Drilling a hole in Lava Rock??

My sister in law bought a bulldog made out of lava rock that she wants to put on her husbands grave. She wants to fasten a 1/2" rod about 8" long to the bottom of the dog and push in it into the ground, hoping to deter thieves from taking it off. She was going to use some kind of landscape adhesive to fasten the rod onto dogs butt to hold it in the ground, but the person at the hardware store told her since the end of the rod was curved and the dogs butt was flat, it wouldn't hold very well. She has asked me to come up with a way to fasten the rod to the dogs butt. Can I drill lava rock without breaking it?? My thought was to drill a hole and epoxy the rod in and then push it into the ground to hold it in place. Any better ideas out there?? Personally, I think someone will carry it off soon after it is placed there. But, he is buried in the National Cemetary at the Rock Island Arsenal and they gave her the OK to put the dog on the grave, so she is bound and determined to put it there. Any help appreciated, Chris

From what I've seen lava varies a great deal in consistancy. A masonary drill bit would do it however might cause it to crumble depending on the lava. I believe I would cut as large a piece of ground rated pressure treated wood as I could and make a stake out of it and drive it into the ground. Then glue the lava to it with a polyurethane glue such as Gorilla glue.

Maybe a small slab of cement could be poured there and then set the lava bulldog in the cement. Just thinking out loud here.

I have seen it drilled with a diamond drill bit with coolant on the drill. The bad news is those drill bits are very high prices.

How about a twist on Wile's idea.

Pour a small concrete pad with a rod welded into a tee shape in the concrete. This way the rod is inside the top of the rod is firmly anchored into the concrete. Then after the concrete is cured use masonry adhesive to attach the lava rock bulldog to the concrete pad.

This would make the entire thing pretty heavy. This should discourage most thieves. It also would look like a poured base for the bulldog.

Hello super99,

I think drilling is not the way to go. How about a dremmel tool with a fine bur bit? You can try it on a safe/tick side first. It may go fast enough to prevent splinters,

Guido.

Couple thoughts....

You dont need to drill 8 inches, half that would be more than enough. Using epoxy is the correct product to use, I recommend Bonstone, they are not too far from you in Mukwonago, WI. Call them, they can have stuff to you next day if needed. Bell out the hole so its wider at the bottom, that prevents pull-out.

You should use a diamond drill bit. A carbide bit [i:e3b8b88a84]may[/i:e3b8b88a84] work but if it catches in the hole, it may break something and if that something is the bulldog... well thats not good. Same with using a tile bit, they are cheap and will work to drill hard stones, given enough time and water, but if it catches in the lava, it could be bad juju for Mr. Bulldog. I cant find a diamond bit to recommend so I would use a diamond burr, the only problem is the shank on those are so short. You will have to weld on an extension, it sucks, I know but it works and since the burrs are so cheap, if you mess up, its no big deal. Oh, and dont use a hammer drill. They are fast and easy but can also break the stone so in a high risk operation like this, dont use one.

When you drill, 3 rules: high speed, low pressure and cool bit. Drill it as fast as your drill press goes. Very low pressure, this is not a race. It preserves your bit and helps keep from cracking the stone. Lots of water keeps the bit cool, if it gets hot the diamonds go bye bye. You also need to keep the stone cool so it dont thermal fracture. Last, if your diamonds do away, you could end up melting the bit, causing it to mushroom over. When that happens, you cant get the bit out, the worst of all juju.

Adding weight would help deter theft. Have you considered mounting it to a piece of granite to match the headstone? Most headstones have a base stone to prevent mowing damage, maybe put the dog on one of those? If you do that, you can attach the dog to the granite base and then the granite base gets set in concrete at the grave. In order to take the dog, they gotta take everything, dog, base and concrete. Thats hundreds of pounds, a common thief not only wont but cant take that. Thats the way I would go but if the grave stone is a traditional military stone, it may not match (but you could still set the dog in concrete).

Its not a hard job, an hour should do it. Setup will take up more time and then a couple days waiting for the epoxy to dry.

A half inch rod stuck in the ground eight inches can be pulled out with one hand. Try using stone epoxy. Found a site that tells about it. www.defusco.com. Look on the left side of page for Glues and epoxy.

Lots of good ideas here about how to poke a rod up a bulldog's butt. As far as securing it to the ground, may I suggest that use a mobile home tie-down as your rod---cut off the eye and put the auger end into the ground. Drill a pilot hole with a post-hole digger.

One possible solution is to weld a flat plate to the rod , shape the plate to the base of the dog , this will give a huge area to use glue on . Urethane sealant / adhesive works very well in damp environments on porous stone . The other end of the rod needs a heavy weight as wide and as deep as it is respectable to go .

Another way to make a hole in rock is with a sandblaster. Use a piece of rubber, like innertube, with a round hole in it as a stencil.