I have two instances of nice steel tools rusting when I put them in wood containers. Here they are:
1. I bought an unfinished softwood box to hold my Starrett combination square set. It is similar to this, from the same guy. Mine is not maple - it is very soft. The only finish is an etched decoration on the cover.
2. I made an end cap for a 1/2 inch chisel from some hard maple scrap. I cut a 1/2 inch dado on one side, then glued a flat piece on top. The chisel slides in the hole created by the dado.
In both cases, the steel tools got rusty within weeks of being put in their wooden containers. The chisel had stayed rust free for years until I stored it, in exactly the same place in the same tool drawer, but with that maple cap attached. I made the cap only a few weeks ago.
I live in Southern California. Most of the time (especially in summer) the air is very dry.
It was easy to remove the rust from the combination square set - I used Scotchbrite pads with a little 3-in-1 oil. I haven't tried the chisel, but will probably put it on the sharpening stones to clean it up.
HERE ARE MY QUESTIONS:
1. Am I right in assuming that moisture in the wood caused the rusting?
2. Is there something I should be doing to prevent the rust?
3. Is proper finishing the answer? If so, what should I use? Can I coat the inside of the chisel cap with it?