by John McComas
All you really need is non-detergent oil. You can get a quart from an
parts store or maybe even Wal-Mart. Obviously, a quart would last you a lifetime
unless you took baths with it.
20 SAE is the recommend viscosity and is referred to as "20 weight non-detergent oil."
Automotive oils have "detergents" which is bad for electric motors.
Detergent oils clean the crud off of components, the crud then circulates through the
porous bearings (which is a major part of the oil recirculation system), eventually
stopping up the pores, eventually causing a loss of the oil film separating the
shaft and bearing, eventually causing bearing and/or shaft wear, eventually
causing a loss in the air gap between stator and rotor, eventually causing the
motor to electrically or mechanically lock up, causing a fan that just sits there
and hums. DON'T USE DETERGENT OILS.
Your 100-year old fan motors didn't use it.
Don't forget to read Scotty's article on fan lubrication:
The following lubricants are very good:
1. Royal Purple Synthetic INDUSTRIAL oil ISO 68 ~ SAE 25
(I'm thinking about trying some RP ISO 32 ~ SAE 15 for single bearing Emersons)
2. Zoom Spout Oiler with Unocal 76 turbine oil (used by HVAC people and has good dispenser)
ISO 32, SAE ~ 15 Lighter weight, (several collectors like using it)
Check your hardware store... 4 ounces for $2 - $3
3. 3 in 1 "Motor Oil" in the BLUE can, NOT the "Multi-Purpose" Red container.
SAE ~ 20 (both are non-detergent, ONLY buy the BLUE can!
(The red can has Naptha. Not recommended. The Naptha gets the dirt in suspension
then evaporates leaving dirt on the bearing surface, like detergents)
Chain stores Lowes, Home Depot, may stock the BLUE "3 in 1 Oil"
I've been through the RP grease. (I was one of the first to warn people
ago of its bad separation properties)
I've used that black nasty moly lube grease. Stay away from that stuff!
I've used wheel bearing grease. It's OK.
My new best favorite, no mess, works great grease is white lithium aerosol sprays
with a little red spray tube.
I clean out the old grease, turn on the fan, and spray the gear faces.
Works great, and no mess. I also squirt it into oscillator linkages. Easy to wipe off.
You DO need to shake the can up well before applying...
Ace Hardware shows 3 different brands of aerosols. Dupont, the creators of Teflon,
adds Teflon to the lithium. (I haven't tried that yet, but sounds like it would be great since Dupont makes quality products.)
Here's a viscosity chart you might also find helpful...