Taping wingpanels

[Jurgen]

For F3J (and maybe same for f3B?) the tip panels are taped to the center panel. Is it nessessary to tape both topside AND underside, or is taping topside enuf? Refering to the forces in strong launchings. I know its little work to tape both but just wondering if i'm not doing an overkill doing so.
Jurgen.

[emersunn]

On a 2 piece wing I tape the top and wrap a little extra around the LE so it covers about 25% of the bottom. There is not a lot of force pulling your wings outwards.

I have never seen a tip on a 3 piece wing come off because lack of tape. I have only seen them come off when there is a spar or joiner failure.

I would be interested in others' opinion on this topic though . . .

[OVSS Boss]

I go ahead and seal the whole thing, a full size guy told me once that the wing seal on a full size at the root could add 25% to parasite drag of a ship, so I figure I need all the help i can get.

Marc

[T Tail]

You could forget the tape on the top, it's the tape on the bottom that gives it any strength. myself I tape top and bottom , only takes a few seconds more.

[screamin' eagle]

I would agree that added drag is a bigger factor than force pulling the wing panels apart. I once flew a pitcheron plane of mine on the slope and forgot to attach the wings together with the small retainer. They just slid onto the wing rod. Despite rolling the plane numerous times, at a high rate of speed, the wings didn't even begin to pull apart.

[LVsoaring]

As with just about anything, I'd have to say...It depends. First, if it's a slow gasbag, drag is not a big deal. On the other hand, if it's fast and slippery, top and bottom will probably help reduce some drag. Second, regardless of type of ship, there is roughly 10-15% of the bending force outboard where most outer panels attach as compared to the center of the wing (figures courtesy of Dr. Mark Drela), so strength is really not an issue. As Emersunn pointed out, a failure is gonna be due to the joiner letting go, not the tape failing. OVSS BOSS mentioned full size sailplanes, and he is correct, however that applies to the root. Full size machines rarely have removeable tips that comprise 25-30% or more of the span, plus they of course have a much higher wing loading. Bottom line.... tape is for holding the panels in place, not for structural strength. So, my advice it to experiment and do what works best for you. Just dont experiment with no tape at all! :eek:

Rick

[rogerflies]

It depends on the tape, too. Some, like the Scotch Magic tape I use, don't conform to compound surfaces very well, so taping the top of a panel intersection results in lots of creases and ridges, and increased drag.

I built a Cumic with the outer bay of the inner panel as part of the removable tip, so the Magic tape could go on smoothly all the way around the joint.

I think the best approach is to get the joints as smooth and tightly matched as you can. Then use tape on the part of the joint where it'll go down smoothly to hold the panel in place.

Roger

[Shortarse_Yoda]

The only time I have found the tape will tear is when spearing the nose in an f3j style 'positive' landing. Launch loads are not an issue.

Cheers SY

PS I've found insulation tape best, diamond tape tends to leave a residue after a view uses!