cleaning vintage Cadex carbon and aluminum lugs and joins
 

Just got this nifty old Cadex carbon frame with aluminum joints.
How would you suggest I clean the white gunk off the aluminum joints? vinegar? fine steel wool?
where would it have come from ? too humid storage?

Can't tell for sure, but usually the powdery white stuff that forms on polished aluminum is a form of oxide. In my experience it's usually because of exposure to salt, but might happen without salt being there.

Aluminum is corrosion resistant (not corrosion proof) because it forms an oxide skin which prevents further corrosion. Cleaning it off with abrasive, and certain polishes is counter productive because it exposed the reactive base metal leading to more corrosion.

If you want you can use a cleaner wax which will remove the loose stuff, and leave more protection on the lugs. If you expect exposure to the elements, or your own dripping sweat, rewax the lugs fairly often to keep them bright.

I agree with FB that harsh abrasives should be avoided. A fine Scotchbrite pad should remove the loose stuff, followed by a good paste wax as a protective layer. Don't try to get a mirror shine, just get the joints clean and free of the buildup.

Aluminum does spontaneously form an oxide layer that self-protects it but the layer is thin and can be damaged by salt or other chemical contact and discolored by prolonged water exposure. A much thicker and more protective oxide coating is created by "anodizing" but that's not a DIY process, particularly not on a built-up frame.

I am not familiar with "Cleaner Wax". is this a bike thing or a general car maintenance product?

Car thing, aka self cleaning wax, one step wax, or something similar. Some are only cleaners, some have very fine polishing compound to de-oxodize the paint finish for brighter color. Either is fine but don't get carried away with the ones that are abrasive.

I'd guess the bike is clear-coated, and the corrosion is a result of damage to it. In which case, making it pretty again won't be simple... not sure what else to add.

BTW: I had a CFR1, which is pretty much the same as this, and it had a 135mm OLD. If yours is the same, you can stop squeezing the stays and have a stronger wheel with less dish if you add a 5mm spacer under the left locknut (you may be able to get away with using the 130mm spindle by moving it 2.5mm to the left).