Bagged RES wing

[komar]

I'd like to make bagged wing for my new RES (actualy only RE) glider. Wingspan will be 2600 mm (102 in), area about 55 dm^2 (850 sq in).
Construction will be center panel with detachable tips. What skin layup will you recomend? I want to use only glass, since kevlar or carbon is not easy to buy and is expensive.
My second question is about wing section. I'm going to use AG24 (root) -> AG25 -> AG26 -> AG 27 (tip). Any comments on that?
And third one - what dihedral angles do you recommend? Simple V, two breaks or even three breaks (like BubbleDancer). I prefere smal angle in center and bigger for tips. I hope you understand what I mean.

--Komar

[lincoln]

You might look at the original Allegro (not the Allegro Lite) plans at charlesriverrc.org. One, two, and three layers of 1.5 oz glass.

I once bagged a wing with 60 lb kraft paper. Very tough stuff, and easy to work with. Was a hlg wing, tho, and I should have used 40 lb kraft paper. As it was, came out about 150 grams. As I recall, you spread epoxy, wait 5 minutes, the squeegee it off and do the other side. Bags on easily. Much easier to handle than glass. It doesn't "squirm" on you. I stepped on this wing (barefoot) by accident, and all I got was an easily fixed crease.

I am told a prominent slope flyer out west used to use this material.

Once did some skin stiffness tests and found the paper to be competitive with glass.

[DACeller]

For information purposes, could you please be more specific on the 'kraft' paper? Brand, availability, etc.

[atjurhs]

Komar,

You might want to check out my build thread on a VERY similar project, almost exactly the same.

I learned a lot of lessons on the build that might help you from making similar mistakes.

http://www.rcgroups.com/forums/showthread.php?t=632290

Todd

[lincoln]

For information purposes, could you please be more specific on the 'kraft' paper? Brand, availability, etc.
I don't know about brand. I think it's kind of a commodity. I got mine at a chain drugstore. If you search on line you can find many different weights of it for packing. If you are really cheap and want a small, heavy slope glider, steal new paper bags from your grocer. You also can often see it used to wrap packages, or at least it used to be common for that.

I suspect 60 lb would have been adequate for a much larger wing. Maybe 30 or 40 lb would have been ok for hlg/dlg.

You want to avoid anything funny like waxed, bleached, etc. Just plain brown kraft paper. Like you see in paper grocery bags, and paper lunch bags.

This stuff is dirt cheap. I think you can get a foot wide roll several hundred feet long for $10 or $20.

Now you know about as much about it as I know.