I keep two old box knives in the kitchen junk drawer. One has a regular blade on it, and the other has a hooked blade because I think they’re safer and run less risk of damaging the stuff inside the box. But sometimes, you just need a regular box knife. They’re both old and handle rough, but they have seen a lot of use.

Last night I was painting. While trimming some masking tape against a hard edge I realized the blade on the regular box knife was a bit dull, so I went to change it. While flipping the blade around to the unused side, I noticed there were no more spare blades in the handle.

Today I bought a new pack of blades. They purport to be better quality and will stay sharper longer than the original set of blades that came with the knife, but I guess we’ll see how that holds up with use.
While adding the new blades into the handle, I decided to go ahead and clean up both knives - get all the tape residue out, and clean the internals. Then I gave the slightly rusty patina’d slide mechanisms a couple drops of 3-in-1 oil. I also gave the blades in the handle a drop along their sharp edges for good measure.

They open and close very satisfactorily now.