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?

Thanks,

MC

On Feb 12, 8:05 pm, "MiamiCuse" wrote:
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?

Thanks,

MC

A zip tool with a tile cutting carbide bit would be my first choice.
You would have to go slow.

JK

"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.

A cheaper alternative to buying a new power tool is a hole cutting
compass - you can get one at THE DEPOT. Use this to cut a circle
through the plaster but it won't go through metal lath. Get plenty of
blades if you have to cut more than one. The lath will chew them up.

Next you can crumble out the circle piece then use wire cutters or
sheet metal sheers to cut out the lath. Be careful when cutting that
stuff with anything - power or hand tool - wear gloves. It will shred
your skin worse than a mean tom cat.

This method is slower, but more deliberate with less chance of injury
and cutting where you don't want to.

wrote in message
...
A cheaper alternative to buying a new power tool is a hole cutting
compass - you can get one at THE DEPOT. Use this to cut a circle
through the plaster but it won't go through metal lath. Get plenty of
blades if you have to cut more than one. The lath will chew them up.

Next you can crumble out the circle piece then use wire cutters or
sheet metal sheers to cut out the lath. Be careful when cutting that
stuff with anything - power or hand tool - wear gloves. It will shred
your skin worse than a mean tom cat.

This method is slower, but more deliberate with less chance of injury
and cutting where you don't want to.

I think the compass will take a power drill right? I think I will try this.
Thanks!

On Wed, 13 Feb 2008 08:17:44 -0500, John Grabowski wrote:

"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.


You need a special rotary drill designed for drywall, like the Dewalt DW660
or Rotozip RZ01-1100. You might try some pawn shops for them also for a
better price.

I found this and it seems to describe my precise requirements.

http://www.holepro.com/?gclid=CMPVpp...FREoFQodTQboZQ

Anyone tried it - any luck?

MC