I just picked up a crown graphic in generally nice condition but I note that the back has a white powder in various crevices, but more importantly on the slides that hold the film holder. I don't want powder on the holders but don't want to have paint come off the affected areas - how do I best get rid of corrosion and how do I make the back smoothe for sliding in film holders?
Thanks

I suggest a medium or hard nylon bristle brush (old tooth brush) to remove the powder residue. Use it DRY.
Charles

Graflex advertising literature states that the backs are made of magnesium. The white powder you're seeing is magnesium oxide. From use the original black finish rubs through to the bare metal. If the camera is stored in a humid environment, the magnesium oxidizes to make the white powder. I've been successful in removing the powder using my fingernails or a wooden toothpick followed by vacuuming. Once everything is cleaned up, I paint the bare areas with a single coat of flat mate modelers paint and let it dry THOROUGHLY for a week or more in a warm area. So far I haven't had any trouble with the paint flaking but it will rub through over time from inserting and removing the film holders.