First look at the aileron

[mhorowit]

Re: Is this masking tape?

Thanks for the tape info.
I'll clean up one of the screw heads and take a pic later today - Mike

Rob - here you go; 5/32" across the flats - Mike

[mhorowit]

Re: Is this masking tape?

Mike: Please don't use masking tape...it's paper-based and will retain moisture. All my screws had this stuff (probably from original manufacture) and these days it's poor practice. Also, the next person recovering in 30 years time, he'll be cursing your name forever.

I don't know about other than the Poly-Fibre process, but they use a cloth self-adhesive tape...I'm sure the other systems use similar. Don't use it in long strips...just in short patches; it won't show under the fabric too much, and in long strips, the long edges will curl up.

Think of banknotes...they are cotton-based (despite it being called "paper" money), and will survive going through the washing machine.

By the way, what Hex-head screws were you referring to earlier?

Rob

Thanks for the tape info.
I'll clean up one of the screw heads and take a pic later today - Mike

[Robert Lees]

Re: Is this masking tape?

Mike: Please don't use masking tape...it's paper-based and will retain moisture. All my screws had this stuff (probably from original manufacture) and these days it's poor practice. Also, the next person recovering in 30 years time, he'll be cursing your name forever.

I don't know about other than the Poly-Fibre process, but they use a cloth self-adhesive tape...I'm sure the other systems use similar. Don't use it in long strips...just in short patches; it won't show under the fabric too much, and in long strips, the long edges will curl up.

Think of banknotes...they are cotton-based (despite it being called "paper" money), and will survive going through the washing machine.

By the way, what Hex-head screws were you referring to earlier?


Rob

[mhorowit]

Is this masking tape?

Over isolated screw heads and along rows of screws is what appears to be a strip of masking tape; obviously providing a smoother surface for the fabric.

Is it simply masking tape or something less likely to retain moisture? - Mike

[Robert Lees]

Re: First look at the aileron

I'm coming into this discussion a bit late....

spar made of two pieces

Mine were in three laminations, Mike...although one had indeed split along a glue line:
I ended up replacing both spars. Have a good look.

dissimilar metals

That's what pigeon poo is for!

Look for any corrosion inside the leading edge on the aluminum

That's very difficult to do, Mike, without de-nailing the leading edge. Try with a fine torch (oops..flashlight) through the nose rib lightening holes.

If you are covering with stits I would use the epoxy primer

Also, the "new" Superseam is the same as the Stits product (MEK-based PolyTak), so the same precautions will apply. "Old" and "new" Superseam are not chemically compatible.





With reference to "Alodyning": that is the trademarked name of a particular chemical process (perhaps DuPont?). Stits has their own version called "Aluma-Dyne E-2300"...fundamentally both are a chemical process whereby the surface atoms are converted to a ceramic-like material which is very impervious to corrosion-promoting agents like oxygen. Alodyning is a two-part chemical mix; the Stits equivalent is single-part.

Unfortunately, this coating is thin and brittle, so is easily damaged by handling etc...my own suggestion is to either alodyne and then epoxy-prime, or etch-prime and then epoxy-prime.
Or better, do all three (which is what I did on all my aluminium).

Further, Anodising is an electro-chemical process. I don't know more...I'm not a chemist.

But be aware: all the above processes require an aluminium surface to work on, so all corrosion, dirt, grease, fingerprints, magic markers, lipstick etc needs to be removed before application. I used the Stits (sorry...Poly-Fiber) "Aluma-Dyne E-2310" acid-etch cleaner to perform this, using Mike's "stainless kitchen pads" and Scotchbrite (yet another tradename).

I won't go into the details of what I did to prevent future spar crushing at the bolt holes, because you probably can't do in the USA what I did here...all that info is available on my website.

As an aside, and only just off-topic, Winston's input to this group is very welcome; he seems to bring a wealth of knowledge which I'm sure is appreciated by everyone.

Rob

[alwaysoar]

Re: First look at the aileron

Mike--I took both my ailerons completely apart and replaced the spars, a couple of ribs, etc., scrubbed the leading edges, welded new ends on the tip bows. I epoxied everything. It was a big job. IF you end up doing that, number each rib and its location on spars. If you do that then the old screw holes in the leading edges will line up saving a lot of aggravation drilling new ones and hoping you can hit the rib on the other side.

Ed

[Winston L.]

Re: First look at the aileron

The original metal on the aileron was bare alclad. There are several manufacturers like Mooney that are alodining only.

Winston L.

[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.

GOOGLING for 'alodine' I found an interesting article
here.

But it begs a question. It talks about the alodine process followed by priming and then painting. But the leading edge of my aileron seems to be unprimed and unpainted aluminum. Does this mean the aluminum was originally anodized and didn't need further treatment, but we're alodining which requires at least a priming coat?:clue?:: - Mike

[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

[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

[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.

[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

[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

... steel parats ...

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

[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.