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?
Framebuilders/engineers - Aluminium bonding?
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 Shouldn't be too hard with a drop-out...
Loctite 638 is what's used on the Windcheetah trike and similar things, AFAIK.
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?
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...
I think you're going for a construction such as old Pace forks? To reiterate what bristolbiker said above, surface preparation is critical. 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).
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)
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