Longer lasting bronze bearing rehab for box fan...

[porterdog]

Hiya,

I use a really nice old box fan for whole-house ventilation during the dog days of summer. It's three-speed, reversible, and has a thermostat and a baffled box for efficiency (meaning that there's a sheet in the box with a circular hole in it to close up the box around the fan blade...)

It's pretty old, and the felt wicks that used to supply oil to the shaft have disintigrated. Consequently, it gets dry every now and then and locks up, with predicable results on the shaft. They're still smooth, but the chrome is coming off and the TBO is dropping...

I'd been using M1 10w30; that would last a couple weeks before the fan wouldn't turn back on after I stopped it. Redline CV1 grease lasted a month.

I had to regrease again last night; it's getting old, but this fan really has a nice set of features that I've not seen in the MIC crap available at WallyWorld. Any suggestions on how to lower the maintenance interval?

If it matters, the fan is on a timer and runs ~12 hours/day.

TIA,
Robert

 

[kenw]

Almost any oil that works will have the same problems or introduce new ones: you'll have to replace that wick first. Try some (real cotton/or wool) felt at the hardware store if it is the thick kind. Look in the door/window inulation dept. and try to match the thickness of the old wicks. Cut to fit, soak it and away you go.

btw, the baffle is called a shroud. Yep, they're rare on the $10 jobs. Sounds like it is definitely worth saving.

 

[Mickey_M]

quote:

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porterdog:


I had to regrease again last night; it's getting old, but this fan really has a nice set of features that I've not seen in the MIC crap available at WallyWorld. Any suggestions on how to lower the maintenance interval?

---

I've been trying Lubegard ATF Protectant, the stuff they sell to make ATF+4 out of Dexron, to oil bronze and oilite bearings.

It's an ester so it's highly polar (sticks to bearings), doesn't evaporate, and so on.

I've been using it on old fan along the lines of what you describe and it works great.


.

 

[TxGreaseMonkey]

porterdog, read my posting on turbine oil. Electric motors should be lubricated with turbine oil, not engine oil. Engine oil absorbs moisture, which creates acids which damage bearings over time. Turbine oils readily separate moisture and water, contain antiwear additives, but no detergents. As kenw stated, you have to replace the wicks. 3-in-One Oil is a mineral turbine oil and its viscosity is around SAE 16 to 18. I prefer synthetic oils, but Amsoil and Mobil turbine oils usually come in 5 gallon containers. Alternatively, you could use Amsoil ISO 46 Compressor Oil (PCIQT), which comes in quart containers. This would equate to a SAE 20 weight oil.

 

[kc8adu]

sounds like my old lau.
the packing in it had become hard as a rock and refused to absorb oil.
the packing is there to hold oil and ensure a constant film on the bearing.
a repack and soak with m1 fixed it.
go ahead and fix it up.you cannot replace it with like quality unless you pay 125.00 or so on ebay for another.
they bring silly money to collectors.a friend auctioned one off and told me what it brought.
i keep old well built stuff and if mainainence is done these thing last forever.my tv and stereo have tubes!

 

[porterdog]

Thanks for the suggestions, y'all. Re: the packing- is it supposed to touch the spinning shaft or does the oil 'soak' through the bearing? This unit is old, and though it *looks* like the packing only ever touched the outside of the bearings I can't be sure of that....

TIA,
Robert

 

[kenw]

I believe it only needs to touch the outside of the bearing. Surface tension and the "porous" bronze bearing wicked it in the rest of the way.

good luck

 

[porterdog]

[caution] Success! [/caution]

I did like you all suggested, replacing the old wicks with new wool felt. *That* was fun; had to beat out the old assembly rivets and replace with pop rivets after stuffing the cavity with felt. Also got some turbine oil like TxGreaseMonkey suggested and it really seems to have done the trick... Hasn't been that long since I did all this so the jury is still out, but I do notice that the blade spins longer now when you cut the power which is definitely a good sign!

Thanks again,
Robert

 

[kenw]

good work! Now just mark on your calendar to add some of that oil once a year, preferrably in the spring before you use it and and after it has sat unused for the winter.

 

[porterdog]

LOL, after the h**l I went through this summer taking it apart and putting it back together ~10 times I can't possibly forget

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