Repair sandstone sill

[opps]

Hi all

I have about 6m of (painted) sandstone window sills on a bay that need a complete skim.

The sills lean in the wrong direction (rain water runs towards the timber windows).

At some point it looks like someone used a Jetcem type product to create a wedge skim (20m to 0mm). Unfortunately it had blown and came off pretty easily.

What sand/cement options would you recommend to rebuild the slope?

If I use Jetcem again how do I ensure that it doesn't crack again. Will a slurry coat and small holes drilled into the sill help?

 

[vinn]

Photo's would help. But first clean off all jetcem or whatever.
I've used a 300mm stone blade in an angle grinder to give in-place sills the correct "slope" - just enough to shed rain.