DIY Rock Question

[seanarino]

Is it possible to make DIY rock without using the "tote full of sand" / molding technique? I can't figure out for the absolute life of me how that works, and I want to make a double arch-type shape in the future for a bigger tank (think: like a flat 'm' shape) but the GARF technique is hollow (which I don't want) and uses the sand technique (which I can't figure out). Is there ways of putting it on / in other things to make convincing looking rock that isn't a million pounds and made in a sand filled bucket? Maybe 'sculpting' it? Using a different type of mold? Covering something else with the aragocrete mix like PVC pipes or something?

 

[RocketEngineer]

Have you looked at gluing dry rock instead? Or employing that approach? If you can make a series of smaller rocks, building the arch out of those instead of trying for the arch in one step might be easier to achieve.

 

[seanarino]

Have you looked at gluing dry rock instead? Or employing that approach? If you can make a series of smaller rocks, building the arch out of those instead of trying for the arch in one step might be easier to achieve.

I originally tried dry rock and gluing for my 20g (originally 10g) but because of my lack of materials it was one of the most frustrating things I think I've ever done, LOL - I have no rock epoxy, no acrylic rods, can't drill the rocks... I had to use the "glue and cotton ball' method and my rocks are VERY QUESTIONABLY held together.

I liked the idea of a 1 piece arch because there was no way I could goof it up by picking it up and all the rocks falling apart. I wanted a "somewhat" thinner arch, but not so thin that it could be snapped apart. I plan on making it a solid (air quotes) piece because there was basically no chance that it'd come apart if I picked it up. Only thing is, I just realized I'd have to do it in two pieces anyhow because my aquarium is an old 1990's Oceanic brand 75 gallon and has that disturbingly large glass euro brace in the middle. I could make one of them the solid arch, and then the second piece the "extension" (the other end of the 'm') and then glue once they're in the tank.
I plan on also gluing the part that touches the glass to thick acrylic sheets before putting them down on bare glass because I'd cry if I did something to this tank that screwed it up, like scratching the bottom glass or a rock somehow falling over and cracking any of the panels because of my clumsy hands.

I also wanted to make one of those cool coral 'shelf tree' things but I hate the sand method and they're ridiculously expensive to buy, so I'll have to figure that one out or buy some Stax rocks and figure out how to go from there.

 

[Gtinnel]

If you glue dry rocks together using thin superglue and either rock dust or baking soda it forms an incredibly strong bond. There are several good videos about it on YouTube including one from Tidal Gardens.

I don’t know about the sand technique but I have heard of people making their own rock using a certain type of cement. I think @tbrown made his own…maybe.

 

[RocketEngineer]

I originally tried dry rock and gluing for my 20g (originally 10g) but because of my lack of materials it was one of the most frustrating things I think I've ever done, LOL - I have no rock epoxy, no acrylic rods, can't drill the rocks... I had to use the "glue and cotton ball' method and my rocks are VERY QUESTIONABLY held together.

I liked the idea of a 1 piece arch because there was no way I could goof it up by picking it up and all the rocks falling apart. I wanted a "somewhat" thinner arch, but not so thin that it could be snapped apart. I plan on making it a solid (air quotes) piece because there was basically no chance that it'd come apart if I picked it up. Only thing is, I just realized I'd have to do it in two pieces anyhow because my aquarium is an old 1990's Oceanic brand 75 gallon and has that disturbingly large glass euro brace in the middle. I could make one of them the solid arch, and then the second piece the "extension" (the other end of the 'm') and then glue once they're in the tank.
I plan on also gluing the part that touches the glass to thick acrylic sheets before putting them down on bare glass because I'd cry if I did something to this tank that screwed it up, like scratching the bottom glass or a rock somehow falling over and cracking any of the panels because of my clumsy hands.

I also wanted to make one of those cool coral 'shelf tree' things but I hate the sand method and they're ridiculously expensive to buy, so I'll have to figure that one out or buy some Stax rocks and figure out how to go from there.

Second comment first: to protect the bottom glass on my tank I use light diffuser. It’s not exactly easy to find anymore but my local big box store still carried it. In my current setup, I cut it to be a couple inches smaller than the bottom of the tank so it’s well hidden.

Regarding the gluing method, I started with more rock than I figured I would need. That way I could systematically find pieces that gave me three solid points of contact. I used gel superglue in a large bottle to place a glob at each contact point, then used a long thin stick to smooth out the glob. The key for me was then to use the spray bottle of hardener to instantly set the glue.

By using the gel, I could place glue where I wanted it, position the new piece, refine the glue appearance, then spray with the hardener to keep it where it was. Once the superglue had set for a few days, on a few pieces I went back and added the epoxy for extra support. A spare piece of rock let me push the epoxy deep into the connection plus got rid of the too smooth look.

That’s 5 separate structures, before the sand went in.

 

[tbrown]

I made Aragocrete rocks. One thing to remember is that you have to cure the lime out or you can have an alk or pH spike.

Portland cement and Aragonite sand. You can add smashed up water softener salt for more porous rocks.

Look up Aragocrete and you'll find several threads on here, on other sites, and on YouTube with a ton of information. I have a walkthrough of a couple I've done on here in my build thread and maybe a thread or two in the forums as well.
Using anything beyond the Portland Cement isn't recommended unless it is silca free so just check the label for that.

As others have stated, you can always smash rocks and glue them together with gel super glue and sand making the shapes you want/need.

 

[tbrown]

Probably half of the rock in my tank is homemade Aragocrete by me.

 

[19Mateo83]

Second comment first: to protect the bottom glass on my tank I use light diffuser. It’s not exactly easy to find anymore but my local big box store still carried it. In my current setup, I cut it to be a couple inches smaller than the bottom of the tank so it’s well hidden.

Regarding the gluing method, I started with more rock than I figured I would need. That way I could systematically find pieces that gave me three solid points of contact. I used gel superglue in a large bottle to place a glob at each contact point, then used a long thin stick to smooth out the glob. The key for me was then to use the spray bottle of hardener to instantly set the glue.

By using the gel, I could place glue where I wanted it, position the new piece, refine the glue appearance, then spray with the hardener to keep it where it was. Once the superglue had set for a few days, on a few pieces I went back and added the epoxy for extra support. A spare piece of rock let me push the epoxy deep into the connection plus got rid of the too smooth look.

That’s 5 separate structures, before the sand went in.

I used this gel superglue method also except I dusted the joints with baking soda to set the superglue. It’s super easy and makes VERY strong structures.

 

[tbrown]

The middle piece is a PVC sleeve I made for my return pipe. You can use the PVC as a frame and make the shape you want and cover it with Aragocrete. Make sure the sand covers the bottom of whatever container you use so the concrete doesn't stick to that and then I usually cover the rock with an inch or two of sand.

You can also use egg crate as a frame but it's pricey these days.

 

[seanarino]

The middle piece is a PVC sleeve I made for my return pipe. You can use the PVC as a frame and make the shape you want and cover it with Aragocrete. Make sure the sand covers the bottom of whatever container you use so the concrete doesn't stick to that and then I usually cover the rock with an inch or two of sand.

You can also use egg crate as a frame but it's pricey these days.

See now *this* is what i was wanting (in terms of a solid answer if people actually did this / if it was possible). I wonder if there's other things that are usable... I would *prefer* not to do PVC if only for the fact that it's... well, hollow. But then again, that saves on money instead of making a solid structure (less material used). I could leave an inch or so of it uncovered, and when the aragocrete dries I could theoretically cut that bottom part of PVC off flat to glue it to the acrylic sheet to protect my glass (don't want to use egg crate to protect my glass because of the way it could trap sand pockets) once the rock is fully cured, and then glue rubble rock or pieces of live rock around the remaining bit of exposed PVC to hide it...

 

[tbrown]

See now *this* is what i was wanting (in terms of a solid answer if people actually did this / if it was possible). I wonder if there's other things that are usable... I would *prefer* not to do PVC if only for the fact that it's... well, hollow. But then again, that saves on money instead of making a solid structure (less material used). I could leave an inch or so of it uncovered, and when the aragocrete dries I could theoretically cut that bottom part of PVC off flat to glue it to the acrylic sheet to protect my glass (don't want to use egg crate to protect my glass because of the way it could trap sand pockets) once the rock is fully cured, and then glue rubble rock or pieces of live rock around the remaining bit of exposed PVC to hide it...

Well these are in my fish tank so I've done it. The PVC I made as a sleeve for PVC and slipped it over my return pipe. I wrapped a piece of PVC in paper buried the ends, slipped the PVC out after it dried and the paper came out during the pre-soak.

 

[malacoda]

BRS sells E-Marco-400 Aquascaping Mortar ... which is fairly easy and clean if you're working with all dry rock.

Granted, the mortar will look smoother than the rock (much like the mortar between bricks), but once coralline and corals fill in, you can't really notice. Come to think of it, you could probably press sand onto it if you want as well.

If you're trying to work with wet rock, then zip-tying pieces together and then applying JB Waterweld to solidify the joints may be an option. Here again though, you will see the waterweld until it is covered in coralline and corals.

Either way, 2-3 medium sections rather than 1 solid finished rock fixture is the way to go ... not only because you have eurobrace, but also to be able to get the sections in and out with ease.

All it takes is one slight slip of big, heavy, awkward piece to scratch glass sidewalls ... or worse, crack a bottom pane.

***Ah, after that last post, I see what you're after now...

A foam core may be another option...

Foam Wall Instructable - A Full How-to, Step-by-Step Guide

Foam Wall Instructable- A Full How-to, Step-by-Step Guide 26g bowfront First things first, you need to realize that you need a foam wall in your tank! They are relatively easy to make and can transform your tank into one that all of your...

www.reef2reef.com

Diy foam rock back wall.

I just thought I'd show my foam rock wall DIY project for my nuvo 16 gallon.

www.reef2reef.com

How To Build Live Rock Wall

Step by step guide on how to build a live rock wall for your saltwater aquarium or reef tank. Guide and pictures included.

www.fishlore.com

 

[seanarino]

BRS sells E-Marco-400 Aquascaping Mortar ... which is fairly easy and clean if you're working with all dry rock.

Granted, the mortar will look smoother than the rock (much like the mortar between bricks), but once coralline and corals fill in, you can't really notice. Come to think of it, you could probably press sand onto it if you want as well.

If you're trying to work with wet rock, then zip-tying pieces together and then applying JB Waterweld to solidify the joints may be an option. Here again though, you will see the waterweld until it is covered in coralline and corals.

Either way, 2-3 medium sections rather than 1 solid finished rock fixture is the way to go ... not only because you have eurobrace, but also to be able to get the sections in and out with ease.

All it takes is one slight slip of big, heavy, awkward piece to scratch glass sidewalls ... or worse, crack a bottom pane.

***Ah, after that last post, I see what you're after now...

A foam core may be another option...

Foam Wall Instructable - A Full How-to, Step-by-Step Guide

Foam Wall Instructable- A Full How-to, Step-by-Step Guide 26g bowfront First things first, you need to realize that you need a foam wall in your tank! They are relatively easy to make and can transform your tank into one that all of your...

www.reef2reef.com

Diy foam rock back wall.

I just thought I'd show my foam rock wall DIY project for my nuvo 16 gallon.

www.reef2reef.com

How To Build Live Rock Wall

Step by step guide on how to build a live rock wall for your saltwater aquarium or reef tank. Guide and pictures included.

www.fishlore.com

! I didn't even think of the foam! I wonder how I'd be able to make an arch with it, since this is for back walls.... Hmmmm. Thinking: egg-crate internals, figure out how to tie rocks to egg crate, spray foam over egg crate, dry, trim, silicone + aragonite sand, cure, glue to acrylic sheet, plop in tank...

This also means I could make the piece as one large piece and then cut it into three to place it as well so I don't have to think "hmm, I hope this works and I don't have it severely messed up".

I don't even know if you know but you're like, my savior right now.

 

[ISpeakForTheSeas]

Totally possible. A lot of this has been mentioned, but some of this may still be helpful (post #7 from the second link in the top quote discusses some alternative methods to the sand casting):

I'm not familiar enough with plasti-dip and agrocrete to know if your suggested method would work, but I know Paul B has a similar method he used:

Build your own rock for practically free

Make your own rock When the hobby started there was no live rock for sale, as a matter of fact, there wasn’t even dead rock for sale. We used dead, white bleached pieces of coral to decorate our tanks and we bought that in a furniture store...

www.reef2reef.com

If you want a different way that can be used for this (though it would likely be more difficult), then this one works too:

DIY Rock Tutorial/Info Thread (Rocks, walls, floors, etc.)

Joining a new forum is kinda like starting fresh for me, and I definitely love to contribute when I can. I've casually scanned the threads in this area and haven't seen much in the way of DIY rocks and rock projects. Since making DIY rock is my business, I'd like to think of myself as somewhat...

www.reef2reef.com

I know this question was asked a month ago, but you could probably do either a DIY rock wall (see the first link below) or a DIY pond foam wall (see the other links below):

DIY Rock Tutorial/Info Thread (Rocks, walls, floors, etc.)

Joining a new forum is kinda like starting fresh for me, and I definitely love to contribute when I can. I've casually scanned the threads in this area and haven't seen much in the way of DIY rocks and rock projects. Since making DIY rock is my business, I'd like to think of myself as somewhat...

www.reef2reef.com

Foam rock wall 8 years old

so I just wanted to post up a long term report about my foam rock wall. It is just over 8 years old. And has held up great i did allot of reading on other forums about it and i decided to go with touch n foam pond foam i got it off e-bay for $8 A can. i chose this foam because on the front...

www.reef2reef.com

Build Thread - Foam Wall Instructable - A Full How-to, Step-by-Step Guide

Foam Wall Instructable- A Full How-to, Step-by-Step Guide 26g bowfront First things first, you need to realize that you need a foam wall in your tank! They are relatively easy to make and can transform your tank into one that all of your friends are envious of. DISCLAIMER: I am responsible...

www.reef2reef.com

Diy foam rock back wall.

I just thought I'd show my foam rock wall DIY project for my nuvo 16 gallon.

www.reef2reef.com

 

[seanarino]

Totally possible. A lot of this has been mentioned, but some of this may still be helpful (post #7 from the second link in the top quote discusses some alternative methods to the sand casting):

Oh! Thank you!!

 

[Paul B]

I have always made most of my rock

Build your own rock for practically free

Make your own rock When the hobby started there was no live rock for sale, as a matter of fact, there wasn’t even dead rock for sale. We used dead, white bleached pieces of coral to decorate our tanks and we bought that in a furniture store...

www.reef2reef.com