The alternating fiberglass would be giving you more stability rather than strength. It's why aluminum, though less stiff and strong as steel, is used for airplane skins -- it's more stable at the same weight since it's thicker at that weight. In the end, alternating the glass might not be the lightest, but for a boat it might be cost-effective.
There is a section in FAR 23 that you could use. Landing loads and air load are about it. -- not to many planes fail at the tail -- flight loads aren't that high, and the span is not that large so there aren't any super-big bending moments introduced into the horizontal. It may be that on-the-ground handling loads (someone falling or leaning on the boom) would be more critical than even flight or landing loads. With a tail-dragger you could use 3-gs times the pilot weight and size for that, but if we put the pilot underneath the wing like the Arc, then even that load won't be particularly significant. It's hard to size something when the loads aren't obvious, or even particularly big...
--- On Sat, 3/17/12, Paul Hardy <This email address is being protected from spambots. You need JavaScript enabled to view it.> wrote:
From: Paul Hardy <This email address is being protected from spambots. You need JavaScript enabled to view it.>
Subject: Re: [Carbondragonbuildersandpilots] Re: CDII -fuselage
To: This email address is being protected from spambots. You need JavaScript enabled to view it.
Date: Saturday, March 17, 2012, 9:09 PM
Yes, without the rods it makes a very strong mast. I’ve heard people say just to use CF and others who call for alternating FG and CF. Since CF is much stiffer than FG I’m not sure what the benefit is unless it is just to build bulk more cheaply. For a tail boom I think I would leave out the FG and just go with CF or CF with rods.
