Anyone ever use Hydraulic Cement for bonding rocks?

[u4ick]

I am looking to bond some rocks together. I have seen E Marco Rocks 400 cement and was wondering if it's similar to Hydraulic Cement
It says its reef safe and can be put in aquarium right away with no pH issues or leaching issues.

I an needing to put this in the tank right away so I can't have any leaching time or pH issues. And I'm also going to need a substantial amount of whatever it is I use. Probably around 2-3lbs worth, so epoxy putty is off the list

Any other options would be awesome to know about.

[MondoBongo]

yes, i did.

it worked really well, but at the 6 month mark it started falling apart on me. i'm not sure if i mixed it or used it wrong, but it has started crumbling all over the place and destabilizing my rock work.

i didn't notice any other issues that i would attribute to it. i let mine cure for about a week before submerging it.

-edit-

i have some of the marco rock cement as well, but it took them forever to ship it, so i ended up using the kiwkcrete hydraulic cement in the mean time. i should have just waited and used the marco stuff.

[u4ick]

So the hydraulic cement degraded in the tank?

I just tried mixing up the Marco stuff and it was as brittle and crumbly as regular mortar mix.

I am needing something I can cover spaces between rocks that are covering PVC pipe (to be used in closed loop system) so that I don't see the pipe, and also want it to be the main support for overhangs and not rely on the PVC itself.
Also wanting to cover the pipe under the sand with something that will look natural in the event that it get dug up by tank inhabitants.

Guess I'll call Marco and ask about what I'm seeing. I thought this was what it was for but....

[MondoBongo]

Have you thought about using a thin layer of expanding foam and then using a clear epoxy to cover it with sand and rock to camouflage it?

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[u4ick]

Funny you say that. I was just thinking along those lines yesterday.

Think I'll use a combination of Holdfast 2 part epoxy and Marco E 400 for the majority of things structural and use the black tetra pond foam to help with the aesthetics and hiding of things, maybe use sand and rubble with it.

I think I didn't let the E400 cure long enough before I judged it's integrity. It actually seems to work just fine, however where only small amounts are used i'm not 100% convinced of it's gripping power, so for smaller areas I'll be using the 2 part epoxy.

Thanks for your input on the hydraulic cement.

[Flippers4pups]

Yes I have, but I also used fiberglass rod to add strength. Two years and only had a small piece crack.

I used quikrete hydraulic cement from Home Depot. There's a thread on RC called "reef ceramics" that I got the idea from.


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[McPuff]

Originally Posted by u4ick

I just tried mixing up the Marco stuff and it was as brittle and crumbly as regular mortar mix.

Guess I'll call Marco and ask about what I'm seeing. I thought this was what it was for but....

Sounds like you should have simply used more of the solution they provide. You'll want to get a thick mixture which doesn't drip after mixed. But you can't have it too dry either or it won't even stick well to the rock. The other thing that helps is to wet the rock prior to applying the mortar. I mortared some very large rocks together and they are not coming apart. The mortar supports the weight of the large rocks entirely in some joins. I let the rocks cure for about a month before submerging them in water for the first time... but Marco claims there is no cure time required (other than the initial drying). Because it's a hydraulic cement it should continue to fully cure underwater as well. I have been really happy with the product thus far and was happy I was able to go this route on my build. You can make some really cool structures that would otherwise be impossible.

[u4ick]

Originally Posted by Flippers4pups

I used quikrete hydraulic cement from Home Depot. There's a thread on RC called "reef ceramics" that I got the idea from.


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Thank you for the thread info, I will look into that.

So did you experience any leaching issues with alk or pH issues?
Did you use it right away or cure it out for a while?

Thanks

Originally Posted by McPuff

Sounds like you should have simply used more of the solution they provide. You'll want to get a thick mixture which doesn't drip after mixed. But you can't have it too dry either or it won't even stick well to the rock. The other thing that helps is to wet the rock prior to applying the mortar. I mortared some very large rocks together and they are not coming apart. The mortar supports the weight of the large rocks entirely in some joins. I let the rocks cure for about a month before submerging them in water for the first time... but Marco claims there is no cure time required (other than the initial drying). Because it's a hydraulic cement it should continue to fully cure underwater as well. I have been really happy with the product thus far and was happy I was able to go this route on my build. You can make some really cool structures that would otherwise be impossible.

I'm pretty sure I mixed up correctly. The consistency was like clay pretty much. after it "dried" I was expecting it to be pretty solid right away....kind of like the two part epoxy does....Spoke with Marco, they said its fully hard in about 24hrs.....he was correct in that, as I tested the pieces later and they seems pretty sturdy.

I wanting to use these products more for coverage than for the structural.

I'm creating a closed loop system for an eight foot long peninsula tank. All the plumbing will be inside the tank, and I'm making a funky manifold that will be covered by rock. I've been taking dry Pukani and using a hole saw, drilling out cores so I can slide the rock onto the PVC. This will hide the PVC and make some pretty cool structures as well while also being the water movement source. I'm needing the cement to help take some of the load off the PVC and to hide the PVC between rock pieces.

Thanks for the input

[spiraling]

Originally Posted by u4ick

Thank you for the thread info, I will look into that.

So did you experience any leaching issues with alk or pH issues?
Did you use it right away or cure it out for a while?

I used it right in my tank. I did not measure PH, but all the corals, fish, and inverts were fine. Like another person on this post my crumbled to dust in about 6 months. Twice. I won't use it again.

[Flippers4pups]

Mine sat for a week before it got wet. No issues with alk or ph. Over two years and is still solid.

[u4ick]

Originally Posted by Flippers4pups

Mine sat for a week before it got wet. No issues with alk or ph. Over two years and is still solid.

Thanks for the reply

[getindavan]

i used the quikrete stuff and no problems yet. stuff drys fast so mix in batches you can use in a few minutes. I put the rock structure in my tank the next day with water but no fish and my filter sock got kinda stiff i think it had something to do with the cement.

[Haasmetaldesig]

I might have to try this on my next tank


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[thejuggernaut]

Originally Posted by MondoBongo

yes, i did.

it worked really well, but at the 6 month mark it started falling apart on me. i'm not sure if i mixed it or used it wrong, but it has started crumbling all over the place and destabilizing my rock work.

i didn't notice any other issues that i would attribute to it. i let mine cure for about a week before submerging it.

-edit-

i have some of the marco rock cement as well, but it took them forever to ship it, so i ended up using the kiwkcrete hydraulic cement in the mean time. i should have just waited and used the marco stuff.

This was my experience as well. Overtime it began to get brittle and would fall apart when you would move the aquascape

[epstein]

DO NOT USE FOAM.... I did for approx 4 yrs. I even went as far to purchase the exact same 2 part epoxy used by large aquariums for their displays. It will become brittle . It will leach Phosphates It will slowly poison your tank. I was one of the first to utilize this method and I will be one of the first to say Dont

This was my successful 92 corner that was amazing with its foam and live rock walls..