[HAM] CV - Starter motor not engaging TG - follow up

[David Anderson]

The people who make sintered bronze bearings state that they should  
be lubricated with a fairly pure oil--no additives (they recommend  
"turbine oil"), and the people who manufacture WD-40 state that their  
product should not be used on such bearings. WD-40 is for things like  
steel tools where it's good to leave behind a protective layer to  
prevent rust. Think of porous bronze bearings as a metal sponge. If  
you clog up the tiny holes in it, it doesn't work like it's supposed to.

If you look at the MSDS for WD-40, the main ingredient is "aliphatic  
petroleum distillates," i.e., solvents, but it also contains stuff  
that isn't needed for cleaning bearings and may be detrimental.

What makes intuitive sense to me is what Steve Leigh describes: You  
need a pure solvent to dissolve gum and varnish, and it stands to  
reason that if a solvent is holding other chemicals in solution, it  
won't be as effective as a pure solvent. Once the gunk is gone, you  
don't want to leave other gunk behind. Then, you want an oil that  
contains as little of whatever eventually becomes gum and varnish as  
possible.

I recently soaked a poorly-performing Leslie horn bearing (also  
porous bronze) in hardware store alcohol and then blew it out with  
compressed air. The first blast of air blew all kinds of brownish  
crap out of the bearing, and I repeated the process till it blew  
clear. After being re-oiled, it works perfectly.

And I apologize, Scott, if I came off as snotty. It's the end of the  
semester, and I'm in paper-grading hell. My interest is solely in the  
longevity of these instruments.

David Anderson

P.S. I hate the smell of WD-40 ;-)

On Apr 20, 2007, at 10:44 PM, OF wrote:

> At 04:58 PM 4/20/2007, David Anderson wrote:
>
>> I go by science, not faith.
>
> Yeah, so do I. Science means that if you do the same experiment  
> repeatedly
> over time under the same conditions, and get the same results, the  
> thing is
> proven, for now. That goes for, as John Lynch told you, using WD-40 on
> Hammond tone generators, notwithstanding Steve's educated  
> speculation that
> they must be getting gummed-up. When that starts happening, I will  
> change
> my mind. And thanks for the snotty mischaracterization of my  
> beliefs. Ypou
> don't want to do that, trust me.