Piper fuselage adhesive

Timbeck2

Final Approach
Joined
Nov 4, 2015
Messages
9,161
Location
Vail, Arizona
Display Name

Display name:
Timbeck2
I just noticed that the skin on on panel on the right side of my Cherokee has come from together from the little stiffener inside. It isn't really a spar or a stringer as it just has one rivet at the top, one rivet at the bottom and the skin is glued on in the middle. Anyone know what kind of adhesive they used for this? Tech support is closed until Monday.

My mechanic seems to think that we need to remove it, clean off the adhesive, re-glue it and rivet it back together. I say that is overkill but he'll do whatever the tech guy says.
 
Try some of Sacs Coleslaw. It's "stick to your ribs" good or so he claims. Should work on a Piper.
 
Stiffeners are sometimes called intercostals on larger aircraft.

Your mechanic is probably correct. Can you see any squeeze-out of the previous adhesive and if so what color is it?
 
Contact the Grumman Gang. Somebody must have some of the Purple Passion glue way in the back of the hangar....
 
Is properly more of a sealant

My mechanic seems to think that we need to remove it,

Clean it up, check for underlying damage, reply sealant, rivet back in place, done.
 
Stiffeners are sometimes called intercostals on larger aircraft.

Your mechanic is probably correct. Can you see any squeeze-out of the previous adhesive and if so what color is it?

The previous adhesive (if that's what it is) is 47 year old yellow dust at this point. The intercostal or whatever it is called is just an L shaped piece of aluminum installed vertically behind the skin, it has two rivets, one on the top and one on the bottom. It's only purpose it would seem is to keep the outer skin from moving inward. The skin is riveted one foot away on both sides of this thing.
 
Obviously it's just to prevent oil canning which could be annoying and eventually crack. Good luck with you A&P, I know what I would have done.
 
The previous adhesive (if that's what it is) is 47 year old yellow dust at this point. The intercostal or whatever it is called is just an L shaped piece of aluminum installed vertically behind the skin, it has two rivets, one on the top and one on the bottom. It's only purpose it would seem is to keep the outer skin from moving inward. The skin is riveted one foot away on both sides of this thing.
Sounds like old Boeing cold bonding adhesive. Boeing would have you cut it in half, or remove it, clean off old adhesive, inspect for corrosion, prep, apply faying surface sealant such a PRC_ and install, adding some rivets that weren't previously there.
 
The A&P should know the proper repair, Piper has a very good structural repair manual. the answer is in there.
 
When I said: "My mechanic seems to think that we need to remove it, clean off the adhesive, re-glue it and rivet it back together." I meant that he wants to rivet the entire length, not just the one rivet on each end as it is now. I think that is overkill. I'll call tech support on Monday to see what they want me to do.
 
When I said: "My mechanic seems to think that we need to remove it, clean off the adhesive, re-glue it and rivet it back together." I meant that he wants to rivet the entire length, not just the one rivet on each end as it is now. I think that is overkill. I'll call tech support on Monday to see what they want me to do.
They will most likely tell you to look in the structural manual. If the mechanic does not have one he should not be doing the repair.
 
When I said: "My mechanic seems to think that we need to remove it, clean off the adhesive, re-glue it and rivet it back together." I meant that he wants to rivet the entire length...
That is exactly what Boeing would have you do, including faying surface sealant along the full length.
 
Last edited:
That is exactly what Boeing would have you do, including faying surface sealant along the full length.
And since it's not a Boeing that has no bearing on the discussion. Tom is right, the proper repair is what's called out in pipers approved manual.

Bob
 
Which I don't have and have to call someone who does to find out what needs to be done.
 
Well I called Piper (what a chore to find the right number for a tech rep but finally...) and sent the pictures to the tech guy. Waiting on word but initially he seems to think that I would probably be getting the part number to the adhesive and re-bonding it. I guess we'll see.
 
Sounds like something assembled with EA9309.3NA adhesive to me. It's sold in 50 gram packs and much larger quantities.
 
Obviously it's just to prevent oil canning which could be annoying and eventually crack. Good luck with you A&P, I know what I would have done.
Sense when did you become the piper expert?
 
And since it's not a Boeing that has no bearing on the discussion. Tom is right, the proper repair is what's called out in pipers approved manual.

Bob
and many times Piper and others, leave the minor repairs to the A&Ps judgement.

after all they are licensed mechanics that were taught in A&P school how to repair aircraft. unlike glen who must have a book to tell him how to do anything.
 
and many times Piper and others, leave the minor repairs to the A&Ps judgement.

after all they are licensed mechanics that were taught in A&P school how to repair aircraft. unlike glen who must have a book to tell him how to do anything.
if the manual does not address it, I agree, accepted practice is acceptable. in this case, clean it up, a bead of proseal and a couple of new rivets, good to go. the OP's A&P's idea of adding rivets that the design does not call for is NOT acceptable in my option. without a load analysis, making a part "stronger" changes the load paths and may make something else weaker.

bob
 
if the manual does not address it, I agree, accepted practice is acceptable. in this case, clean it up, a bead of proseal and a couple of new rivets, good to go. the OP's A&P's idea of adding rivets that the design does not call for is NOT acceptable in my option. without a load analysis, making a part "stronger" changes the load paths and may make something else weaker.

bob
What you say is true, BUT, if this is a known problem, there may be a AD or service bulletin on it. When you talked to the tech support at Piper if they didn't mention it, there probably isn't any.
 
and many times Piper and others, leave the minor repairs to the A&Ps judgement.

after all they are licensed mechanics that were taught in A&P school how to repair aircraft. unlike glen who must have a book to tell him how to do anything.
No personal attack there....
Sense when did you become the piper expert?
It's "Since", Tom.
 
Okay the plot thickens. The tech rep sent me a picture of the drawing and the stiffener (that's what I'm calling it because I don't know) isn't even depicted. He wanted to know if it was added later. There is no record of it. Waiting on words again.

This airplane ownership thing.... (insert smiley faced dude blowing his brains out)
 
Okay the plot thickens. The tech rep sent me a picture of the drawing and the stiffener (that's what I'm calling it because I don't know) isn't even depicted. He wanted to know if it was added later. There is no record of it. Waiting on words again.

This airplane ownership thing.... (insert smiley faced dude blowing his brains out)
Awesome. Minor alteration?
 
:dunno:

With my luck, nothing is minor. However, my problems with my Cherokee don't hold a candle to what my buddy Phoenix is going through.
 
By the way. I've got pictures on my phone if anyone wants to post them send me a pm with your info. I'm interested if other Cherokee 140 owners have the same stiffener I'm talking about installed on their plane. Mine is a '69 model although the finance company says its a '70.
 
Since airplanes are airplanes. You want to wager who could transition quicker, you to MD-10s, or I to Pipers?
Problem is, you haven't. while I've been out here doing pipers and Cessna's you've ben hiding out in some big factory reading your little job cards.
 
You don't have any clue as to what I do.
I'm close enough with your statement about inspecting struts prior to Christmas. You sure as hell ain't out here in the weather doing annuals.
 
And you ain't out here in the winter doing what I do outside. I work at an airline maintenance base that's also a hub. I go to the line all the time.
 
And you ain't out here in the winter doing what I do outside. I work at an airline maintenance base that's also a hub. I go to the line all the time.
Well good for you, but I bet there isn't a piper there.
With your knowledge of part 91 ops I hardly believe you are an A&P let alone a IA.
 
Back
Top