My shop has no heat, no cooling, and no humidity control. The atmospheric humidity here runs 75-80% year-round.
In the winter in my basement I have to run a dehumidifier almost 24/7. I have the coil connected to a temperature sensor. Once it drops below 35 the coil ices over it shuts it off until the temp is above 50.
In the summer the dehumidifier in combination with the summer heat there isn't enough temperature delta to get the dehumdifier to condense. I end up also running an air conditioner. The mechanics of an air conditioner and dehumidifier are the same, only the air flow is different. Once the A/C is running it condenses out some water and the dehumidifer kicks in. I usually pump out 70-80 pints per day (4-5 gallons) during the summer.
I don't know what the exact RH is, but if it feels humid to me then it probably is too humid for the tools.
Until this weekends storm the humidity level 140mi east of our Bay Area respondents has consistently been in the 15% +/- range. Having received 15” of rain over the last week, yippee, I can joyfully report that it is a comfortable 74% this morning and time to go over the CI tool beds.
Derek, you're 100% correct on the "why". Unless someone is running AC in your shop full-time Spring through Fall here in TX, there is gonna' be some rust. To varying degrees, but unavoidable. I've never seen a machine that doesn't have some level of rust to it. This being said, you shouldn't have any problems with rust on the cast iron tops so long as you are waxing them routinely. At least I never did.
Erik
Ex-SCM and Felder rep
Several commenters on this thread mention that they do not monitor shop humidity. I do and find it useful to protect from rust. This monitor is only $10.99, has thermometer and hygrometer plus max/min function.
https://www.amazon.com/ThermoPro-TP5...pt=THERMOMETER
Something just popped into my head: Our edgebanders comes with several of these things stuck to the inside of the working compartment: https://www.zerust.com/products/vci-...ule-diffusers/
I had no idea about them prior to coming back to Felder and haven't seen them used on any other machines (the glue fumes are probably corrosive to raw metal) but if someone was really worried, they're available on Amazon. Seems like the company offers a bunch of rust preventative solutions.
Erik
Ex-SCM and Felder rep
I have a few of those that I throw into the drawers with tools and chisels/rasps/router bits, etc... Plus some rechargeable desiccant containers. Despite AC running essentially 14/7 in my workshop, it's impossible to really lower humidity to a level that would prevent rust.
Keeping the rust at a small but manageable level is my goal. It does bother me, but it is what it is living on the water.
- After I ask a stranger if I can pet their dog and they say yes, I like to respond, "I'll keep that in mind" and walk off
- It's above my pay grade. Mongo only pawn in game of life.
My woodworking shop is not climate controlled other than it's insulated. It is way better up here than central MS where it would rain inside occasionally. My laser room is my basement and it's dry and stays between 25 and 40% like the house. I did install minisplit that I use mainly for heat and I could use to eliminate moisture if it was an issue.
Woodworking, Old Tools and Shooting
Ray Fine RF-1390 Laser Ray Fine 20watt Fiber Laser
SFX 50 Watt Fiber Laser
PM2000, Delta BS, Delta sander, Powermatic 50 jointer,
Powermatic 100-12 planer, Rockwell 15-126 radial drill press
Rockwell 46-450 lathe, and 2 Walker Turner RA1100 radial saws
Jet JWS18, bandsaw Carbide Create CNC, RIA 22TCM 1911s and others