First look at the aileron

[mhorowit]

I took the fabric off the left aileron this afternoon. I see some white power (pic) on the metal (which I assume is corrosion), but don’t notice any pitting. The steel tube at the distal end is rusted thru (pic), but I can bend a new piece easily; it appears to have an interesting fitting where it connects to a wood end piece. At the trailing edge, the steel tube connects to an aluminum strip; I thought one didn’t do that with dissimilar metals; guess I’m wrong.

I was concerned about the possibility of a split spar (pic), but recalled that we’d discussed that in many cases we could expect to see the spar made of two pieces glued edge-to-edge.

The aluminum ribs all look good and the aluminum inside the ribs still looks shiny; I’m tempted to ask if I really need to take this apart, or can I treat it without removing all the screws and nails. Any opinions? - Mike

[Winston L.]

Re: First look at the aileron

I would replace the steel tip bow as you said. The corrosion on the aluminum that I see in the picture could be cleaned when it is assembled. Look for any corrosion inside the leading edge on the aluminum. Check between the ribs and the leading edge as well as you can see. If all of that looks good you could prep and cover again from what I see. It is important to identify and stop any corrosion though. Any place you remove corrosion on the aluminum I would prime at least with zinc chromate. If you are covering with stits I would use the epoxy primer they call out for (on areas that will come in contact with the fabric). Look at the spars closely and make sure you don't see any discoloration or rot.


Winston

[crispy critter]

Re: First look at the aileron

I took the fabric off the left aileron this afternoon. I see some white power (pic) on the metal (which I assume is corrosion), but don’t notice any pitting. The steel tube at the distal end is rusted thru (pic), but I can bend a new piece easily; it appears to have an interesting fitting where it connects to a wood end piece. At the trailing edge, the steel tube connects to an aluminum strip; I thought one didn’t do that with dissimilar metals; guess I’m wrong.

I was concerned about the possibility of a split spar (pic), but recalled that we’d discussed that in many cases we could expect to see the spar made of two pieces glued edge-to-edge.

The aluminum ribs all look good and the aluminum inside the ribs still looks shiny; I’m tempted to ask if I really need to take this apart, or can I treat it without removing all the screws and nails. Any opinions? - Mike

Mike,
I might have an aileron tip bow and maybe even a good leading edge.I have several aileron parts and I think I even have a few servicable ailerons. You can have what you need if you want to pay shipping.

[Ragwing nut]

Re: First look at the aileron

Make sure the doubler plates are still attached well. I have taken alot of them apart and found although the spar was still good, the glue joint has failed around doubler. If those are still good, repair revarnish, and go on.

Mike

[mhorowit]

Re: First look at the aileron

Mike,
I might have an aileron tip bow and maybe even a good leading edge.I have several aileron parts and I think I even have a few servicable ailerons. You can have what you need if you want to pay shipping.

That's very generous Kevin - thanks.
Before I can take advantage of your offer, I need to evaluate where I stand with this part.
I know next to nothing about how to work with AL except that using steel wool to remove the white powder is probably not a good idea (embedding steel fibers in soft AL (jump in if I'm wrong).
I'll take a better look at it tomorrow. - Mike

[mhorowit]

Re: First look at the aileron

Make sure the doubler plates are still attached well. I have taken alot of them apart and found although the spar was still good, the glue joint has failed around doubler. If those are still good, repair revarnish, and go on.

Mike

Got something going on this weekend, but I'll remove the various brackets ASAP and give the doublers (at first glance the appear to be three) a good look. - Mike

[crispy critter]

Re: First look at the aileron

Mike,
If you want to use steel wool or wire brushes on of the aluminum you can do so "BUT" make sure you only use brass or stainless steel.

[mhorowit]

Re: First look at the aileron

At the trailing edge, the steel tube connects to an aluminum strip; I thought one didn’t do that with dissimilar metals; guess I’m wrong. - Mike

Ah - on drawing D-A803 we see the note "Use zinc chromate primer prior to assy of any steel parats that come in contact with Aluminum spars"; that's a good answer - Mike

[cpirrmann]

Re: First look at the aileron

That's very generous Kevin - thanks.
Before I can take advantage of your offer, I need to evaluate where I stand with this part.
I know next to nothing about how to work with AL except that using steel wool to remove the white powder is probably not a good idea (embedding steel fibers in soft AL (jump in if I'm wrong).
I'll take a better look at it tomorrow. - Mike

We used scotchbrite pads to clean the aluminum in the Navy.
Then treated with alodine before we primed and painted.
That was 25 years ago though.

[mhorowit]

Re: First look at the aileron

... steel parats ...

Yes; you've heard of the "Iron Butterfly"?, this is "Steel Parrots" a garage band out of Biloxi.

[mhorowit]

Re: First look at the aileron

We used scotchbrite pads to clean the aluminum in the Navy.
Then treated with alodine before we primed and painted.
That was 25 years ago though.

Scotchbrite is what my A&P uses on steel tubing; I'll give it a try since it's not metalic therefore little risk. Thanks - Mike

[mhorowit]

Re: First look at the aileron

Mike,
If you want to use steel wool or wire brushes on of the aluminum you can do so "BUT" make sure you only use brass or stainless steel.

Kevin - maybe I'm reading wrong, but you seem to be saying two things I'd ask for clarification on:

1. Do they make Brass or Stainless "steel wool" pads? My wife uses a stainless scrubbing 'bud' for pots and pans; is that what you are talking about?
2. Are you saying I can use a brass or stainless steel brushes? Are scratches a concern? - Mike

[crispy critter]

Re: First look at the aileron

Mike,the stainless steel or brass brushes work great for cleaning heavy paint and/or corriosion just don't use them where you can do the job with something less abrasive.

[N96337]

Re: First look at the aileron

That doesn't look too bad in there, Mike. My aileron spars were all crushed at the bolt holes when I opened mine up. Personally, I wouldn't be able to stand it if I didn't pull the bolts and nails and at least move ribs over so that I could get a really good dose of PolyFiber's Epoxy Varnish all over that spar!! But, that's just me.. you'd most likely be ok to just coat what you can see, but if you pull stuff off, there's no doubt about what's under there and the glue joints for the doublers, plus you can get varnish down inside the bolt holes to help seal the wood there too.
You're on the right track with the tip bow, and if it was me, I'd be epoxy priming both sides of everything metal that would come off...plus installing all new hardware.
JH

[mhorowit]

Re: First look at the aileron

... and if it was me, I'd be epoxy priming both sides of everything metal that would come off...plus installing all new hardware.
JH

All the bolts will be replaced; I'd like not to have to think about removing those hex headed sheet metal screws(?) that are about 1/8" across the flats. - Mike