On Friday 24 October 2014 04:24:20 Gregg Eshelman did opine And Gene did reply: > On 10/23/2014 8:59 AM, Gene Heskett wrote: > >> If you want the fan to not fail again, use a drop of silicone oil on > >> its bearings. Silicone brake fluid is ideal for the job. It's > >> essentially silicone oil with a touch of purple dye and possibly > >> some corrosion inhibitors. > >> > >> It has much better heat resistance and will not dry out due to > >> evaporation of VOCs. > > > > That is not something I would recommend Greg, although its not > > anything I have tried either. > > > > The reason I wouldn't try it is, particularly in a sintered bushing > > bearing, silicone has essentially zero surface tension, and will > > allow metal to metal contact, accelerating shaft wear considerably. > > Only if well flooded, and spinning fast enough that those teeny > > bearings could float on the hydrodynamic oil film, could I see where > > it might be a good idea. OTOH, when such a dot4 fluid is analyzed, > > how much of it is actually silicon based. Good question. > > > > Anecdote about cheap dot3/4 stuff. > > Silicone brake fluid is DOT5. I've had no problems using it to lube > sleeve and ball bearing computer fans. In some cases after several > times of having oils like 3-in-1 dry up and the fan seize up, a couple > of drops of DOT5 fixed it permanently. > > Got one on the PC I'm using currently with a dual core AMD Phenom II > 555. The brand new fan didn't last very long before it got noisy. It's > now been in use far longer than that with DOT5 for lube. > > Those fan bearings, while fast spinning, are very lightly loaded.
But generally, the shaft od is so small that hydrodymanic effects will not be seen to any great degree at the leisurely rpms they do. So even a 6krpm cpu fan would be considered slow at the shaft surface. Many shafts are <1/8", one I took apart & reoiled was maybe 1/16". > Silicone brake fluid does not absorb water, unlike the garden variety > DOT3. That's why it's so often used in vehicles that don't get driven > much. > > However, the silicone fluid is somewhat compressible so your brakes may > feel a bit soft or squishy, you won't get the same really firm pedal or > hand lever feel as you do with DOT3. > > You do not want to put DOT5 into a brake system that is not completely > flushed of DOT3 or other fluid. Ideally, all rubber parts of the brake > system should be replaced with new parts before switching to DOT5. Also good to know, but why is it compressible? Even water is considered un-compressible, until you take it down in the mohole... It is compressible enough that the batteries that ran the Trieste, which were off the shelf Sears DieHards, each cell of which had a small weather balloon with a half pint of battery acid at 1.26 sg, poured into it and then snapped over the cells neck. A wire cage fitted over the top of the battery kept the water currents from dislodging the balloons & letting sea water into the battery. One of the pix Jacques Picard brought back was one of the battery racks, balloons visible as they started down, balloons not visible at 37,000 feet down, they were stuffed inside the battery by the pressure. Nearly 18kpsi down there. No braking system can do that. 2.5kpsi in a lock em all up stop maybe. > --- > This email is free from viruses and malware because avast! Antivirus > protection is active. http://www.avast.com > > > ----------------------------------------------------------------------- > ------- _______________________________________________ > Emc-users mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/emc-users Cheers, Gene Heskett -- "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) Genes Web page <http://geneslinuxbox.net:6309/gene> US V Castleman, SCOTUS, Mar 2014 is grounds for Impeaching SCOTUS ------------------------------------------------------------------------------ _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
