Linear Scales

Hi folks

I have a wee problem with my lathe - After standing idle for the last few
months, I powered it up and found I have some oil on the glass scale (Z axis).
It is something that has happened before. I had removed it and cleaned
everything down with alcohol, and it worked fine. I am going to have to strip
half the carriage off to get to it again - Question is - Is there anything I
can do to prevent it happening again ?

Regards, Paul.