I got the disc sander going again 

So Amelia is now missing a sander as well!

 I was plagued with intermittent rain all day. 

Moonlighting with the weather bureau...  

you reporting/recording 240mm of rain?

 by using the cork backing gripping the concrete driveway. 

Have you tried/heard_of a hybrid of rubber/cork?

(1.5mm and 3mm)... Don't ask... I'm just telling you about it.

If your first cut is too short... Take the second cut from the longer end... LBD