Cutting rockwork in tank.

[kilnakorr]

I have my rockwork build using cyano glue and sand. Very strong bond it seems.
I would love to cut the top of the rockwork, but not sure the best approach.
Small hacksaw, try crushing pieces with a pair of big 'pliars' (no idea what these are called in English).
The piece where I'd like to cut the rockwork, has a decent cave, so not really a solid piece of rock. Any ideas and tips are appreciated!

 

[Troylee]

Bolt cutters would do the trick… or a hack saw but that’s time consuming lol..

 

[Harpo]

I believe that BRS calls them bone cutters but I suspect they are too small for your application

 

[shakacuz]

if you can't remove the rock from the tank, a hack saw may be your only help unless you use the "bone cutters" we typically use to frag coral and chip away at the rock little by little. i would say a chisel and hammer....but the force needed + the glass/vibration is the concerning aspect of that suggestion.

 

[kilnakorr]

Bolt cutters would do the trick… or a hack saw but that’s time consuming lol..

Bolt cutter would be way to big to get a decent angle for the cut.

 

[kilnakorr]

I believe that BRS calls them bone cutters but I suspect they are too small for your application

if you can't remove the rock from the tank, a hack saw may be your only help unless you use the "bone cutters" we typically use to frag coral and chip away at the rock little by little. i would say a chisel and hammer....but the force needed + the glass/vibration is the concerning aspect of that suggestion.

That might work.
I do have a pair of the big bone cutters.
Might be able to cut/break the rock around the edge as it is pretty much like a tube.

 

[JayM]

Is there room to insert some sort of prybar into the "cave" and twist the rock off?

 

[907_Reefer]

How wide is it where you need to cut?

Can you pull out the section with this piece (snap it out of the glue), quick hammer/sledge job and toss it back in?

 

[kilnakorr]

Is there room to insert some sort of prybar into the "cave" and twist the rock off?

Maybe. Mostly scared of the presdure it might do downwards. Could potentially crack the bottom of the tank.

 

[kilnakorr]

How wide is it where you need to cut?

Can you pull out the section with this piece (snap it out of the glue), quick hammer/sledge job and toss it back in?

Not really.
Picture of rockwork before it when into the tank.

 

[KrisReef]

Not gonna be easy, but a coarse hacksaw blade with a duck tape handle (like we use in jail) to undercut the area where you want to remove, and then a big screwdriver to wedge in the cut, or a hammer to tap on the opposite side of the cut might get the piece to give way where you are hoping. Problem with a hammer is that you have to be careful not to aim force towards the tank through the rock and hitting coral rock often causes it to break in the unscene weak points that will be obvious after the hitting brings results.

I chisel liverock outside of the tank and it can be difficult to apply force in the area you want to create a crack and separation.

So set up a camera on the tank if you decide to do this underwater. Lots of people will want to watch if the tank gives way before the rock does?

 

[CBonito]

A wide and sharp chisel and a whack from a hammer....like very carefully.
I've already done that in my acrylic tank to break a rock that was too big.

Make sure you wash off your chisel and dry it, so you can use it again.

 

[kilnakorr]

Not gonna be easy, but a coarse hacksaw blade with a duck tape handle (like we use in jail) to undercut the area where you want to remove, and then a big screwdriver to wedge in the cut, or a hammer to tap on the opposite side of the cut might get the piece to give way where you are hoping. Problem with a hammer is that you have to be careful not to aim force towards the tank through the rock and hitting coral rock often causes it to break in the unscene weak points that will be obvious after the hitting brings results.

I chisel liverock outside of the tank and it can be difficult to apply force in the area you want to create a crack and separation.

So set up a camera on the tank if you decide to do this underwater. Lots of people will want to watch if the tank gives way before the rock does?

The hammer/force thing is already getting me nervous although I might get my 15 minutes of fame on tiktok in case I screw up.
I think I (might) try the bone cutters, to see if crushing the rock is even possible, and then plan B will be the hacksaw.

 

[KrisReef]

The hammer/force thing is already getting me nervous although I might get my 15 minutes of fame on tiktok in case I screw up.
I think I (might) try the bone cutters, to see if crushing the rock is even possible, and then plan B will be the hacksaw.

Taking bites can work but it will depend on how solid or porous that rock is. I have used needlenose pliers, vice grips, and similar tools to crush through softer live rock but as mentioned earlier the rock sometimes breaks in the wrong location when applying force where you think the rock will give. Good luck. We do want pictures to document the success of the operation.

Too success!

 

[rennjidk]

Please don't attempt to chisel that away inside of your tank. No offense to anyone, but that just seems unnecessarily disastrous. Removing the piece from the tank will obviously be the best option, the corals should be fine out of water for a few mins. If you're really dead set on not removing it, here are a couple options:

If you have a Dremel, pick up one of those long flexible extensions like the nail salons use. You should be able to use a stainless steel blade to either cut it off, or at the very least, score the rock really well from all sides and just snap it off with your hand. This would be my go to, but I already own both.

Grab a 6" mini hacksaw at harbor freight for like $3. It will be much easier to control than working with a full length blade wrapped in tape, and much less likely to end up at the ER.

You could use a wire saw. They sell them at Walmart in the camping section for like $2. Just wrap it around and start pulling.

Youll probably need an extra set of hands to hold the rockwork in place unless you go the Dremel route. Good luck!

 

[kilnakorr]

Please don't attempt to chisel that away inside of your tank. No offense to anyone, but that just seems unnecessarily disastrous. Removing the piece from the tank will obviously be the best option, the corals should be fine out of water for a few mins. If you're really dead set on not removing it, here are a couple options:

If you have a Dremel, pick up one of those long flexible extensions like the nail salons use. You should be able to use a stainless steel blade to either cut it off, or at the very least, score the rock really well from all sides and just snap it off with your hand. This would be my go to, but I already own both.

Grab a 6" mini hacksaw at harbor freight for like $3. It will be much easier to control than working with a full length blade wrapped in tape, and much less likely to end up at the ER.

You could use a wire saw. They sell them at Walmart in the camping section for like $2. Just wrap it around and start pulling.

Youll probably need an extra set of hands to hold the rockwork in place unless you go the Dremel route. Good luck!

No way og getting that huge rockwork out of the tank. If only.
I'm going to give it some thinking time, before I make the attempt.

 

[Dburr1014]

Not gonna be easy, but a coarse hacksaw blade with a duck tape handle (like we use in jail) to undercut the area where you want to remove, and then a big screwdriver to wedge in the cut, or a hammer to tap on the opposite side of the cut might get the piece to give way where you are hoping. Problem with a hammer is that you have to be careful not to aim force towards the tank through the rock and hitting coral rock often causes it to break in the unscene weak points that will be obvious after the hitting brings results.

I chisel liverock outside of the tank and it can be difficult to apply force in the area you want to create a crack and separation.

So set up a camera on the tank if you decide to do this underwater. Lots of people will want to watch if the tank gives way before the rock does?

Like this

For some of reason I can't post the link so here is a screen shot.

 

[McPuff]

Best bet is to try and "chew" away at the rock with some bone cutters or curved blade coral cutters that BRS carry. I have one of those and it's probably the tool I use the most for fragging and rock cutting.

https://www.bulkreefsupply.com/brs-large-curved-blade-sps-coral-cutter.html

 

[Tcook]

As rennjidk said. A flex drive with a cutoff wheel . You can get these to use on your BATTERY operated Dewalt drill or similar.

 

[Dburr1014]

As rennjidk said. A flex drive with a cutoff wheel . You can get these to use on your BATTERY operated Dewalt drill or similar.

If you drain the tank...
Or atleast clean all the bearing grease out of them??!