. > Chouinard of Patagonia did actual lab tests with a calibrated device and > samples of different foam, stringer, and glass combinations. This is the > only scientific study of this type that I'm aware of. The statement that > Jim makes is based on rather limited experience with a limited number of > samples and uncontrolled conditions. Amongst samples of the same species > of wood (even Jim makes this statement re: balsa) you will find a huge > variation in quality, grain, density, etc. Even (especially)the way it is > sawn is a factor. We'd all like to get clear, straight grained, vertically > sawn stringer material but that is not always the case. I've cut into > stringers with knots, bizarre grain direction changes, etc. Go to any > lumber yard and see for yourself. "Redwood" for instance is > available in a number of grades - some is clear heartwood, some is shitty, > knotty, soft stuff that doesn't even compare. I'm not knocking Jim (I > respect his experience, knowledge and board making skills) just > questioning the conclusions he has drawn. (I think I'm overdue for my next > "S.A." meeting...) Ahhh yes, my scientific experiments with more than several different selections of Western Cedar in uncontrolled conditions (i:e. the surf, which is always uncontrolled) taught me not to rely on what I THINK will be sufficient for strength, but to use enough to keep the boards from flexing. They were noodley before glassing and I SHOULD have taken that as a clue, now mind you they didn't break, but had a thousand stress lines. The Patigonias are EPS blanks and glassed with epoxy, I think regular boards should be done in epoxy, but it is such a pain in the ass to build epoxies, using all epoxy, that production would be next to nil. http://[email protected]
>>> That's good to know Jim, but what should one do if they love the look of a > three stringer board with redwood offsets (if there is any left) and red > cedar sucks? The Cedar will do, but as in any wood it needs to be wide enough to keep the blank rigid. The standard 3- 1/8" stringers is just a tad shy of what is needed, say a 5/16" or 3/8" center with 1/8" offsets. I have been working on experimental stringers, one is the "springer", an all laminate of 1/2" strips, tapered at the ends and glued over a rocker form, like the laminated beams in churches and auditoriums. A purely one off system not intened for mass production and the X-Band, a T-Band of wood glued edge to edge at a 60 degree angle, split off from the sheet and then reversed so that the wood is counter crossed. I have the wood glued, but haven't made up the sandwiches of it yet. The drawback I see is that in one direction I will be planing against the grain, but it SHOULD be really stiff. As you can tell I don't like flexy boards, I think that when they flex enough to tell, the rocker changes and the board gets unpredictable as to where it will wind up in the turn. I've had a number of boards, that after riding them long enough to have them delaminate on the decks, that the became soft through the turns and didn't have the punch that they had previously. IF you can't dazzle them with brilliance, baffle them with bullshit. That's what I say. http://[email protected]
To be fair, Patagonia uses multiple stringer set ups in a lot of their boards. I was simply sticking up for what I felt was a legitimate effort by Chouinard to identify the best materials. Hey - the surf forecasts are looking GOOD! I hope everybody gets their share and then some this week.
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