Making circular holes in wood lath and plaster ceiling

[wwhitney]

Hello,

In perusing past threads, I've seen carbide grit hole saws recommended for making circular holes in a wood lath and plaster ceiling. I see that these come in two types: either a continuous rim, or one with teeth. Which style works better to cut horse hair plaster with minimal vibration? Will either style work to cut through both the plaster and the wood lath, or is it just a better idea to switch to a regular bimetal hole saw for cutting the lath?

Thanks, Wayne

 

[Sierrasparky]

Hello,

In perusing past threads, I've seen carbide grit hole saws recommended for making circular holes in a wood lath and plaster ceiling. I see that these come in two types: either a continuous rim, or one with teeth. Which style works better to cut horse hair plaster with minimal vibration? Will either style work to cut through both the plaster and the wood lath, or is it just a better idea to switch to a regular bimetal hole saw for cutting the lath?

Thanks, Wayne

Grit carbide fine for cutting the plaster. however you need to switch to cut the wood.
Carbide teeth should work for both but may not be fine tooth to get through the wood smoothly.

 

[wwhitney]

Yeah, I was wondering if something like this could do an adequate job of cutting the wood lath, to avoid having to switch hole saws.

 

[tkb]

Yeah, I was wondering if something like this could do an adequate job of cutting the wood lath, to avoid having to switch hole saws.

I would give it a try, but have a bi-metal hole saw with me in case it doesn't work too good on the lath.

 

[kwired]

If you are going to switch to a bimetal hole saw to cut through the lath, you will need to knock the plaster "keys" out from between the lath, or else you take the edge off the cutting teeth in no time.

 

[JFletcher]

If you are going to switch to a bimetal hole saw to cut through the lath, you will need to knock the plaster "keys" out from between the lath, or else you take the edge off the cutting teeth in no time.

Yep.

Drill it slowly. Busting a huge hunk of plaster coat is going to be an expensive fix. and any plaster grit left over will wear out a bi-metal bit in a flash.

I would go so far as to check the integrity of the plaster before drilling. You do not want to be responsible for a dinner-plate sized chunk of plaster separating from previous damage where you are drilling.

I would not cut wood with a carbide/masonry bit, no more than I'd try to run a concrete hammer drill bit thru a 2x4. Metals/ceramic/porcelain/glass doesnt have a grain, and doesnt give. Wood does. my two bits: use two bits.

 

[keith gigabyte]

Holes

Holes

We do a lot and I mean a lot of plaster lathe holes. Best way is first make sure plaster is secure...it often separates from the lathe boards. Then use carbide. We use the sectional ones rather than continuous edge. Easier on the arm. But definitely switch to bimetal for lathe boards. Make sure to clear plaster or u will ruin bi metal saw. Most holes take about 5 minutes. Go gingerly and slow. Very easy to get a blow out and plaster will leave a dent in your pocketbook.