Never, NEVER, use WD40. It disintegrates plastic obliteratingly fast. CR&R
Silicon spray is my recommendation.

--- In caltechrubiks@yahoogroups.com, Tyson Mao <tyson.mao@...> wrote:
>
> I can't help you too much with your second question as I have never
> purchased only a core.  (Though I could use one myself.)
>
> As for lubing a cube, there are differing schools of thought, but most
> people use a silicon based spray.  Generally, the cube is not flawless
> at first while the silicone is still wet.  Generally, you want to wait
> for it to dry before you put it back together.
>
> -Tyson
>
> On Thu, May 7, 2009 at 4:35 PM, b47lue <b47lue@...> wrote:
> >
> >
> > I am new to the cube world and would like some advice on how best to
> > maintain a cube.  I have seen differing opinions on You Tube about how to
> > lube the inner parts of the cube.  I was attempting to clean up an older
> > cube and used WD40.  After about 30 minutes of it not getting any better, I
> > took it apart and used alcohol to clean all the parts.  I re-lubed
> > everything with silicon but when I was putting it back together, the core
> > just fell apart.  The plastic core just crumbled away.  So I have two
> > questions: 1) what should be used to lube a cube and 2) where can I purchase
> > a 3x3 Rubik's core?  I saw one core for sale on Cubes4You.com but I don't
> > know if it is the correct type.  It doesn't look like the one that fell
> > apart on me.  Thanks for your help/advice!
> >
>