View Full Version : Aluminium adhesive

12-09-2013, 09:47 PM
Just about to assemble the gantry (50x100x6 aluminium box section). I was originally going to bolt it together, but now may have it welded. But unsure of welding due to possible distortion so was wondering if anyone has used any form of adhesive to join aluminium?
If so what adhesive and how well did it work. Does it reduce flex over bolting the box section together. Will welding them distort?

12-09-2013, 10:30 PM
Same question myself, there seems to be plenty of choice re. adhesive but as you say first hand experience feedback is required.

12-09-2013, 10:39 PM
Don't know about adhesives, but I think welding will cause even greater distortion than with steel. G.

12-09-2013, 11:48 PM
You could always try Durafix brazing sticks, I've just bought one to try!

12-09-2013, 11:52 PM
When I built my router (primarily to make PCBs) out of aluminum, and not having access or the ability to TIG, I chose to bolt and use Loctite E-20NS adhesive.
That has been a couple of years now and the machine is still "glued" together!
Along the line, I have also done some milling and engraving of aluminum and brass! YMMV, but I am sold on it1

13-09-2013, 12:02 AM
Wouldn't weld it together aluminium distorts something silly when welded and then it will be stressed so will start changing shape when these stress's release over time.!!. . . . Just bolt it together with adhesive like Loctite or epoxy.

13-09-2013, 12:13 AM
Have a look at Structural epoxy.
3m make a good range.
They bond Ali, Steel and other stuff.
check out this lo-tech, but impressive demo.
DP-420 3M EPOXY overlap shear test by Doctorbass PART 1 - YouTube (http://youtube.com/watch?v=3NWzODqhSbw)

it aint cheap tho, surprisingly :disillusionment:

Edit: There are now room temperature versions that are very nearly as strong.

13-09-2013, 09:33 AM
That's the key word 'structural'

13-09-2013, 12:45 PM
As I understand it, surface prep is the key (pun unintended) to glueing aluminium - do exactly what the instructions that come with the glue say and if you can't (temperature constraints etc), find a different glue.

I would use enough bolts to put it on the skimpy side of ok without the glue and use the glue to provide a safety margin and extra rigidity. Doing it this way you might not need such fancy (expensive) glue.

I was thinking of using a medium strength loctite for the rail and linear bearing contact surfaces - one that would be separable if necessary but would stop any slippage.

13-09-2013, 10:44 PM
Thanks for the input guys. I will go with the bolt & adhesive option then. Will go for a loctite structural epoxy, grade tbc.
I'm guessing the entire surface won't have to be coated only dabs equally spaced across the area?
With the fixings to bolt the ballscrew bearings on etc do people tend to loctite these in due to vibration or use spring washers or nothing at all

14-09-2013, 12:38 AM
With the fixings to bolt the ballscrew bearings on etc do people tend to loctite these in due to vibration or use spring washers or nothing at all

Spring washers are my preferred choice.

18-09-2013, 08:08 PM
I do a lot of bonding things together ,think things that pull lots of G's

Bonding would be a great way to go with some rivets in there also

Remember aluminium is filthy to glue together ,the same oxide layer that likes to form to stop it corroding regardless you need to etch it and prep and for high end applications actually convert the surface to a different layer substrate, clean it and degrease it scrupulously if you do not have access to acid etch or anodic treatments ,the strongest adhesive is useless if it cannot get purchase on the alloy

Dabs of glue? bonding rlys on film thickness ,called a bondline dabbing blobs will cause unevenness you need a uniform bed of adhesive ,dont think of it as liquid nails unless your doing your skirting boards

Also aluminium rivets act as mechanical fuses should your glue decide to divorce itself from the aluminium will not allow you to apply forces that will distort the joint

09-11-2015, 09:40 PM
Although the thread is really old, maybe someone is still interested in these theme.
I used a heatadhesive for aluminium from the german company delo.
the only disadvantage of the ad. is, you must heat the parts for at least 1/4hr to iirc 150C.
After that, you can never open the connection.