Tom, I heat my shop with a propane gas heater. It's true when the heater heats up the shop it creates a lot of condensation. When I first started using the heater my table saw and bandsaw and jointer started getting surface rust. I cleaned evrerything up and purchased some HTC Machine Covers from Woodcraft. The covers come in Small to Jumbo and since I started putting paste wax on the tools surfaces and using the covers i have had no rust problems. The problem is the covers are not that cheap but they are very good covers. I leave each tool covered and only uncover when I need to use it. I do this all year round. The perfect solution would be to get the Sterling or Hot Dawg but if you cannot then the covers really do help keep the rtust away.
Life Sure Is Great! Enjoy It.