After a good cleaning, wipe the whole gun down with wax. I have never had any problem with Johnson's Paste Floor Wax, but have switched to Renesance Wax (what museums use a lot of and reported to be acid free) recently (it is a lot more expensive, so must be better, right?). Wax is a solid and will not run or wipe off. It is also a good metal and wood protectant for normal use; just shine 'er up when you finally pull 'er outta the safe.