I wasn't going for durable, though -- I like that shellac is easy to remove completely. Plus it has a subtle yellow tone to it that makes it look like my frame was dipped in liquid golden sunshine and then polished. It brings out all the brass brazing.

I do regular maintenance on all my bikes and if it chips off a little then I'll just brush more on. I dunno, I'm just sharing an experiment. I'm not advocating a way of treating a bike frame. To my knowledge, no clear coat of any kind is enough to protect un-primed steel from rust.