Bonding steel and aluminum, or aluminum and wood

[funcit]

hello all.

im new to the forum, and new to working with metal. im looking forward to learning a lot!

my first question is a very basic bonding question.

i have a flashlight made of anodized aluminum. i want to bond the aluminum to a piece of steel or wood.

for either case, which kind of adhesive should i use? so far i've only tested the wood piece with super glue, and average 2 mix epoxy from the hardware store. both did not bond very well and i was able to snap the piece off....

i would greatly appreciate some suggestions.

thanks!

 

[Compositepro]

Wood expands and contracts a lot compared to metal. You cannot prevent this so you must allow for it in the bond line. That means using a thick bondline (like 1/8" or more) and a very flexible (rubbery) adhesive. Silicone or urethane adhesives would be more appropriate. With a large bond area flexible adhesives can appear to be very strong and stiff.

 

[funcit]

ok,

now what about steel to aluminum. is there something super strong going on there?

i think id rather do that.

would also love to know how it could work cause metals are not pourous, hard for me to imagine 2 metals being bonded strong with an adhesive, but i know it just has to exists.

thanks!

 

[roger78]

Hi Funcit,

Yes you can bond metals. What do you think what will be used in de aircraft industry or automotive. There are many kinds of metal bonders. You'll need an acrylic based 2 component adhesive.
Look here:

http://www.ellsworth.com/display/productlisting.html?ProductLineID=12&SubcategoryID=32&Tab=Products

There is Lord Adhesives, Loctite, 3M, Parson Adhesives, Defcon, Bostik...all the leading adhesive manufactors

good luck!

 

[btrueblood]

Depending on the flashlight brand, you may have to remove the anodizing to get a good bond. Some anodizing is given a secondary polymer "sealant", dunno how well this affects strength of bond, but doubt it would do any good. Try abrading the flashlight down to bare metal and re-try with a good epoxy (flexible epoxy or urethane probably not a bad idea as Comppro suggested). Don't bother with silicone, imo.