control surface repair

n9125a · Post by **n9125a** » Thu Apr 03, 2003 9:17 pm

Can anyone recommend someone to repair/straighten rudder & elevator. They're just a looking a little "collapsed". Thanks in advance........
Jim

Post by **GAHorn** » Thu Apr 03, 2003 9:29 pm

Collapsed? Like someone has been polishing them too aggressively and maybe overheated and "dished" them.

n9125a · Post by **n9125a** » Fri Apr 04, 2003 12:01 am

gahorn wrote:Collapsed? Like someone has been polishing them too aggressively and maybe overheated and "dished" them.

Exactly right. Any hopes of a fix?
Jim

N170BP · Post by **N170BP** » Fri Apr 04, 2003 5:08 am

A wheel barrow load of dry ice packed up next to the rudder
skins.....????

The answer/fix you probably don't want to hear, is to re-skin
them. Or find a decent replacement rudder (?)

Bela P. Havasreti
'54 C-170B N170BP

n9125a · Post by **n9125a** » Fri Apr 04, 2003 3:37 pm

N170BP wrote:A wheel barrow load of dry ice packed up next to the rudder
skins.....????

The answer/fix you probably don't want to hear, is to re-skin
them. Or find a decent replacement rudder (?)

Bela P. Havasreti
'54 C-170B N170BP

I've heard of the dry ice trick. I've also been told it has no effect. Can the skins be removed, gently straightened, and reinstalled? Or is the metal too fatigued to remain "straightened"?
Jim

N170BP · Post by **N170BP** » Fri Apr 04, 2003 4:01 pm

Never tried the dry ice thing myself.... but a friend
recently bought a '52 170 project that had hail damage.
The previous owner successfully removed most (if
not all) of the hail dings in the fuselage utilizing the
dry ice & dolly trick.

Having just completely rebuilt an early C-180 rudder,
I can suggest that if you are willing to drill the old
skins off, you might as well just replace them with new
skins. I spent enough time removing the corrosion from
the insides of the 180 rudder skins that it would have
made economic sense to just buy new skin stock, which
is available from more than one source (Jim Haydon - sp?
comes to mind).

Bela P. Havasreti
'54 C-170B N170BP

doug8082a · Post by **doug8082a** » Fri Apr 04, 2003 5:04 pm

Could someone (Bela?) enlighten us on the "dry ice trick"? I have some minor skin damage and have been considering reskinning the rudder.

zero.one.victor · Post by **zero.one.victor** » Fri Apr 04, 2003 5:25 pm

Per "Cessna Parts" category in T-A-P,
"Corrugated skin..........call Karl 360-757-1946" in Bow WA. Jim Hayton (in Sedro Wooley) priobably buys his skins there. Jim is more the guy to see for a complete airframe rebuild. He rebuilt Jan Liberty's 180 after a hangar at Harvey collapsed on it a few winters ago--it came out beautiful.
Bela,who bought the '52 project?

Eric

N170BP · Post by **N170BP** » Fri Apr 04, 2003 7:24 pm

Thanks for the contact on the skins (Karl in Bow).

I've never done it, but the way it was explained
to me, you need access to both sides of the skins
to do the dry ice trick. You rub the ice on one
side and gently push the dented skin back out
with the dolly on the other side (slide the dolly
back & forth a bit). There's no doubt a little "art
form" thing to it, and if you're trying to repair
an aircraft with hail damage, I bet a guy could
get pretty good at it after dozens of attempts!

A buddy of mine I work with bought the '52 project
(his name is Tim Shaver, he lives at Crest). This
'52 sat in a pole-building/barn in Kent and in a
garage in the Bonney Lake area for many years
in a partially restored state.

Bela P. Havasreti
'54 C-170B N170BP

Dave Clark · Post by **Dave Clark** » Sun Apr 06, 2003 1:26 pm

If there was a photo I couldn't see it to get an idea of the "dishing" that was mentioned. I have had considerable sucess on many planes in straightening a dishing by inserting a very long slender screwdriver and twisting or pushing the handle to force the tip against the skin along the "V" while pulling it back out. Take it a little at a time. A small phillips type is best or you could do some grinding and make a tip that more precisely fits the groove. You need a quality tool that is hardened along its length so it won't bend. This has worked on rudders, elevaters, flaps, and ailerons for me with much succes. Sure makes them look better.

n9125a · Post by **n9125a** » Mon Apr 07, 2003 12:19 am

Dave Clark wrote:If there was a photo I couldn't see it to get an idea of the "dishing" that was mentioned. I have had considerable sucess on many planes in straightening a dishing by inserting a very long slender screwdriver and twisting or pushing the handle to force the tip against the skin along the "V" while pulling it back out. Take it a little at a time. A small phillips type is best or you could do some grinding and make a tip that more precisely fits the groove. You need a quality tool that is hardened along its length so it won't bend. This has worked on rudders, elevaters, flaps, and ailerons for me with much succes. Sure makes them look better.

Sounds like good (and cheap) advice. I'm going to call it Plan "A". Thanks.....
Jim

wa4jr · Post by **wa4jr** » Tue Apr 08, 2003 3:58 pm

I don't know if I would try this on my plane or not, but I have seen folks spray the expanding foam sealer inside their control surfaces. When the sealer expands...IF you spray in the correct amount...the control surface is brought out true and you no longer have the hollow oil canning sound. Needless to say, if you mess up and get too much sealer in the cavity, you end up with some really funny looking "bulges" in your skins...but then maybe you can compress them down to proper appearance with your hands as the stuff expands. Has anyone here done this???

lowNslow · Post by **lowNslow** » Tue Apr 08, 2003 4:15 pm

Spraying foam into the control surfaces doesn't sound like a good idea. For several reasons 1) it would effect the control surface balance 2) the foam would trap moisture resulting in a corrosion problem and 3) the FAA would frown on this procedure.

Karl

Post by **GAHorn** » Wed Apr 09, 2003 4:44 pm

wa4jr wrote:I don't know if I would try this on my plane or not, but I have seen folks spray the expanding foam sealer inside their control surfaces. When the sealer expands...IF you spray in the correct amount...the control surface is brought out true and you no longer have the hollow oil canning sound. Needless to say, if you mess up and get too much sealer in the cavity, you end up with some really funny looking "bulges" in your skins...but then maybe you can compress them down to proper appearance with your hands as the stuff expands. Has anyone here done this???

No, No, NO!! Don't do it! The foam will not only attract water, hold it, and cause corrosion,...but it will also change the balance of the controls from day to day depending upon the moisture. It will also eventually break down into powder due to vibration, and then you'll have a real mess on your hands trying to correct this major error. (Anyone you've seen do this should be warned about this, and placed into the looney bin.)

Dave Clark · Post by **Dave Clark** » Thu Apr 10, 2003 12:57 pm

Try the screwdriver. The tool I mean, not the drink. OK you can do both but finish with the tool first. Seriously it works great. Take it easy at first until you get the hang of it. With the tool I mean. You can go all out with the drink