This crow tastes terrible.

Let me just start by saying I'm not trying to walk the fence and be on both sides. I'm just trying to search for the truth in other methods and maybe should have done the analysis before posting on the web. I should talk it out with myself first instead of rambling out loud in front of you.

Don't get me wrong, I do believe in the 2 plies of 6 oz method as I stated earlier. It has been time tested and real world tests is part of where the basis for Engineering comes from. I was trying to compare using 2 layers of 6oz as a base for good design, with other layups and see if there is a better way to get the same strength and less weight.

I have taken an advanced composite analysis class and done the ABD matrix, and all the other stuff needed to do an analysis. As those who have done it before know, it's a real pain in the arse. It has been about 3 years since I've done it and I really don't have the time to bone up on it again (I am trying to build a kayak you know).

Most of what I said below I agree with, but I did a quick estimate and I think I'd be coming up short from the industry standard by using 3 plies of 3 oz instead of 2 plies of 6 oz. Maybe I would need to use 4 plies of 3oz to get the strength, but then I'd have the same weight at a higher cost.

I was going to post the above message when I got home from work anyway, but I got an E-mail from one of our many readers (who will remain nameless) that said I "sold out". I'm mentioning it here not to air my dirty laundry, but because I think this is something that all should hear. Is all of this really my side vs. their side? I said before that I believe the industry standard is just fine, but if we are to search for something better then tempers get heated up. I believe that Nick, and the rest are doing a great job, but If I say that George may be right on this point or that then I'm switching sides. Is that being open minded? Come on, we're all here to try to build a better kayak. None of us is the smartest or has the best ideas, but we all have some good ones. Believe me, I've stolen a lot of good ideas from this board and maybe contributed one or two.

George, the attitude on this board is partly your fault because you've short answered people so many times and pissed them off so much that many are not open to looking at ANY ideas from your point of view.

I think that it's time for me to step away from this thread as the emotions are getting in the way of being able to objectively look at any other ideas.

I'll just use 6oz cloth. Heaven forbid I LOOK AT any alternatives.

The following statements I still believe to be true.

: Just a SWAG with no analysis (number crunching) what so ever, but I'll go
: with the (2) 3 oz over the (1) 6 oz PROVIDED that the (2) 3 oz are layed
: up at 0/90 and +45/-45. The one thing I never hear any talk about is that
: you get fibers in more directions for out of plane loads.

: The 6oz would be stronger if you laid it up with the cloth at 0/90 and then
: loaded the panel by supporting it at the ends and pushing down in the
: middle (with the direction of the 0 fibers). But what if the 6oz cloth
: were at +45/-45 to the load. Not very strong at all.

: Take a piece of cloth and pull in the direction of strands (STRONG), then
: pull in the other direction at 90 degrees to the first (STRONG). Now pull
: at 45 degrees (weak). It's the same in compression. Of course you can't
: push on the cloth (like pushing on a rope), that's one of the jobs of the
: resin. It stabilizes the cloth so it can take compression. In compression
: the resin would be entirely in compression, and if the fibers were at an
: angle they would be in compression and bending which is much higher stress
: on the fibers.

: The thing about your kayak hitting a rock is that it is not loaded like a
: board held at each end and loaded in the middle, it's loaded more like if
: the board were held on all 4 sides and loaded in the middle (actually more
: like disk supported all around with a load in the middle, like a truck
: driving over a round manhole cover). The fibers in the +45/-45 direction
: help to take the load that are out of plain to the fibers in the 0/90
: direction and vice versa.

: It's like a piece of plywood versus a board of the same thickness. Hold them
: on 2 ends (the strong direction of the board) and load them in the middle
: and the board should win. Hold them on all 4 sides, or in the bad grain
: direction of the board, and the plywood should win.

: I am not saying that the 6oz cloth layups are bad (especially since they have
: been proven by years of tests on the water), I myself even used it on the
: deck. They are probably more than adequate to do the job. I am saying that
: there are stronger, lighter (but more expensive) layups than the standard
: 6oz.

: By the way, satin weave is better than plain weave because there are a lot
: more fibers that are not bent so they can take the compression better.

REMOVE THIS PARAGRAPH SINCE IT WOULD TAKE 12oz (4 @ 3oz), NOT 9oz (3 @ 3oz) AND PROBABLY BE STRONGER, BUT THE PRICE JUST WENT UP FOR VERY LITTLE GAIN. ": My guess would be (again no analysis) that if you put (1) layer of 3 oz at
: 0/90, (1) 3oz at 30/-60 and (1) layer 60/-30 you would have a stronger
: layup (loaded with support all the way around) than (1) 6oz at 0/90 and
: (1) 6oz at +45/-45. You'd also have only 9 oz of cloth rather than 12 oz."

: Lesson for George: See I am giving my opinion of which I may believe I am
: right, but I am not saying (YOU ARE WRONG!!!). To do that, I should prove
: it with numbers and provide reasoning for any assumptions, not "I'm
: right, now you go look at these books and prove it to me".

: How's all of my info above, but then again, you got what you paid for.

: Dale