[Shop-talk] 1" hole through cinder block ?

[Randall]

I'm working on plumbing (and wiring) a new air compressor for my shop.
Turns out the 3/4" air line needs to run through some decorative cinder
block.

Any suggestions for how to cut an approximately 1.25" diameter hole through
the block, with the least risk of breaking the whole thing in half ?  

I see HF has spade-type masonry bits to 1", with turned down shanks; but I'm
not sure how to enlarge the resulting hole.  

Any suggestions ?  I've got an ordinary 1/2" drill motor; really don't want
to have to buy a hammer-drill for just this one project.  Also an air
chisel, but I'm worried breaking the block with it.

Randall