Re: Can you give me some guidance?

[shields@tembel.org (Michael Shields)]

> I don't know what it's locking properties are if any, but you need the
> lubrication properties to prevent damage to the threads which are pretty
> fine, and you want to take it apart again someday.

I wouldn't think a 12.9 hardness bolt would be damaged very easily.
I would like to have the Loctite there, not as the primary means of
holding it on, but just as an extra safety net.

> I would be willing to bet that the very high torque that is specified
> was done so that a locking compound would not be necessary.  Locking
> compounds will fail after time and stress especially on large fasteners,
> like on a reused front wheel axle nut BTDT.

Not arguing that...

> > Does it really contain Teflon?  If so the Teflon's not doing anything
> > useful any more than it does in Slick 50...
> 
> Yes.  The Teflon is a solid lubricant (like graphite) that won't evaporate
> or flow away with time.  Once that bolt is in there the Teflon is not going
> to go anywhere.  No constantly moving or rubbing parts like Slick 50 has
> to deal with.  It is useful when the parts are moved during installation
> and removal.

I did some brief research into this.  My understanding was that the reason
Slick 50 isn't useful is that Teflon needs to be applied at bare metal at
high temperatures to form a non-stick surface (like a skillet).  Dupont
has been quoted as saying that PTFE has no value as an oil additive.
But people know the Teflon name so it's used for its marketing power.

However, I trust Loctite, so if they're making a Teflon product it's
probably because the Teflon does something.  So I looked on www.dupont.com
and one of the products they have are 100% Teflon bicycle drivetrain
lubricants.  So maybe it can be a dry lubricant.

> Is there a mechanical or fastener type on the list who could elaborate?

Would be nice.  Why does Audi recommend this strange compound instead
of regular antiseize?  Or Loctite?

> > > My bolt uses a 1 1/16 " socket.
> > 
> > Whatcha doing with these 'Murican sockets on an Audi?
> 
> I measured the bolt hex head and bought the closest metric sockets.  A 27mm
> is too big and a 26mm is too small.  The rear wheel bearing nut (front
> wheel drive only) is english as are the few hex head sheet metal screws
> that are on my car.

I don't know why... a 27 mm socket fit mine.
-- 
Shields.
[happy to use my limited knowledge of materials science
 to embarrass myself in public]