Fred,
A foam core would work but filler would be more solid and resist those
high heels.
In my answer to Ron Parigoris on my experiment:
My use has been with standard 7725 Bid, two layers on the bias. That is
the strands run at 45 degrees to the wing root rib.
To stiffen the area, once the fillet is on and filled, then add layers
on top, peel ply, then fill again. You can use flox as the filler but
expand cell will do. Figure it this way. The filler is now another
core material. That makes a very stiff core and will aid in making the
elasticity lower. If you add carbon fiber rather than E glass, it will
make it even more stiffer as the carbon will make the layer nearly
rigid..
I do not know without building a panel if the carbon is more effective.
Flox and carbon would prevent a Stilleto heel from going through the
skin, but at what cost in weight. A layer of carbon then filler then
more carbon would be super hard, very ridged and cost about another $200
in material...
This only need be done for the guy who puts weight ahead of the spar.
Behind the spar is OK for the tail dragger crowd. Just don't put your
foot beyond the spar.
Bud.
----- Original Message -----
From: Fred Klein<mailto:fklein@orcasonline.com>
To: europa-list@matronics.com<mailto:europa-list@matronics.com>
Sent: Monday, February 02, 2009 11:13 AM
Subject: Re: Europa-List: Wing Walk Tape
On Feb 2, 2009, at 7:02 AM, ALAN YERLY wrote:
the forward D tube of the wing is foam and glass sandwich only
supported by the root rib and the next rib is nearly 16 inches further
outboard. I'm afraid the flexing of this area means any filler in that
area will crack. The depth of the filler is quite thick here due to the
transition from the wing fillet. That is why I have started to add
glass layers over the filler from the fillet outboard to try to stiffen
this area.
Bud,
After following this thread, I'm tempted to suggest another possible
solution.
I have some 1/8 inch Lastafoam; after sanding off the gelcoat, I could
bond a piece say 6 inches wide and say 10 inches (fore and aft) onto the
top of the D tube abutting the edge of the wing root fairing...then
sanding it down (inboard) level with the thickness of the fairing and
carefully feathering it down to nothing (outboard)...this would avoid
excessive depth of filler...then cover what's left of the foam w/ some
FG, say 2 layers of BID lapping over the wing root fairing.
Caution, of course, should be observed for any alteration of the
airfoil, but conceptually, one would strive to maintain what results
---From the use of filler in this area...merely substituting foam for
filler.
Your reaction?
Fred
PS: I appreciated your post a while back which cautioned against any
attempts to close the trim tab control arm slots in the fuselage, saving
me some time and potential grief...thanks!
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