That's a great suggestions. I still have some RPM that I'll try your idea with. Scott Smith (Harms) also suggested with the SEM bolts (captured washers) that a soak in Evaporust after the wire wheel / media blasting might get even more of the rust off from under the washer. Then a quick rinse and dry off before the Black Oxide should work really good.
Both those ideas are great. Thanks for sharing those! I love to learn new ways to do it.
pro video ,nice job!
I have used the caswell product on my last couple restos and i prefer to use rpm instead of the caswell sealer or wd40 for a flatter more durable finish,just my experience...