using hydraulic cement for stacking rock

[reef tank 2.0]

i decided to attempt to use the hydraulic cement to glue aquarium rock together.

after a few minutes the cement set and became hard, but did not hold the rocks together. the cement slightly cracked. so i pulled it apart and cleaned off the rocks to boyott that mission.

i also didnt like the fact that the cement was very dark in color compared to the white rocks.

1. has anyone else come across these problems? if so, what did you do to fix the "glue" aspect of it.
2. what did you do to change the color of the cement?

 

[CStrickland]

I thought hydrolic cement was just for like plugging basement leaks?
I used regular Portland cement to mix a loose, mortar-ish stuff with play sand. I used type II so it wouldn't raise ph. It's rock solid. I didn't bother coloring it, doesn't take long for algae and coralline to hide it.

 

[mmittlesteadt]

First of all, you can't use it like glue. Secondly, you are better off finding rock shapes that naturally fit together, drill holes in them and use rods for holding anything like ledges and such.

Thirdly, and most importantly because it dries fast you can't use it in a thin layer. You have to put your pieces together and then slop the cement into and around the joint and keep it securely together until the cement cures (typically about 5 minutes).

In this pic below of my tank, you can see some of the dark grey where the cement was used. Most of it is covered in algae and some coralline now (tanks only been running for a couple of months). I created 5 large shapes out of smaller rock and the cement. Then I put those together in a manner that holds without needing to cement those 5 large pieces to create the entire rockwork. I used a product called Dry-Lok. You can find it at almost any hardware store. Yes, it was meant originally for plugging leaks, thus the quick drying. It is totally reef safe and will not cause any water quality issues.

 

[tmz]

It is totally reef safe and will not cause any water quality issues.

How do you know that?What's Dry-Lok made of?

 

[mmittlesteadt]

It is totally reef safe and will not cause any water quality issues.

How do you know that?What's Dry-Lok made of?

I don't have the links to all the research I did on it handy. I spent about a month looking into it, and could not find one single thing that caused me to not want to use it, but many instances where it was used with success. It was used in my tank in such small quantities and it was widely used in larger quantities in many other builds, including very large ones. I feel comfortable recommending it. The "brand" I used was called Dry-Lok, but there are many different brands of hydraulic cement in use out there, all containing essentially the same ingredients.

I can't speak to how SPS or LPS might be affected personally because I only have softies, fish and other inverts and it has had no adverse effect in my tank, nor anyone else's who keep a lot more than I do, from everything I read on it's use.

Large public aquariums certainly aren't using Marco Rock and reef putty. How do we know the stuff sold by Marco is reef safe, and what's that made of?

Like anything else, if anyone wants to use something in their tank, they should research it first and decide for themselves.

 

[MondoBongo]

so i started playing with this last night for the first time. not quite what i expected, although i'm not really sure what i expected.

i ended up mixing it up thinner than i thought i should, almost like the consistency of heavy chocolate pudding, and kind of just globbing it on there. then seated the rocks, and used a gloved finger to mold it in and around as much as possible.

i'm going to go back today and see how it has cured.

i was originally going to use the acrylic rod method, but i have been having a devil of a time drilling through some of the pieces of BRS shelf rock i got. i've tried diamond studded hole saws for masonry and masonry bits with little luck, so i decided to give this a go.

 

[mmittlesteadt]

so i started playing with this last night for the first time. not quite what i expected, although i'm not really sure what i expected.

i ended up mixing it up thinner than i thought i should, almost like the consistency of heavy chocolate pudding, and kind of just globbing it on there. then seated the rocks, and used a gloved finger to mold it in and around as much as possible.

i'm going to go back today and see how it has cured.

i was originally going to use the acrylic rod method, but i have been having a devil of a time drilling through some of the pieces of BRS shelf rock i got. i've tried diamond studded hole saws for masonry and masonry bits with little luck, so i decided to give this a go.

Get the rock wet before you drill it.

I made the cement kind of the same consistency (like pudding) but let it set up for a little bit before applying it. It just takes a little practice with it until you get a feel for what consistency works best for you.

 

[CStrickland]

That's pretty much what I did mondo, except with regular cement that would be a mortar for structural use. I kinda slapped it all over the back like making a rock wall. On a couple joints I made little wax paper frames to hold more in place so it didn't drip away.

I liked how cement and aragonite has been used in a lot of diy rocks, seemed safe enough.

 

[KafudaFish]

If bonding rocks use the dry method.

Put the cement where you want it and place the rocks together. Use a spray bottle or even a spoon to wet it.

Keep adding cement and water until the cracks are filled then wet a finger to blend.

Then leave it all alone for a day as in don't touch or move it.

You can go back and fill.in and repeat.

Only issue could be a pH spike.

 

[MondoBongo]

Get the rock wet before you drill it.

I made the cement kind of the same consistency (like pudding) but let it set up for a little bit before applying it. It just takes a little practice with it until you get a feel for what consistency works best for you.

i actually tried with running water from my RODI waste line. it's just certain pieces. there are some areas that are very dense and i didn't want to risk fracturing large chunks of the piece.

i may revisit, depending on how well the cement mix worked for me. i feel like there is a bit of a learning curve with it.

 

[reef tank 2.0]

i was definitely trying to use it as glue. rather than forming cement around the sctual joint.

maybe i'll try that.

im assuming i could use jb water weld, right? does that work just as well?

 

[CStrickland]

Water weld isn't that sticky either. It's easier than cement to control, so you can moosh it into holes easier but still the way it holds is by "grabbing" the rock and setting hard. That's why people use superglue with it to stick frags

 

[homer1475]

Even JB Water Weld will not "glue" the rocks together.

What I did was stack my rock, then use JB to fill in the cracks and joints. My rock isn't "glued" together, but rather fit together like a puzzle and puttied in the joints to prevent toppling. Where I wanted a shelf, I made a "cradle" out of the putty and placed the ends of the rocks in that cradle.

When dealing with frags and frag plugs, I superglue the frag and/or plug to the putty, superglue the bottom of the putty, then push it into my rock. The superglue assures adhesion, while the putty sets up and holds stuff in place.

 

[kurt_n]

Yup... what homer said. While I haven't used JB, when you're using any epoxy don't think of it as glue. Think more in terms of using the epoxy/putty as "keystones" that you stick in strategic locations to keep your rockwork locked in place. You can also use it to build up an area of contact between rocks so that they mesh perfectly in those areas. Let that harden up, and then come in later and apply your "keystones" to lock it in place. In a few months, it'll all be covered in coralline and you'll be hard pressed to find the "seams" between the rocks.

 

[tmz]

I don't have the links to all the research I did on it handy. I spent about a month looking into it, and could not find one single thing that caused me to not want to use it, but many instances where it was used with success. It was used in my tank in such small quantities and it was widely used in larger quantities in many other builds, including very large ones. I feel comfortable recommending it.


There are anecdotes citing difficulties as well. While it might be ok depending on the composition of the particular product in your tank as you see it , it takes more than that supposition to unequivocally state as fact " it is completely reef safe"

The "brand" I used was called Dry-Lok, but there are many different brands of hydraulic cement in use out there, all containing essentially the same ingredients.

Including aluminum and impurities. It will also raise pH for some time in most cases . Fully curing it before putting it in a tank may help but the potential for aluminum toxicity during reactions does concern me:

This article has more on aluminum and toxicity:

http://www.advancedaquarist.com/2003/7/chemistry


Large public aquariums certainly aren't using Marco Rock and reef putty. How do we know the stuff sold by Marco is reef safe, and what's that made of?
I don't know of public aquariums that use Dry-Lok or other hydrolic cements for coral displays or macro rock for that matter. If you know what public aquariums are using it would be interesting to know.

Like anything else, if anyone wants to use something in their tank, they should research it first and decide for themselves.

Yes, I agree and always ask questions when absolute statements are made. Like :how do you know that? What's in it? etc.

 

[mmittlesteadt]

Yes I've come across the very things you mentioned in my research and the levels of these impurities are so low (even when a lot of hydraulic cement is used) that for what tiny bit was used in my tank just to keep the rocks together, it doesn't concern me much at all.

I've used poly filter in my tank just to see what might be pulled from the water and nothing even registers.

 

[tmz]

Well, I'm glad you are happy with the prodcut you chose and it hasn't caused discernible problems in the amounts you used. To be fair if it's completely cured and non reactive outside of the tank it might be fine but I'd be cautious with it .

While I think using polyfilter is generally a good step when contaminants are suspected , the color change in polyfilter isn't a useful as a test test for free metals like copper since that color change occurs at levels well above levels of free heavy metals toxic to invertebrates. Fish have a higher tolerance. It is useful in reducing higher levels though even though it won't color up until it's exhausted.

I'm not aware of anything to indicate it removes aluminum though; a reliable test on aluminum levels pre and post use would be helpful :

http://poly-bio-marine.com/faq.htm

from the manufacturer's link above:

What does a Poly-Filter® remove from an Aquarium?
Poly-Filter® sorbs excess organics such as amino acids, proteins, lipoproteins, dissolved organic matter, all forms of phosphates, tannins & humic acids and related complexes. Poly-Filter® also sorbs volatile organic chemical such as chloroform, bromoform, benzene, phenols and organophosphate insecticides/pesticides. All metabolic wastes are sorbed by Poly-Filter®.

 

[mmittlesteadt]

Oh yes, it sat outside my tank for a good month after construction. Then after that (long before I ever got around to putting it in my tank and filling it with water) my rocks soaked in vinegar baths for another month probably. Then they got another good washing before even putting them in my tank. It was probably another month before I filled my tank with water (much longer story why it took so long...suffice to say I went from going with all HOB to a sump in my basement).

 

[CStrickland]

TMZ you're scarin me!
Are these concerns with the additives that make the hydrolic type set up faster, or are you talking cement generally? If the whole point of the expensive hydrolic stuff is that it sets fast under water, it seems pointless to risk it if you are going to cure it out of the tank before hand...

Also, fwiw my big public aquarium (Boston) is a joke reef-wise. They just have some sad Xenia and anemones and stuff. Most of the customers want to see big fish and pet sharks, those tanks are all fake plastic coral, I don't think they give a lot of thought to aluminum or whatev.

 

[setsail4mexico]

so i started playing with this last night for the first time. not quite what i expected, although i'm not really sure what i expected.

i ended up mixing it up thinner than i thought i should, almost like the consistency of heavy chocolate pudding, and kind of just globbing it on there. then seated the rocks, and used a gloved finger to mold it in and around as much as possible.

i'm going to go back today and see how it has cured.

i was originally going to use the acrylic rod method, but i have been having a devil of a time drilling through some of the pieces of BRS shelf rock i got. i've tried diamond studded hole saws for masonry and masonry bits with little luck, so i decided to give this a go.

To make drilling a breeze use a hammer drill!