S

Schwemmer

Member
I attended a radio control club meeting the other night and the topic was a model of the RV 4. The speaker mentioned that the first kits had the metal skins "bonded" instead of using rivets. I do know that there are bonding agents and some airplanes use that instead of rivets. Would it be possible to use bonding adhesives instead of rivets on the RV7? would it make the overall gross weight lighter? Has anyone researched this?

Thank you,
Rick
 
interesting

This is interesting. When I told my glass man I was building a plane and using pounded rivets, he asked me if I was going to use adhesive. I didn't even know that was an option. I asked Vans and they said it wasn't needed. Using adhesives instead of rivets didn't cross my mind. On the weight difference, I can't imagine anything being lighter than rivets. Glue or epoxy is pretty heavy. IF if worked, the benefit possibly could be less drag? From what I have been reading about Vans RV 1, it looks like they used rivets on that plane.
 
Just to clarify, the speaker was referring to the first kits of the model, not the first kits of the RV-4. No RV-4's have been built with adhesives instead of rivets, to my knowledge.
 
Snowflake said:
Just to clarify, the speaker was referring to the first kits of the model, not the first kits of the RV-4. No RV-4's have been built with adhesives instead of rivets, to my knowledge.
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Does the RC kit actually have metal wings? The Great Plains 1/4 scale one is wood...

Perhaps he's confusing it (the 1:1 scale one) with the similar shaped wings of the Grummans, which do have bonded metal wings....:)
 
RV or BD

Schwemmer said:
I attended a radio control club meeting the other night and the topic was a model of the RV 4. The speaker mentioned that the first kits had the metal skins "bonded" instead of using rivets. I do know that there are bonding agents and some airplanes use that instead of rivets. Would it be possible to use bonding adhesives instead of rivets on the RV7? would it make the overall gross weight lighter? Has anyone researched this?

Thank you,
Rick
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It sounds like the speaker may have mixed up the RV-4 with the BD-4 which I believe was bonded construction.

Skylor
 
I always thought the bonded wings of the Grumman planes would start having delaminations and an AD by now.
Just goes to show you what I know...:p
Once I learned how to rivet sheet metal I started to think it's a pretty good system.
Could you imagine an airplane put together like your fuel tanks :eek: minus the rivets, of course.
 
SHIPCHIEF said:
I always thought the bonded wings of the Grumman planes would start having delaminations and an AD by now.
Just goes to show you what I know...:p
.
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As a Grumman refuge (there are many of us here....), I can tell you that there WERE some debonding issues in a couple of early production years - and it was quite a headache for some. But in general, yes - the airplanes have surprised their critics....and trained many a future RV builder/pilot!
 
In the big-airplane world, we do indeed bond skins with adhesive. However, it's typically only large doublers to skins, which then get rivets all the way through the stack-up.

Metal bond uses a film adhesive rather than a liquid "glue". The preparation for the skins prior to bonding includes, as a necessity, anodizing and a special bonding primer applied by a machine for uniformity. The layup happens in a cleanroom and then goes to an autoclave for curing, much like composite materials. After cure the whole thing gets NDI'd for any disbonds, voids, or porosity in the bond line.

Rivets we can do in our dirty garages.
 
There was a kit for sale a few years back that was advertised on e-bay and other site. I think it was called the "bulldog" or something like that. It was a two-seat sheetmetal plane based on an existing design (can't remember which). When first advertised, they touted bonded skins, later that changed to pulled rivets, and then they went away. I spoke to the owner of the kit on the phone once and looked over his build log (his wasn't bonded) nice guy, but I wasn't impressed by the kit.
 
Bonded skin vs. home building.

Originally the Moni Motorglider had bonded aluminum wing skins. They did have a lot of de-lamination problems.
Part of the problem is that the process of "bonding" aluminum is NOT forgiving and most home builders do not have the proper facilities. Bonding aluminum in a well controlled factory is one thing. Doing it in a garage is quite another.
 
I just finished my first annual on my C182 and was surprised to see that all the leading edge ribs were bonded to the skins. I always knew that Cessna had smooth leading edges, but it never occurred to me that they were bonded. The rest of the wing, of course, uses drag inducing raised head rivets.:(

As far as bonding an RV, even if we had the facilities to do it, we'd have to deal with all of the pre-punched holes. Way too much work for me to figure out. I'll keep smashin' rivets.

Brad
 
Mel said:
Originally the Moni Motorglider had bonded aluminum wing skins. They did have a lot of de-lamination problems.
Part of the problem is that the process of "bonding" aluminum is NOT forgiving and most home builders do not have the proper facilities. Bonding aluminum in a well controlled factory is one thing. Doing it in a garage is quite another.
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However the RS-15, HP-16 and HP-18 homebuilt gliders of the same era have bonded aluminum wings that are much longer (15m) than the Moni.

These were garage built and are stlll holding up - even Van used to own one...:)
 
I am new to this forum and have spent a number of hours going through most of the threads. I have seen a very large knowledge base of many topics. So when I head of the speaker relate how the first full size Rv's had used bonding adhesives instead of rivets, it made me sit up and take notice. I never read or heard of any RV plane using bonding adhesives. As for the RC kit you are correct. It is a wood and plastic covered plane with not one rivet to be found on it.

Thank you to all for the great information. I am just trying to learn all I can.

Rick
 
To my knowledge, no one has actually bonded an RV (not to be confused with faying, where a joint is bonded and then riveted). But it has been talked about before, so I would not be surprised if someone has tried it. It has never been part of the kit instructions, early or late. I suspect your speaker misspoke or was talking about something else.
 
krw5927 said:
In the big-airplane world, we do indeed bond skins with adhesive. However, it's typically only large doublers to skins, which then get rivets all the way through the stack-up.

Metal bond uses a film adhesive rather than a liquid "glue". The preparation for the skins prior to bonding includes, as a necessity, anodizing and a special bonding primer applied by a machine for uniformity. The layup happens in a cleanroom and then goes to an autoclave for curing, much like composite materials. After cure the whole thing gets NDI'd for any disbonds, voids, or porosity in the bond line.

Rivets we can do in our dirty garages.
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The original AV-8A Harrier has bonded flaps with al aluminium honeycomb core. In the 60s the NDT techniques weren't great, so no-one worried about dis-bonds. Many years later when the production location was moved the first flap produced NDT, and many dis-bonds were discovered - took ages and a quite different production technique to get the bonding sorted out. The suspicion was that the originals were all dis-bonded to some extent but no-one knew. The conditions in out dirty garages are probably worse than a 60s or 70s aircraft factory, so I don't think I would risk bonding my RV together.

Pete
 
penguin said:
......
The conditions in out dirty garages are probably worse than a 60s or 70s aircraft factory, so I don't think I would risk bonding my RV together.

Pete
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Again, reference RS-15, HP-16 and HP-18 homebuilt gliders of the same era with 50 ft bonded aluminum wings.

These were garage built and are stlll holding up, even 20 to 30 years later - even Van used to own one that he didn't build...:)
 
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