Forum menu
Framebuilders/engin...
 

[Closed] Framebuilders/engineers - Aluminium bonding?

Posts: 6926
Free Member
Topic starter
 

Hi
I'm about to start making the forks for my little girl's balance bike and want to bond 2 pieces of aluminium tube.
I'm using an old fork csu but need to bond some dropouts to the bottom of the stanchions to enable me to fit the wheels.
Anyone know what I would need?
Thanks
Steve


 
Posted : 03/12/2013 11:10 am
Posts: 0
Free Member
 

I've used toughened 2-part structural epoxies with good results (something like 3M 9323, though the price of a 1 ltr kit for a single joint may be prohibitive!). The key is surface preparation - degrease as a minimum, grit blast as well would be better..... a proper surface primer or an acid etch would be best so you are bonding to the aluminium itself, rather than the oxide surface layer....

EDIT- Oh and design of the joint is obviously quite critical, and if you can design in some mechanical redundancy, that would be great ๐Ÿ˜‰ Shouldn't be too hard with a drop-out...


 
Posted : 03/12/2013 11:14 am
Posts: 0
Free Member
 

Loctite 638 is what's used on the Windcheetah trike and similar things, AFAIK.


 
Posted : 03/12/2013 11:23 am
Posts: 0
Full Member
 

Slight hijack, but I have some old x-lite bar ends which have become unbonded, but always had a nice shape for fire road cruising. Would you recommend locktite too, or is there something else which fits the bill?


 
Posted : 03/12/2013 11:44 am
Posts: 6926
Free Member
Topic starter
 

Thanks for the replies guys.
I emailed Loctite too to get some info off them and it appears that 603 or 638 are the tools for the job. Luckily I've got some 603 available at work so will be going that route...


 
Posted : 03/12/2013 12:21 pm
Posts: 4278
Full Member
 

I think you're going for a construction such as old Pace forks? To reiterate what bristolbiker said above, surface preparation is [b]critical[/b]. Make sure your design is up to scratch, you have a good (small) gap between the diameters you're trying to bond and a decent length in contact i.e. rough guide: absolute minimum of L = 1.5 D).


 
Posted : 04/12/2013 12:07 am
Posts: 6926
Free Member
Topic starter
 

Thanks mate. I'll be aiming for a 0.05 - 0.1mm gap as suggested by Mr Loctite.
I'll have approx 70/80mm of contact area on the tubes (36mm OD)


 
Posted : 04/12/2013 12:11 am