On Jan 10, 1:24 am, "Dave" wrote:
I bought one of these little rascals that help you to do mitres in the stuffhttp://tinyurl.com/yzhmpor(link goes to Axminster tools) but what's the
best implement to actually cut polystyrene coving with? Wood saw? Hacksaw?
Bread knife? Something else?

I (and the professionals next door) use an old back saw in a mitre
box.
The polystyrene is outdoors so I don't know or care whether it's fire
retarded.