I have a damp basement and it's creating problems with my steel tools. Will a light coat of car wax keep them from getting surface rust, or is there another recommendation?
The best rust preventative I have used is Boeshield. Spray it on let it dry then buff off the excess. We use it on machine tables that are infrequently used.
Now for garden tools my uncle kept a bucket of sand that he would mix in his used oil from the lawnmower and tiller. He would dip his shovels, hoes etc in the just dampened sand and it would lightly coat the tools. Some like shovels he would leave in the bucket until next time.
Caution: the EPA says that used motor oil has components that can be considered carcinogenic. It was 50 years ago and he was recycling.
A trick used with garden tools is to put oil soaked sand in a bucket, and then plunge the tools into the sand for storage. Might not be a good idea for tools with "threaded elements", though.
WD-40 will kind of prevent rust, for a short time. Remember it is basically kerosene and it evaporates fairly quickly. Its main mission in life is to disperse water based machining coolants to prevent flash rusting between operations and before finishing. We use a ton of it in the machine shop for this use and it works great. Its also a great cleaner! It is NOT a lubricant although it works well for tapping threads in Brass.
Long term storage you will do better with a wax layer, especially on wood working tools where oil could stain the work. For chisels and the like Carnauba wax does pretty well.
The Boeshield is more or less a wax that is dissolved in a carrier solvent. Spray it on and let the solvent evaporate and buff off the excess. There was an in-depth test on a cast iron saw table done in a humidity chamber a while back. I think it was Fine Woodworking Magizine perhaps. They applied a bunch of products to squares on the table then blew moist air on it. The WD-40 held up for about an hour, IIRC the test was terminated before the Boeshield area showed rust!
The interesting thing comparing WD-40 and Boeshield is that one was developed for Convair and the other by Boeing.
The other thing Boeshield works great for is lubricating roller chains, like on a bicycle.
Another great product is LPS-3 heavy duty rust preventer. I don't like it as much as it seems to be gloppy and doesn't cover as well. We use a lot of Boeshield. At least in a machine shop we aren't so concerned with oil mucking up the workpieces. We only have to worry when running certain plastics like Teflon and porous phenolics that the customer wants uncontaminated.
Never said it wouldn't work if your conditions allow. But for the OP's uses there are way better choices then WD-40. I'm glad in your situ it works, but the steel rack in the back our our shop sure doesn't stay rust free with WD-40!