Tough live rock - lost drill bits

[DmitryB]

So I was drilling a live rock to put in frag plugs - and lost pieces of two bits in there. A DeWalt and an Irwin. Question is: are these two broken off tips are going to cause problems when left in saltwater? Or are they ok? I've tried getting them out, but this rock is rock hard!

 

[Fish Fan]

I probably wouldn't use that piece of rock, you don't want metals in your tank

You can glue frags to rocks, or purchase rocks that hav already been drilled to accept plugs. If you want to drill your own, you'd want a masonry drill bit (for drilling through concrete and block).

 

[DmitryB]

I probably wouldn't use that piece of rock, you don't want metals in your tank

You can glue frags to rocks, or purchase rocks that hav already been drilled to accept plugs. If you want to drill your own, you'd want a masonry drill bit (for drilling through concrete and block).

Gonna order masonry bits. Hope I can rescue this rock, it's a nice long flat one that I was going to put two Zoas on!

 

[ColoradoReeferman]

I know this isn't drilling, but I bought a 50 pack of small superglue tubes and open it up and squirt the whole tube. So far it's working well, but I've only been back in the game for 1 year sooo..

 

[KrisReef]

I would toss that granite and get aragonite rocks.

Can you post an image of the rock and bits. There must be a way to back these out?

 

[DmitryB]

Here are the pics of this piece of granite. I actually drilled a hole on one side ok, but the other side is made of steel or something.

The broken DeWalt bit isn't this exact bit (I threw that one out), but it's from the same set.

 

[overhead]

You are breaking off more drill bits in that rock than I do drilling steel with cheap Dewalt drill bits! There are drill bits made for drilling rock, I would get those if you are having issues. Personally, I would not add any rock to my tank that contained parts of a metal drill bit. I don't think I would use a step drill bit to drill into rock.

 

[KrisReef]

Yeah, a concrete drill bit might be a better tool? Twist drills tend to get caught up by the uneven deposition of coral skeleton. From AI

For drilling into concrete, you need a masonry drill bit featuring a hardened carbide tip. Hammer drill is also a plus!

 

[UncommonSense]

As stated above; carbide tipped rotor hammer bits are the way!

You do specifically want a beefy hammer drill, or true rotor hammer to really drill holes over 1/4”-3/8”, though… standard handheld drills are sold as hammer drills, but have a laughably small amount of hammer force… you’ll likely damage the bit via overheating before drilling a 1/2” hole via carbide bit with a cordless drill!

(this is to say, rock is drilled primarily via percussive force; pulverizing the rock the carbide smacks against… the drill flutes are simply there to evacuate the pulverized rock dust, and the carbide tips are actually not particularly sharp!)

 

[DmitryB]

I ordered a few concrete bits. I am not sure I want to invest in a hammer drill because I won't be using it that much! But hopefully the concrete bits can a) drill through and b) push out the pieces wedged inside.

Incidentally I tried to drill through a piece of LifeRock for a frag and the drill wouldn't even make a dent. Whatever that thing is made out of, it's ain't porous!

 

[UncommonSense]

I am not sure I want to invest in a hammer drill because I won't be using it that much!

If you’re using a standard battery operated handheld drill, it’s likely to have a hammer setting built-in! Specifically, a ring near the drill chuck you can spin to select different drill settings!

It would look like this:

This is the aforementioned hammer drill setting for a typical drill, not to be confused with a dedicated rotor hammer!

 

[DmitryB]

I got a DeWalt 20v brushless. It doesn't have a hammer. It's got the screw and then numbers up to 15. But no hammer.

 

[Fish Fan]

I got a DeWalt 20v brushless. It doesn't have a hammer. It's got the screw and then numbers up to 15. But no hammer.

A hammer drill is indeed the right tool to drill concrete, rocks, and block, and I do appreciate high-quality tools, but this is a case of go to your local Harbor Freight and get a set of masonry bits like these for 6 bucks (consider these bits disposable), and just go at it with your regular drill like a Neanderthal. Oh yeah, wear some eye goggles

https://www.harborfreight.com/masonry-drill-bit-set-5-piece-63074.html

 

[overhead]

A hammer drill is indeed the right tool to drill concrete, rocks, and block, and I do appreciate high-quality tools, but this is a case of go to your local Harbor Freight and get a set of masonry bits like these for 6 bucks (consider these bits disposable), and just go at it with your regular drill like a Neanderthal. Oh yeah, wear some eye goggles

https://www.harborfreight.com/masonry-drill-bit-set-5-piece-63074.html

I usually just use safety squints

 

[DmitryB]

Well, got the concrete bits today. And guess what? Left a tip of one of them in the rock. So now that was THREE (3!) bit tips in the rock. It was time to say goodbye to this boulder made of who the heck knows what!

 

[slingfox]

Well, got the concrete bits today. And guess what? Left a tip of one of them in the rock. So now that was THREE (3!) bit tips in the rock. It was time to say goodbye to this boulder made of who the heck knows what!

I also have a standard 20V Dewalt driver drill. I tried a bunch of different types of bits and I was not able to effectively drill into Marco Rock. I made 1-2 holes but it took forever. If you really want to drill the rock you can rent a hammer drill.
That will get the job done much more effectively.

 

[fish_collector]

A Hilti demolition hammer might work

I've never had good experience drilling holes in live rock, I've broken perfectly good pieces of rock trying to make a frag plug fit. It's just too brittle. I've often wondered if a small diamond hole saw would have been better.

I have never liked to insert frag plugs into holes in rock, the plug sticks up too high and you will always see it even after a coral encrusts it. If you want something temporary to hold frags for a while you can buy ceramic rocks with holes already in them.

 

[UncommonSense]

If you really want to drill the rock you can rent a hammer drill.
That will get the job done much more effectively.

A word of caution to anyone using a rotary hammer on calcium rock would be that there is definitely a chance of the rock splitting or shattering during a drilling attempt, particularly the more porous/fragile stuff!

I’d recommend a SDS+ vs. a SDS max unit (the smaller one), and using a minimum of tool feed pressure/avoiding the larger 3/4”+ bits!

A Hilti demolition hammer might work

This is precisely what I used for my rockwork; drilling 1/2” holes in every rock to slide them down heat-bent 3/8” acrylic dowel rods like a rock kebab!

 

[DmitryB]

I've basically given up. That particular rock, which I liked, is gone because there's all this metal in it now! It was a heavy piece, so not very porous. I did order Marco's frag rocks which may be good, we shall see. And I ordered a tool to crack the mounting stick off the plug, which will make drilling unnecessary.

It seems nobody really likes having their frags on plugs, but everybody sends frags on these things. Can't they find some other way to do this so we are all collectively not dealing with this?!

I'm hoping the Zoas will cover the plug, not sure yet how the other corals will do. Does coralline eventually cover them?

 

[DmitryB]

I also have a standard 20V Dewalt driver drill. I tried a bunch of different types of bits and I was not able to effectively drill into Marco Rock. I made 1-2 holes but it took forever. If you really want to drill the rock you can rent a hammer drill.
That will get the job done much more effectively.

I tried drilling LifeRock and that thing needs one of these.