>>So, the vertical planks would have an elliptical shape (narrower near the ends),


No, just straight but with rounded corners.


>>and the alum strips would be constant width and thickness? Maybe 2" x .25" alum strips? A max width of the side planks of 6" to 8"?

Are you still serious with this approach ? If so then I will run the math on it and try to get you the best balance between weight and stiffness.


>>Aluminum strips on the 3 edges?

>This question refered to the original T shape.

I don't think the side edges need any alyu. Just top and bottom will work. However if you want more side-to side-stiffness then the much efficient weight setup would indeed be to replace the alu strip on the top by two on each side (with same combined crosssection area)


>>Type of aluminum alloy?

Anyalu you can buy at your local hardware store will be fine. Anodising is not really necessary. Most commonly available alu types are of 6061, 6005 and comparable alloys anyway. There is not much difference between these alloys at all.


>>The main has a luff of 34', foot of 11', square top. Currently running 10 to 1 mainsheet, I think about 12 to 1.

All right, I don't oceans of time so which setup is preferred by you. Round alu tube or T-composite setup. If you want I will run the numbers on one of these setups this weekend.



>>Thanks Wouter, and others, I'm enjoying this education.


Well that is the whole intention !

Wouter