Aluminum Aileron questions

[Nick]

Howdy folks,

The aluminum aileron skin in the plans has a rounded ridge pressed into it every couple of inches. I've noticed that the ridges on most aircraft ailerons (ie C172) are V-shaped. Was wondering if anyone had an opinion on the round vs vee shaped aileron ridges.

Also, does the aluminum need to be painted before it is rivetted? Or are unpainted areas inside joints OK? What sort of preparation is common for aluminum before painting?

Aluminum is all new to me so any of your experience is appreciated.

Thanks in advance

Nick

[splischke]

Nick,

I don't think it makes any difference whether the ridges are v-shaped or round but I believe most Classic builders opt for round. The source for the skins (with round ridges) is listed as Tom Flock on my plans but the tooling, last I heard, is in the hands of Tom Brown of Unity Wisconsin. I purchased my skins from Mr. Brown a few years ago for $50 per skin. Mr. Brown's phone number is (or was) 1-715-223-4444.

I built a Sonerai which has an all aluminum wing. I primed all parts separately before assembly for best corrosion protection. I'll do the same for my Classic's ailerons.

-Scott

[splischke]

I forgot to mention that if you decide to make your own corrugated skins, there's an excellent how-to article on the subject in the February 1986 issue of Sport Aviation. EAA members can log into the members only area of www.eaa.org and download the article for free. Once you log in, use the link below to go directly to the article.

http://www.oshkosh365.org/saarchive/eaa ... _02_22.pdf

-Scott

[mmcgrew]

You do not need to buy the skins. I made mine with a press I made from a Hyd jack and some 2 X 4". Some one on this site has the original plans. probably in the archives. Really simple top make.

Michael N838MM

[Nick]

Hello Gents and thanks for the remarks.

I do absolutely plan to make my own aileron skins with my own press based on the Feb '86 article. That's the fun bit! I'm curious as to why most classic builders would opt for the rounded ridges. Is that common in "authentic" old aircraft?

On to another question. The plans have a hardwood strip between the top and bottom skins up until the aileron curves toward the tip, at which point the wood is discontinued and the skins are riveted together with an aluminum strip between. But since there is no longer a gap between the skins (there's a 1/8" gap made by the hardwood) the skins will have to squeeze together to fill the gap. It seems there'd be a triangular gap left in the trailing edge just outboard of the hardwood strip. The trailing edge would be thicker where the wood is, than where it isn't. I hope that description makes sense. Does anyone have any photos of the the trailing edge of their aluminum ailerons to see how it turned out?

Thanks

Nick

[mmcgrew]

I ran my ailerons out to the wing tip. I did not like the thin edge look at the wing bow. So I used a narrow and thin (.090) aluminum spacer between the skins and when I got to the end I formed a wider spacer that matched the wing bow shape and ran this to the hinge. A lot of work - but a great look at the wing bow.

Michael
N838MM

[Nick]

Hey folks,

My 2024 aluminum for my ailerons is on the way. But yesterday I had an A&P tell me that 2024 doesn't like sharp bends or slow working, only a really fast press, otherwise it over-hardens. He was concerned that my plan to press my own aileron corrugations might leave me with over-worked aluminum. Too hard and brittle.

Has anyone ever experienced any problems pressing their own corrugations into 2024 aluminum? Or did you use a different alloy?

Thanks guys.

Nick

[Nick]

Echo...echo....echo....echo.........

Phhht Phhhhht, is this thing on?



Any metallurgy experts out there?

[dougm]

Yes, it's on

Sorry Nick, I can't answer your question, but hopefully someone else here can.

[Bill Rusk]

Nick

You are a funny guy. I am not much of a sheet metal guy but 2024 does not like to be worked. I would consider a softer alloy, 3003 perhaps. I do know a guy that can help. I'll try to call him tomorrow to get more info.

Bill