What's new
Van's Air Force

Don't miss anything! Register now for full access to the definitive RV support community.

Wing walk doubler skins

uk_figs

Well Known Member
Friend
Just started to install the wing skins and the instructions refer to making the doublers from a AS3-025x9 3/8x26 alum sheet, I do not have such a sheet in the wing kit or listed on the kit list. I do have two AS3-025x10x48 sheets, is this what I am supposed to use and cut down to size (have not found where this is used elsewhere)
Thanks
Dave
 
just to add, I didn't bother trimming it width-wise.. 10" is just fine... just cut it to length (26") and you're good to go.
 
Oh, by the way, I believe the instructions are wrong on the wing walk doublers where it says they overhang the rear spar "by about an inch." It actually only overhangs the rear spar (the aft edge of the flange) by about 5/32"
 
Bob, YAH! I loved that part!

About an inch! I scratched my head for hours wondering how I could be measuring it wrong!

About an inch... I will give you an inch!

:rolleyes: CJ
 
wing walk doublers

I measured the 1 inch from the plans, how do you know how much the overhang needs to be if it is not the 1 inch stated.
 
wing doubler

I did not cut the sheet to length first, I mounted the sheet under the wing skin on the rib frame against the fwd spar and then measured 1 inch overhang from the rear of the rear spar and marked and cut at that point.
Did I do this incorrectly?? Is the balance of the sheet used later somewhere else (and now will be too short) :rolleyes:
 
I can't recall what the plans say, but I will say that one of the first things I learned -- the hard way -- is to cut dimensions to what the plans say and ignore what the narrative says.

You're going to have to cut back the doubler until it is just slightly (as indicated above) overhanging the rear spar. If you don't, I believe the doubler will hang up the flap.
 
I cut this part per the plans, and it does not interfere with the flaps at all. I did this nearly a year ago, so I cannot remember exactly how far it extended past the rear spar, but I know it was something like 3/4"-1". It did not extend all the way to the edge of the top skins, though. There's really nothing here to interfere with the flaps, which are radiused on the front, and do not touch the top skins except at the very back edge.
 
Yeah, I don't remember what the deal was, I do remember posting on the old YahooGroups site when I was at this stage, and folks said there was concern about overlap with the flap.

The bottom line is this: just the follow the plans. They almost never lie.
 
Prime the doubler?

I am working on the doubler now. Wondering if people are priming it? With two layers of aluminum. it seems to me that any moisture between the layers would be a set up for corrosion. Thoughts?
MLWynn
RV 8 Wings
San Ramon, CA
 
I primed mine! Doesn't hurt.

It makes a durable layer betwen the substrate and the environment. This will mitigate corrosion.

Do it!

:D CJ
 
Wing walk doubler

I had the same question concerning the 1" overhang. Per Van's, (last year at OSH) use the 10 x 26" dimension with the 5/32 overhang. When they say it overhangs the rear spar by 1", I think they mean that it extends beyond the forward edge of the rear spar by 1" (hindsight). Apparently, if left at a 1" overhang, it can interfere with the flaps. I have one at 1" OH & one at 5/32" :rolleyes:
 
Doubler Overhang

I have the 1" overhang on my 6A WW doubler.

One day (after about 50 hours of flying) the flaps (electric) bound-up and released with a bang during retraction.

My guess is the pilot (me) stepped on the wing skin aft of the rear spar and bent the doubler down. The doubler caught on the rolled leading edge of the flap during retraction and folded the doubler forward over 120 degrees. This probably wouldn't have happened with manual flaps, but with electric flaps, and the big fan up front running, I didn't notice the additional effort required to retract the flaps

The only solution I could come up with was to cut the damaged doubler off about 1/8" aft of the rear spar with a dremmel cut-off tool and clean-up the new aft edge.

I'm not the first to have this problem. Since the doubler isn't riveted to the top skin aft of the rear spar the 1" overhang is a problem waiting to happen.

I have a couple ideas to prevent the dreaded 1" overhang flap-snag if your wing is already finished.

1). CUT IT OFF! Using a 1" dremmel cut-off disk. Slide a very thin piece of stainless between the two pieces and carefully cut that sucker off before it causes you problems.

2). Carefully spread them open a little, scotchbrite and solvent clean, then apply a very thin layer of tank sealant and clamp them together until the sealant cures. Use care and make sure you don't distort the top skin and mess-up the airfoil. This is just and idea and I haven't tried it, so you are experimenting with this one!

Good luck,
 
I love this site! Almost every question I come up with already has an answer. This thread was worded almost the same as what I had typed when I thought "better search". :eek:

Thanks to everyone who shares info here it is a great resource. :D

This was just what I needed!
 
JohnR said:
I love this site! Almost every question I come up with already has an answer.
I feel the same way John. I will go one step further and say this site even has answers to questions I didn't know I had. :D
 
RV7Factory said:
I feel the same way John. I will go one step further and say this site even has answers to questions I didn't know I had. :D

You got that right.
After seeing what this thread was about just now, I figured I should take another look at my QB wings just to see what they did in the Phillipines.

Using my handy precision ruler, I noted that the doubler on both of my wings extends out just 3/32" so I guess someone at the QB factory got it right a long time ago.
 
I am now at the doubler phase and am glad I took 5 minutes to read this post. Thank you

-Ron
 
After searching for the Wing Walk Doubler stock that is not in the kit for a few minutes, I remebered seeing something on this here. Sure enough, its all right here :D

Nice!
 
refreshing this post as it's been quite a few years. In my RV-8 wing kit, there is neither the AS-025x9 3/8x26 sheets, or the AS-025x10x48. I verified this on the packing slip. I guess Van's assumes you will have this spare from the fuselage kit??

It's too bad Van's doesn't recommend some of these extra parts as additions when ordering the wing kit first.
 
Last edited:
Back
Top