I have a devil of a time with the cast iron on tools getting a patina of rust in no time at all, even though I'm pretty good about keeping surfaces dusted and wiped down with a bit of WD40 (I avoid wax just because I have had contamination issues at finishing time in the past). Especially bad on the ways of my new, big lathe. The bed of that lathe is right in the heater's path.
I live in NE Missouri, so much of the winter is subfreezing, but only a few days of subzero here and there...
I have a suspended, high efficiency propane fueled heater vented to the outside and with good drains also to the outside in my 30x30 slab floor shop. I am not having a humidity problem at all - it's quite dry in the shop.
It has been my normal practice when not in the shop to set the temp at about 55...I spend some evenings and most weekends in the shop. The heater is probably oversized for my shop, it can bring the temp from 55 to 68 in about 7 minutes. I am wondering if I am inducing problems from keeping it so cool most of the time and then rapidly ramping up the temp. How much temp difference do you folks keep between unoccupied and working temps in your shops? Think I'm on the right track? I can experiment, of course, just hate to burn more propane than necessary when not in the shop.