Drilling or cutting a hole in thick slate

[webbie]

I need to drill or cut a decent size hole in a piece of slate which is 2 foot by 2 ft, and about 1 1/4" thick. The hole can be as small as an inch or as large as 6 inches square (it gets covered)....

I have nightmares of taking a hammer drill to this thing and having it crack. It's pretty solid, but still....

One thought is to just use a masonry blade on my circ saw and lower it slowly into it. But this might be very slow.

Am I being too careful - should I just use a small hammer drill and perhaps drill 3 or 4 small holes next to each other to make a larger hole?

 

[JohnnyBravo]

slate cuts like butter with a masonary blade. i have even used a hole saw with some water. 1 1/4 may burn out a bi-metal hole saw. you can get a cheap bit for drilling wall tile. it should work. dont take a hammer to it.

 

[MrGriz]

What about a tile cutting bit and a roto zip? I'm not sure if it will get the 1 1/2 inch depth, but those things will cut through just about anything. I agree that I wouldn't take a hammer drill to it.

 

[JohnnyBravo]

roto zip should work. it may take a few passes, stepping a bit deeper each time.

 

[Hogwildz]

at 1-1/4" thick, I doubt even a hammer drill would break that thing. Unless you are right at the edge. You could even try a masonry bit with a normal drill or normal drill setting on your hammer drill. I have some 1/2 thick slates here. I can try and drill through one with my hammer drill and report back to you? Is it true slate or blue stone? I cut my slates for the heart with a 4" angle grinder with a masonry blade. Cut like butter. And you could cut a smaller hole than a circular saw would cut.

 

[kjklosek]

A diamond hole saw is what you want.

Nice clean hole, safe and easy to do without worry.

http://www.tiletool.net/hole_saw_diamond.asp

J.P.

 

[kenkathy]

I just drilled 16 holes in a piece of billiard slate last weekend. I had similar concerns myself before starting the project of ruining 600 buck worth of slate. I used 2 masonry bits. I made a small pilot hole and then used a 1" bit to drill my final hole. Don't use the hammer drill setting. Drills like butter.

 

[Fire_Eye]

Get a simple 3/16 or 1/4 masonry bit (cost $3) and drill a series of holes. First draw the size opening you intend to make in the slab of slate in marker front side and back side. Then drill out the perimeter of your mark with the drill bit and grout the rest. If the slate is really soft and you are set on making a perfect hole I would try cutting trough with the wood-hole-saw and water like Johny mentioned. The masonry hole-saws are expensive! I have 8 years of commercial tile installing experience backing up my suggestion.

 

[Gooserider]

Interesting topic, but seemed a bit distant from the hearth, so I moved it to the DIY room - seems to me like a better fit.

Gooserider

 

[webbie]

Oh yeah, it's done. It did turn out the stuff is very soft - a regular carbide tipped masonry bit (1/2") went through like butter. I drilled about 6 holes and they connected.....

Hah, the only way this is hearth related is that I am working on a light for my yard that consists of a masonry base which looks like a chimney, with a slate cap and then an extendaflue chimney pot on top, with light inside. Soon come......

My wife likes to say it is a $200,000 light. She might be close.

 

[Gooserider]

Oh yeah, it's done. It did turn out the stuff is very soft - a regular carbide tipped masonry bit (1/2") went through like butter. I drilled about 6 holes and they connected.....

Hah, the only way this is hearth related is that I am working on a light for my yard that consists of a masonry base which looks like a chimney, with a slate cap and then an extendaflue chimney pot on top, with light inside. Soon come......

My wife likes to say it is a $200,000 light. She might be close.

Sounds like fun... I'm actually finishing up a minor project that I had to drill a bunch of little holes in a 1/4" slate tile. I didn't put in my solution since I was making holes about 1/8" diameter (can just get a #6 wood screw through them)

I tried several different bits, and found most either didn't want to work, or caused the test scraps of slate to break. This included a carbide glass drilling bit, and some diamond dremel bits. I ended up using a carbide micro-bit that was part of a set of 50 assorted that I purchased from HF a few years ago - I put a few drops of water on the slate and drilled through it like butter. I didn't think to try a masonry bit, but this worked, so no complaints.

The inspector from the FD says we had to have house numbers on the house, not just the mailbox at the end of the drive. The GF says she wants to have an arrow pointing around to the front door, since as you may remember from the Hearth Party, the garage faces on the driveway, and it isn't real clear where the entrance is. She couldn't find anything she liked at the local shops or online, so I suggested getting a sign - Web searching looked like the minimum for what we wanted would have been over $80, probably twice that for something nice... :grrr: No way were we going to pay that.

Instead we went the DIY route - I took a leftover 12" x 12" slate tile from the hearth extension project, and drilled a small hole in each corner. Went into the word processor and played with font sizes until I found that 175 point works out to the right size to print out and make a stencil, did some similar stuff with a paint program to make an arrow that says "Enter" on it... Printed out stencils, cut out, and painted on the slate with "Patio Paint" - billed as exterior grade paint for stone, flower pots, etc. - two bottles at ~2.50 each... Result will be a nice hand painted house number sign w/ about 8" high numbers and an arrow for about $5.00 w/ plenty of paint left over. :coolgrin:

Gooserider

 

[JohnnyBravo]

sounds cool the pizza delivery guy will also like the new sign.