"MiamiCuse" wrote in message
...
I posted a query last week about cutting a straight line along plastered
wall with gypsum lath with a concrete block wall about 3/8" behind it and
PT furring strips in between, and it was chewing up the blade and someone
suggested using a skilsaw or jigsaw. I have not tried it yet but a similar
problem is happening on the ceiling where I need to cut circular holes for
recessed cans.

The ceiling is also plastered over gypsum lath so overall thickness is
about 5/8". Will a normal hole saw work or I need special diamond blade
hole saw?



Special carbide hole saws are made for recessed lights. They are expensive
but work great on plaster and lathe. Be sure to get the correct size. I
tried my Dremel Rotary Advantage once on some recessed lights. The first
hole or two didn't come out too well even though I was using the circle
cutter attachment. By the fourth hole they were looking great until the
tool froze up from all of the fine dust getting inside of it. I had to
completely dismantle the Dremel to get rid of all of the dust. I haven't
used it since.