A couple of weeks ago I found my old Dovo Special razor, bought in the eighties of last century, covered in rust. I hadn't used it for a while because it is very hard to hone. I removed most of the rust with a little wire brush and started to grind it to remove the burrs etc. Unfortunately, within 24/24 there was rust again on the freshly ground cutting edge. The razor was really dry before being put aside in a really dry room. I keep my working razors in a less dry bathroom and they do not seem to come to any harm.

Can anyone tell what causes this accelerated rusting? And what to do about it?