Samwiches

I stripped an aluminum frame, built up this bike and since everything seems great, and light, I'm ready to put it back up and protect the frame.

Originally I was going to spray a light clear coat--I was about to clean it up but I like how the dust oxidizes(?) into a sooty, ridden look.

So I gave it a light rub with a tack cloth and the look stays. Will the oxidation spread under whatever clear I apply? What about the integrity of the coat afterward? Will it stay?

Servo888

I would polish the aluminum, and use a sealant (sometimes comes with the aluminum polish). I'm not aware of anyway to paint a clear coat on - you could, but it would be brittle. Most people apply a sealant (such as Zoop: https://www.zoops.com/zoopseal.asp ) to protect the finish. But you need to reapply it every year or so.

I polished an old campy headset once... With no protection, it still looks okay a year later.

Ronsonic 

If you like the raw aluminum look don't clear coat it. It will only get so funky before the oxidation gets to a point where that funky gray patina (rap it to the tune of "funky cold medina) sort of puts a stop to itself and in the absence of weird chemistry it won't get any nastier. I've got a mountain bike frame I stripped three years ago it still looks pretty much like yours does in that photo.

It's oxidized, what is there to "protect?"

rodar y rodar

OT: Do Campy headsets generally have that sprocket shape, as posted above by 888? I`ve never seen any like that before, but then again- I`ve never had the pleasure to hang out with a lot of Campy stuff.