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  #1  
Old 11-29-2022, 05:15 PM
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claycookiemonster claycookiemonster is offline
 
Join Date: Oct 2007
Location: Midway, UT
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Default Is it worth it to try to "expand" wingtips?

Both wingtips are aligned and sized correctly. However, whether due to original molding or storage, one of them is "fuller" while the other is "thinner." One is generally and pleasingly Rubenesque, while the other one looks emaciated.

As far as I can tell, this is totally a cosmetic concern. I could put in a foam "rib" to plump up the thin one, but I'm wondering if in a year or so, after spending time in the sun, they would have equalized anyway? Maybe the relatively invisible "rib" will begin to show and then I'll have an odd ridge in the wingtip?

Is this worth attending to, or should I just learn to not see it?
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  #2  
Old 11-29-2022, 05:26 PM
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bjdecker bjdecker is offline
 
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Location: Georgetown, TX
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Default

Quote:
Originally Posted by claycookiemonster View Post
...Rubenesque...
ROFLMAO

Somewhere on here is a thread or 10 that describe in painstaking detail how to add a little more shape to them, and how to stiffen them up under flight loads.

They have a tendency to "pucker" or warp along the top *if* there is the slightest preloading after installation.

Careful not to make them into a Botticelli :O
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  #3  
Old 11-29-2022, 05:49 PM
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RV8JD RV8JD is offline
 
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Default

Not exactly what you're asking but something to consider ... My RV-8 has the WD-715-1 wing tips and the aft third deforms slightly in-flight as shown in the pic below. The tip of the TE bends upward a smidge and the upper skin buckles downward slightly due to air loads. The overall effect is a 'squeezing' of the aft third of the wing tip. The whole wingtip is very flexible. I try not to push down anywhere on the tip skins, as they flex easily, even when just wiping them down. After 1280 hours there is no cracking in the paint or the glass.

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Last edited by RV8JD : 11-29-2022 at 06:10 PM.
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  #4  
Old 11-29-2022, 07:49 PM
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wirejock wirejock is online now
 
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Default Sfiffeners

Pretty common to add stiffeners top and bottom fore/aft.
All sorts of methods. I used dowels. Epoxy them by holding them in place with a few strips of waxed lashing string. Remove the strings and layup a layer or two of fiberglass.
If I did it again, I would use fiberglass rod. The stuff the sell at the hardware store with reflectors at the top.
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  #5  
Old 11-30-2022, 05:41 AM
Desert Rat Desert Rat is offline
 
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Location: Wichita KS
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Default

Clay- When I bought my wings, they had been in storage for about 10 years. The wingtips had been sitting open side down and had pooched out horribly and worse, asymmetrically.

I took the worst of it out with a heat gun and then once they were match drilled to the tips, they sat for about a year on the wings in the wing stand. The Winter/Summer heat cycle seems to have equalized them somewhat.

I figure I'll fly them this way and revisit before paint to see if there's enough deviation that I want to put stiffeners in.
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  #6  
Old 11-30-2022, 05:57 AM
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I think itís worth the effort to make them look good and be a bit stiffer. I got a few hairline cracks in my paint job from stray hands on the wing tips before I got them stiffened up with a layer of fiberglass. Seems like they should be made a bit more robust.
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  #7  
Old 11-30-2022, 06:07 AM
KayS KayS is online now
 
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Location: lake constance
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Clay, if you haven't done first flight yet i would try to shape them equally using internal ribs etc. i wouldn't mind for cosmetics but these wing tips could have an significant impact on aerodynamics, especially as they are located most outboard with the longest lever arm. just to avoid painful head scratching later about the causes of the heavy wing etc.

and take care about the trailing edges of the tips... they should be straight and at the same level with the ailerons.
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  #8  
Old 11-30-2022, 09:51 AM
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BillL BillL is offline
 
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Location: Central IL
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Default Great question!

I would suppose you could just install a blocking plate, inflate them and sit in the sun, but you really don't know what it will look like after . . .

I slit the TE of my tips as they were quite misshapen. They were the very old white gelcoat (2002 era). Once the TE termination line was pleasing with the TE of the elevators, the thickness (of mine) was as much as 1/2". I slit the TE and sanded to create an even thickness as the cause was some very thick gelcoat in that area to glue the halves together. After separation and thinning, the pucker was greatly reduced. The ends had been pinched together and the gelcoat glue was reshaping that area.

The gray tips I have seen do not exhibit this characteristic and are lighter.
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  #9  
Old 11-30-2022, 11:18 AM
PhatRV PhatRV is offline
 
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I had a warp spot in one of my wing tips after it sat on the hot rafter for 4 years. I fashioned a curve rib from scrap aluminum and Cleco it to the warp area. Use heat gun and generally left the rib attached for a few months. The warp went away. Removed the false rib and filled in the cleco holes with micro
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