best overall adhesive
- Thread starter wanna-be
- Start date
I have used epoxy as primary choice. Fiberglass, sand off any surface paint, clean with soap and water. Acetone will soften the superficial layer--and I only use it if the area is greasy.
The aluminum--wash with soap and water after sanding. Once over with acetone to get any grease off.
The aluminum--wash with soap and water after sanding. Once over with acetone to get any grease off.
wanna-abe
Gluing anything to aluminum is tough because it usually has an oxidized surface that comes off rather easily, breaking the bond between between the two materials being glued together.
When painting aluminum, (which involves a similar process in bonding as gluing), the surface needs to be roughed up with sand paper, and then etched chemically with an acid to remove any oxidation layer, then quickly dried and the paint applied before a new oxidized layer can develop.
Other problems one has to contend with are the fact tht the aluminum and fiberglass expand and contract at different rates when heated, and that they have different amounts of elongation when stressed or bent. Both of these problems tend to helf break the bond between the glue and the two materials.
My best advice is to screw, though-bolt, or rivet the aluminum and fiberglass together if at all possible. Mechanical bonding beats chemical bonding in this case.
I'll let others with more experience with adhesives recommend which ones to use. The best choice may well involve the exact application you have in mind, so I would suggest you describe in greater detail what exactly you're trying to do.
Hope this helps!
Joe. :teeth :thup
Gluing anything to aluminum is tough because it usually has an oxidized surface that comes off rather easily, breaking the bond between between the two materials being glued together.
When painting aluminum, (which involves a similar process in bonding as gluing), the surface needs to be roughed up with sand paper, and then etched chemically with an acid to remove any oxidation layer, then quickly dried and the paint applied before a new oxidized layer can develop.
Other problems one has to contend with are the fact tht the aluminum and fiberglass expand and contract at different rates when heated, and that they have different amounts of elongation when stressed or bent. Both of these problems tend to helf break the bond between the glue and the two materials.
My best advice is to screw, though-bolt, or rivet the aluminum and fiberglass together if at all possible. Mechanical bonding beats chemical bonding in this case.
I'll let others with more experience with adhesives recommend which ones to use. The best choice may well involve the exact application you have in mind, so I would suggest you describe in greater detail what exactly you're trying to do.
Hope this helps!
Joe. :teeth :thup
AstoriaDave
New member
What Bob and Joe said. Surface prep for the aluminum is critical.
Scratching around, the one 3M recommends for aluminum is EC2216, available in a duopack to give the proper mix ratio. From Amazon: http://www.amazon.com/3M-Scotch-Weld-Ep ... B000WXL090 You can buy this stuff in larger quantities, but the duopack will likely be enough for securing a plate, which is what you are doing, IIRC.
Other suppliers should have it also. Note that an adhesive which remains flexible after cure is required because the aluminum will expand and contract much more than the fiberglass. Ordinary epoxy will not withstand that. One source recommended Plexus, an acrylic adhesive, but 3M did not list an acrylic that I could see.
More details on the EC2216 (click on Product Information); note long curing time at room temp. This stuff is often used industrially with assemblies which can withstand oven heat, as in a couple hundred degrees F, to hasten cure. http://www.ellsworth.com/3m-scotch-weld ... l-duo-pak/
Scratching around, the one 3M recommends for aluminum is EC2216, available in a duopack to give the proper mix ratio. From Amazon: http://www.amazon.com/3M-Scotch-Weld-Ep ... B000WXL090 You can buy this stuff in larger quantities, but the duopack will likely be enough for securing a plate, which is what you are doing, IIRC.
Other suppliers should have it also. Note that an adhesive which remains flexible after cure is required because the aluminum will expand and contract much more than the fiberglass. Ordinary epoxy will not withstand that. One source recommended Plexus, an acrylic adhesive, but 3M did not list an acrylic that I could see.
More details on the EC2216 (click on Product Information); note long curing time at room temp. This stuff is often used industrially with assemblies which can withstand oven heat, as in a couple hundred degrees F, to hasten cure. http://www.ellsworth.com/3m-scotch-weld ... l-duo-pak/
AstoriaDave
New member
Good catch, ssobl. I spaced G-Flex. Definitely worth considering.
WEST offers an Aluminum Boat repair kit having all the stuff except the etching solutions needed for a couple small jobs, including thickener, mixing sticks, etc. Here: http://www.westsystem.com/ss/g-flex-epoxy/
They also tabulate data for bonding strengths for different materials, illustrating the effect of differing surface preps for aluminum, here: http://www.westsystem.com/ss/g-flex-epo ... sion-data/
I think the etch solution is critical for good adhesion. Their number 860-8 here, off the WM catalog: http://www.westmarine.com/webapp/wcs/st ... n1RN2jTnbU
And, G-Flex more likely available at a marine supply store than the 3M product I mentioned earlier.
WEST offers an Aluminum Boat repair kit having all the stuff except the etching solutions needed for a couple small jobs, including thickener, mixing sticks, etc. Here: http://www.westsystem.com/ss/g-flex-epoxy/
They also tabulate data for bonding strengths for different materials, illustrating the effect of differing surface preps for aluminum, here: http://www.westsystem.com/ss/g-flex-epo ... sion-data/
I think the etch solution is critical for good adhesion. Their number 860-8 here, off the WM catalog: http://www.westmarine.com/webapp/wcs/st ... n1RN2jTnbU
And, G-Flex more likely available at a marine supply store than the 3M product I mentioned earlier.
Jack in Alaska
New member
Look into an adhesive product called SILASTIC. It is a great adhesive and I used it successfully sticking aluminum plate to fiberglass on my RV.
srbaum
Member
Without over thinking this, I had great success attaching a fiberglass plate to my (aluminum hull) pontoon boat for the transducer using 3M 5200. It was still well adhered to the boat when I sold it 8 years later.
I did prep both surfaces by cleaning the hull surface of the pontoon boat and the fiberglass block, prior to the application. I used tape to hold the fiberglass plate in place for several days, before installing the transducer.
I did prep both surfaces by cleaning the hull surface of the pontoon boat and the fiberglass block, prior to the application. I used tape to hold the fiberglass plate in place for several days, before installing the transducer.