EEVblog Electronics Community Forum
General => General Technical Chat => Topic started by: WorldPowerLabs on November 29, 2012, 08:12:26 pm
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Hello EEvbees,
I own an old HP 240D audio oscillator. While the unit is in excellent shape electronically, the old grease on the gears and other moving parts within has oxidized and become gummy.
I have received two different (and conflicting) suggestions from Agilent -- one with the disclaimer that the greases referenced in the service literature are no longer relevant and that his suggestions are not official Agilent recommendations, per se.
One recommendation was to use dielectric grease (silicone). The other was white lithium grease. Naturally, I'll do my best to clean out the old gunk before replacing with anything new.
Does anyone have a favorite grease for this sort of application? I've used white lithium before, and it always seems to separate into the oil and the soap base after a while.
Thanks!
-Ben
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IMO steer clear of dielectric grease It has its place but general lubrication is not one of them. Silicone is next to impossible to remove and it also migrates on its own to places you dont want it to. Under certain conditions it can form silicon carbide a very effective abrasive.
This thread (https://www.eevblog.com/forum/product-reviews-photos-and-discussion/question-dmm-grease/msg143815/#msg143815) covers its quirks fairly well.
Tri-flow synthetic grease is pretty good stuff for general mechanical lube (not for contacts). Most test instrument lubrication requirements are very low speed and load and is not that demanding anyhow.
I like Caig Deoxit gold G100L for contact lubrication and Caig Deoxit D100L for contact cleaning.
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Robrenz, good info -- thank you. I don't particularly like silicone greases because of their tendency to migrate, as you've noted. I'll probably try the Tri-flow synthetic grease. These parts needing lubrication are indeed purely mechanical (no contacts).
I use Deoxit (red, in various concentrations) for contact cleaning and Deoxit (gold, 100%) for preservation and lubrication, too. I particularly like to use the latter on switches where the contacts are pads on a PCB and metal wipers slide across them, as in many multimeters.
Thanks again...
-Ben