Flap gap seals made from vertical venitian blinds

[One's Too Many]

A buddy of mine is contemplating making his flap gap seals from the
thin PVC plastic blades salvaged from a set of vertical venitian
blinds. The blades are very thin and flexible enough, and more than
ample long enough, and are 3" wide, which will need trimmed down to
about 2.5" wide so they don't stick too far aft into the path of the
flaps' travel. The issue is how to attach them to the underside of the
fiberglass wing effectively without making a mess of things. You can't
really glue them since they're PVC and most glues don't stick so
well. How about using some 3M double-sided thin foam mounting tape 1"
wide along the full length and stick that to the underside of the wing
in front of the flap gap, and then seal the leading edge of the PVC
blade to the underside wing with a 1.5" wide strip clear vinyl 3M part
#191 tape, with half the width of the tape covering the PVC blade and
the other half sticking to the fiberglass wing itself to smooth the
edge? I think it will hold on just fine, airspeeds will never exceed
about 150mph in this plane, and I think there is even a production
aircraft (one of the late-model composites) that attaches it's
plastic gap seal strips to the underside of the wing with double-sided
tape. Will it stay on? Losing it in flight probably won't pose any
problems at all, other than littering.

[Bob Kuykendall]

On Jun 19, 11:02 am, One's Too Many > wrote:
> A buddy of mine is contemplating making his flap gap seals from the
> thin PVC plastic blades salvaged from a set of vertical venitian
> blinds...

Been there, tried that. The vast majority of window blind slats have
too much curvature and are too stiff. That causes the seal to rub too
hard on the flap, causing to much control friction. It also causes the
seal to pry itself away from the double-sided mounting tape in short
order. Also, the foam mounting tapes are typically .040" or .060"
thick, which is way thicker than you want for good air flow.

Here's where to get the stuff that works:

http://www.wingsandwheels.com/page28.htm

or

http://store.williamssoaring.com/Merchant2/merchant.mvc

I typically use:

Tesa 4965 mounting tape

25mm pre-curved mylar

12mm PVC anti-peel tape

Sand both the wing (just where the mounting tape goes) and the
underside of the mylar with 220 grit. Apply the mounting tape, then
apply the mylar. Then use a ball bearing, skate wheel, or other roller
to press the mylar down onto the tape and the tape down onto the wing.
Then apply the anti-peel tape.

And, yeah, if you really got the bug you can make your own pre-curved
mylar, and you can substitute other stuff for the mounting tape and
anti-peel tape. Been there and done that too, and wasted no few hours
at it.

[One's Too Many]

Excellent!

Bob, you are a saint! That pre-curved mylar is exactly what we need.
I should've thought to go find out what the sailplane crowd was using.