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Structural adhesive for Aluminum

Stewbronco

Well Known Member
Hi .....have some experience with this on Corvette race car ( very successful) and familiar with PRO SEAL ..but looking for advise on a good readily available structural adhesive for aviation use . Any real world experience ( sure there is ) and tips would be appreciated. Many thanks. Stew
 
Hi .....have some experience with this on Corvette race car ( very successful) and familiar with PRO SEAL ..but looking for advise on a good readily available structural adhesive for aviation use . Any real world experience ( sure there is ) and tips would be appreciated. Many thanks. Stew

I agree that the big names like 3M will probably have what you need. To get more specific, it might help to understand your application. There are not many places in an RV build where adhesive is the only thing holding two pieces of aluminum together. On my aircraft, there are none.
 
I agree that the big names like 3M will probably have what you need. To get more specific, it might help to understand your application.

Need to know application.
Application? major, safety critical structure or secondary structure? all in sheer or are there pull-off loads?
Environment? Moisture? temperature changes? fuel? vibration?
 
Easy

Ec2216 is the industry standard, but prep is everything. So bonding airplane parts is not like model airplane building, be informed.
 
Go do a little searching in the Bede aircraft world on the inter webs - they glue a lot of structure together!
 
3M 5200

3m 5200 is amazingly strong and bonds very well to metals. Scotch bright and clean as prep. Home Depot sells it in a small tube. Get the quick cure. Be aware it is a permanent bond. I used it on my flap and aileron trailing edges. Easier to use then pro-seal but equally messy. Wear gloves.
 
3m 5200 is amazingly strong and bonds very well to metals. Scotch bright and clean as prep. Home Depot sells it in a small tube. Get the quick cure. Be aware it is a permanent bond. I used it on my flap and aileron trailing edges. Easier to use then pro-seal but equally messy. Wear gloves.

The tech data I saw mentions several materials this works on, but none are metal. Any idea why? Corrosion? Adhesion? Liability?
 
design Life

These RVs are designed for thirty years. I think one is better off using the tried and true EC2216. easy enough to get, and is a known quantity for structural work.
 
I've used 5200 and 2216 and for airplane use, I'd use the 2216. The data sheet gives properties for it with our materials, including bonding to acrylic. I followed 3M's process with 2216 when I used it to attach my canopy. No screws, just 2216.

I hated working with the 5200. It would tend to flow away if the joint wasn't perfectly level, and on my boat, little was level. It stuck to me better than the boat, it seemed. Give me some good old 2216 or West System's G/flex instead.

Dave
 
My first build was an Avid Flyer (the original design that developed later into the kitfox, Montana Coyote, Just Highlander, Savanah etc....). It's wings were 6061-T6 aluminum tubes for spars with finish birch plywood ribs. Two-Part 3M Scotchweld 2216 was the structural adhesive used to bond the ribs to the spars. At Boeing we called it BMS 5-92 structural adhesive and it is used extensively on Boeing airframes as a faying surface sealant and structural bonding adhesive. The Avid builders called it "Gorilla Snot". It is a very good adhesive and when cured actually has a bit of pliability.

2216 needs to be mixed correctly (parts A and B) and the metal bonding surface needs to be etched and then squeaky clean. The Avid kit had a degreasing agent that was very volatile (felt cool to the skin like alcohol) and when spread on the aluminum it dried within seconds leaving a white powdery coating. That coating was wiped off yielding a ready-to-bond metal surface. Caution was labeled to not touch the surfaces with fingers to avoid contamination.
 
Many thanks

2216 it is …had a very informative phone conversation with a VAF member who has done extensive testing of riveted joints and 2216 and I am not only impressed with his manner and knowledge but along with the recommendations here the decision became easy. Cheers. Stew
 
I used 2216 on many things over the years. It's thick enough to stay in place, has a good shelf life- years and the bond is impressive.

Aluminum oxidizes rapidly- in minutes, so surface prep and cleaning for ANY bonding process is paramount for maximum joint strength.

In making sensors with bare aluminum bodies, these are water scrubbed first and then acetone wiped 1 minute before bonding with epoxy. I've made thousands of these. Nothing peels off if done right with some of these in service for over 25 years.
 
Need to know application.
Application? major, safety critical structure or secondary structure? all in sheer or are there pull-off loads?
Environment? Moisture? temperature changes? fuel? vibration?

I could see adding some adhesive in areas where smoking rivets might be common. Anything to prevent this movement or fretting would probably be beneficial.

Where are the most common places for smoking rivets? Control surfaces? Belly skins?
 
Ask Vlad

I could see adding some adhesive in areas where smoking rivets might be common. Anything to prevent this movement or fretting would probably be beneficial.

Where are the most common places for smoking rivets? Control surfaces? Belly skins?

We should ask Vlad. He has one of the highest time RV9A's out there.
 
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