"zek" wrote in message
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On May 28, 6:31 pm, "RBM" wrote:
"zek" wrote in message

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On May 28, 6:13 pm, "RBM" wrote:

"zek" wrote in message

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my house has walls that are very thick and heavy. Cutting electrical
outlet holes and ceiling holes is very difficult. Using a saws all
with a big tooth demolition blade, I get maybe 20 inches before the
blade is flat. Ceramic blades are much worse. Am I doing it. Right?
I find finer tooth blades are worse.

Greg

What is the material that you're cutting? Other than outlet boxes, what
are
you cutting on the ceiling?

I have cut ceiling recessed lights and an attic entrance. The round
holes need a smaller blade which goes bad fast, there is no lath or
metal or wood. I'll see if I have a piece to take a photo.

Greg

I think what you have, is rock lath plaster, it's like a layer of 1/2"
sheetrock with holes in it, that's plastered over. The plaster keys into
the
holes. It winds up about an inch thick, and is often very hard. I usually
cut outlet holes in that with a hand keyhole saw. It's work, but you're
getting a clean rectangle with no big chips. For the recessed lights,
Lenox
makes carbide hole saws that work great. The only down side is the dust. I
cut a basketball in half, and drill a hole in the center of one half,
slide
it over the hole saw, which helps to trap the dust and plaster particles.

Picture".........

http://zekfrivolous.com/wall/wall.JPG

Greg

Looks like rock lath, but I've never seen the plaster coat that thick. It
looks more like cement than plaster. OK, so you live in a bunker. If you're
near tornado alley, that's a good thing. Look at the bright side, when
you're done with this project, you'll have the biggest biceps in town.