epp leading edge with bailing strap?

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sgilkey
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Post by sgilkey »

Roy, the strapping material won't do it for a spar, you'll still need some rods or other spar material. the strapping makes a great (cheap and light too) LE reinforcer that absorbs energy better than a f/g rod. in combo with an EPP LE it's really nice. I spray the 3M77 on the strapping to give "bite" and then glue on with PU glue, but just sticking it on with 77 and then wrapping with bidi is even simpler and probably just as tough (maybe even better!)
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boiler
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Post by boiler »

I've been using the strapping material for the trailing edge on my wings. It helps prevent the foam from ripping in a hard dirt nap which I seem to take far too often. I last used 3M 78 Styofoam adhesive on the foam and strapping material. Let it sit a few minutes then press together.
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Which_way_is_up
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Post by Which_way_is_up »

First of all it's good to see others starting to use EPP LEs on their wing offerings. At least in SSC, I think that it provides substantial energy absorption putting less stress on the rest of the wing structure. Since I use the full vertical basswood spar design that Lee brought out with the first Falcons I've found that the only problem with the EPP hasn't been in the area of the transition from the EPP to the blue foam but actually on the LE or the front of the EPP. Because of the nature of the EPP material it tears easily without additional support. And so we overlay a couple of overlapping layers of BIDI tape on the LE of the EPP. Giving it a good protective shell so that the EPP can still compress but not be torn by a serious LE to LE impact.

In the Smack II wings that I built I continued to use the full vertical spar and found that they actually absorb more of the impact energy then fiberglass rods and as a result ensure less damage to rest of the wing structure. The fiberglass rods let the wing flex but the structure of the wing still has to absorb the majority of the impact energy. For those that like the use of fiberglass rods, they would probably see improvements in the reduction of wing structure damage by using this strapping as an additional element of energy absorption.
Alex Treneff
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Post by Alex Treneff »

<blockquote id="quote"><font size="1" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by boiler</i>
<br />I've been using the strapping material for the trailing edge on my wings. It helps prevent the foam from ripping in a hard dirt nap which I seem to take far too often.<hr height="1" noshade id="quote"></font id="quote"></blockquote id="quote">

Bob,

Are you using the bailing stuff on your new wings covered completely in B-Di? I take dirt naps and don't seem to rip the TE (or much of anything) as long as the whole wing is in Bi-di.
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boiler
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Post by boiler »

Alex, I'm using bi-di on the trailing edge, spar, and leading edge but not everywhere. That stuff is heavy. The strapping material is extra stong and light insurance. I like to overbuild if it doesn't get too heavy. BTW, after losing one vertical stab and finding another severely loose, I've started using goop between the angles and the vertical stab. I may try a interlocking cut like the Pirahna used as well. It's worked great on my 2548 planes.
Ben Morrow
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Post by Ben Morrow »

Hey "Hat",
Thanks a ton for the leading edges, Man they fit perfect! And the cut is Right-On, very nice and smoooooth cutting!! SUPER FAST shipping too!!! Thanks Buddy, they look GREAT!!![8D]
Captain America
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Post by Captain America »

Ive been doing the samr thing Bob is talking about. Most of my breaks have been to the TE. Reall helps out.
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Ed Kettler
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Post by Ed Kettler »

Scott,

In addition to the strapping tape on the trailing edge, I'm trying a new approach on the Hawker Typhoon to keep the wing cracking lower. I ran some of the strapping tape from the T/E center point forward to mid-span. I'm hoping this will reduce the amount of split foam from the wing snapping forward in a dirt nap.

Of course, if I could figure out how not to dirt nap as often, I'd be in much better shape (and so would my planes)![:o)]

Ed
EK
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Post by EK »

Not all the TE cracks are the result of dirt naps. A hit on the wingtip also puts a big load on the TE. The LE tries to fold back and the TE ends up under compression. I just replaced a 6" square of starboard center section because of a wing tip hit in December. The wing didn't look that bad (the dent in the wing tip not withstanding) but the tape near the center was pulled (blown) up. The foam under the tape was like mush. No broken spars and aileron OK.
Captain America
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Post by Captain America »

Thats exactly what has been happening to me. Midairs split from the back of the spar to the TE. Im running narrow single di tape one wrap around the LE to TE in about 3 places. Should support it a little better. Im willing to give up an ounce or so if it means building/replacing less wings.
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