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-   -   structural adhesives instead of rivets (https://vansairforce.net/community/showthread.php?t=183724)

1bigdog 06-17-2020 02:48 PM

structural adhesives instead of rivets
 
I've done a terrible thing to one of the fuse skins. After I flatten it best I can the plan is to back it with a doubler.
Is it permissible to use a structural adhesive such as Loctite's EA 9017 or proseal in place of rivets. The dented area doesn't go through but it's dented/stretched enough I don't want to just ignore it, so that's why the doubler.
There is no useful mention of structural adhesives for 2024-T3 in AC43.13 so if anyone has other resources I could look at please let me know.
It's in a highly visible area on what will be a polished surface so I'm hoping to avoid the rivets.

Thanks for the guidance.

David Paule 06-17-2020 03:08 PM

The short answer is, absolutely not.

And that's from an engineer who is both gluing and riveting his fuselage together. While I don't know the EA 9017, the Pro Seal is clearly not a structural glue. To properly make a structural joint takes considerable prep, the right glue, and even then, how do you know what you have? Unless you do a whole series of joint-specific tests, and compare the strengths achieved to rivets, you're just fooling yourself.

Even on my plane, the parts that are glued, are also riveted. The glue is not only not needed, it makes repairs much harder.

Don't even consider it.

Dave

Scott Hersha 06-17-2020 03:15 PM

So the dented area you are trying to fix is skin damage between any underlying structure? If you are considering repairing damage that involves skin attachment to a rib, or any other structural member, I would say that adhesives in place of rivets is probably not a good idea, even though that is done that way as primary structure on some production airplanes - Grumman Americans, and Cessna jets come to mind. Our RV?s were not designed that way. If you are trying to fix an area of unsupported skin, then maybe it would be OK. But remember, this is a stressed skin structure where the skin carries part of the load. Your repair needs to be at least as strong as the original undamaged skin. Patching an area like this is usually done with a riveted doubler, as you mentioned, returning that part of the structure to it?s original, or better, strength. I understand your desire to end up with a polished airplane, and not wanting to see a patch. I think you should phone home (Vans) and get their take on it.

snopercod 06-17-2020 03:34 PM

I have never had any luck getting structural adhesive to bond with aluminum. I would never trust it.

Carl Froehlich 06-17-2020 03:44 PM

Just call Van?s and order a new skin. In the long run it is cheap, and you will not be looking at that area every time you get in the plane.

Carl

1bigdog 06-17-2020 04:40 PM

Not structure associated
 
Quote:

Originally Posted by Scott Hersha (Post 1440078)
So the dented area you are trying to fix is skin damage between any underlying structure? If you are considering repairing damage that involves skin attachment to a rib, or any other structural member, I would say that adhesives in place of rivets is probably not a good idea, even though that is done that way as primary structure on some production airplanes - Grumman Americans, and Cessna jets come to mind. Our RV?s were not designed that way. If you are trying to fix an area of unsupported skin, then maybe it would be OK. But remember, this is a stressed skin structure where the skin carries part of the load. Your repair needs to be at least as strong as the original undamaged skin. Patching an area like this is usually done with a riveted doubler, as you mentioned, returning that part of the structure to it?s original, or better, strength. I understand your desire to end up with a polished airplane, and not wanting to see a patch. I think you should phone home (Vans) and get their take on it.

There is no structure associated. It's just the skin that I want to reenforce but it is adjacent to the rib aft of the static hole on the fuse skin of an RV-9A. The rib was not affected. So to answer another question, no, ordering a new skin is not an option as the entire aft bottom skin would have to come off.

Hope that clarifies. And thanks for the responses thus far.

wirejock 06-17-2020 04:51 PM

Repair
 
Quote:

Originally Posted by 1bigdog (Post 1440093)
There is no structure associated. It's just the skin that I want to reenforce but it is adjacent to the rib aft of the static hole on the fuse skin of an RV-9A. The rib was not affected. So to answer another question, no, ordering a new skin is not an option as the entire aft bottom skin would have to come off.

Hope that clarifies. And thanks for the responses thus far.

A photo or two would help. If there is no underlying structure, there may not be a need to do anything. A dent in a skin can be filled. A bigger problem might be fixed with a doubler. Post a photo plz.

1bigdog 06-17-2020 05:21 PM

No photo op
 
Quote:

Originally Posted by wirejock (Post 1440094)
A photo or two would help. If there is no underlying structure, there may not be a need to do anything. A dent in a skin can be filled. A bigger problem might be fixed with a doubler. Post a photo plz.

Hi Larry

Sorry about this but I'm not on any social media and don't have access to any photo hosting sites so it appears I cannot post images.

But at least I'm getting an idea where the (now to be considered essential) Canadian flag decal will be going.

Cheers.

wirejock 06-17-2020 05:45 PM

Photo
 
Quote:

Originally Posted by 1bigdog (Post 1440102)
Hi Larry

Sorry about this but I'm not on any social media and don't have access to any photo hosting sites so it appears I cannot post images.

But at least I'm getting an idea where the (now to be considered essential) Canadian flag decal will be going.

Cheers.

Feel free to e-mail a photo. I will load to Imgur and post for you. E-mail is in my signature below

1bigdog 06-17-2020 07:19 PM

the photo's
 
Hi Larry

Very kind of you to offer. I've sent an image of the front and the back side.
The dent doctor was here earlier today to assess what he could do to flatten it out. He has to come back to do a bit more.
The holes are for the avery static port. The gun and bar bounced and the 2 horizontal indents just bellow the lowest rivet hole are where it bounced off the bottom of the avery static port disk.
Once flattened and re-enforced I'm considering cover below the static port with the ID plate. That or a decal because you can't really fill in when it's polished.

Cheers.


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