Glueing brass to plastic?

[iBorg]

I need to add some small diameter square brass tube or aluminum to the inside of a body for structural support. I'm looking for the strongest joint possible. I'm thinking either epoxy or medium CA. Any thoughts and recommendations?

 

THANKS!

[Ace-Garageguy]

For "the strongest joint possible" use a slow-curing epoxy.

In general, the longer any epoxy takes to cure, the stronger the bond will be.

The stuff I use is made for aviation and takes a full 24 hours for a room-temperature cure, and develops maximum strength after an extended high-temp "post-cure".

That's insane overkill for a model, but I get it essentially free after it's gone out of date.

I'd recommend an epoxy that takes at least 30 minutes to set for your application.

NOTE: Bonding aluminum can be tricky. There are special modified epoxies made specifically for that because it's tricky and doesn't always stick well.

Test first, and use brass if you can't get a really good stick.

 

[Chariots of Fire]

Don't use aluminum.  Nothing seems to stick to it very well.  Clean brass will work with either 2 part epoxy or CA.

[Bainford]

It’s stronger too, and has better elasticity. Some of that aluminum tube is not very resistant to bending. 

[GLMFAA1]

I would suggest CA glue. I used it on this Sutphen ladder tower mating evergreen strips with brass L 's to form the aerial cage.

greg

[NOBLNG]

You could drill some small holes in the side of the tubing that gets glued to the plastic. That would allow the epoxy to ooze inside and really have something to hang onto.

[iBorg]

I appreciate the comments. Previously I tried aluminum with CA.  Didn’t work at all.  The idea of drilling holes in it with slow set epoxy may be winning combination.  

[peteski]

I would recommend regular JB Weld epoxy. The slow-setting stuff.  Or whatever epoxy Ace recommended would likely work even better.

The key to a strong bond is absolute cleanliness of the joint (both styrene and metal) and light scuffing of the surfaces.  I would scuff the metal (brass, aluminum, or other) and styrene with some 180 grit sandpaper, then clean/degrease the metal using acetone or lacquer thinner.  For plastic I would use a milder solvent like Naphtha, or even 91% (or stronger) Isopropyl alcohol.  After doing all that you should have a strong bond.

[Brizio]

I usually use  Zap glue.