Best Putty/Glue for Dry Rock

[Wandering Albatross]

My rocks are 100% 'gravity snugged' in there-- but I don't have any powerful fish. If I were to use E-Marco (as I have in the past), I would only cement about 2 or 3-rocks in groups that fit together. More than that get really heavy to lift out of the tank.

That’s about how my reef is set up, but everyone is small, and even my 2” turbos can hang off the side of any rock without knocking it over. I just don’t know how strong an urchin is, and whether or not it can move 6” rocks. The hope is to eventually have corals encrust over the seams.

 

[twentyleagues]

Both my tanks are at least 3 structures to make it easier to remove if needed. Notice I said easier not easy.

 

[W31Olds]

I also used Marco Rock Mortar. Good stuff, just make sure you mix the acrylic correctly or you could run out.

 

[Renfield42]

I stacked my rock dry and made sure everything was stable with no adhesives. I then bonded them with super thick CA and epoxy putty. It has worked well.

The key is that things are self supporting first. It puts less of a demand on the adhesives, no matter what you use.

 

[JumboShrimp]

Well said.

 

[Bryman]

I found this to be incredibly strong and fast-acting. Mix it thick and use more powder than you think, then apply fast. https://www.bulkreefsupply.com/rock-lock-aquascaping-cement-caribsea.html

 

[Wandering Albatross]

I stacked my rock dry and made sure everything was stable with no adhesives. I then bonded them with super thick CA and epoxy putty. It has worked well.

The key is that things are self supporting first. It puts less of a demand on the adhesives, no matter what you use.

I guess the big question then, assuming everything is snug and self supporting already, is it really worth using adhesive if the fish are relatively small? The only thing I’m really concerned about is the urchin, everyone else to my knowledge isn’t interested in or strong enough to knock over 3-5 lb rocks.

Proposed stocking includes:
Blue spot puffer
Coral beauty angel
Melanurus wrasse
Undecided dottyback
Pair of skunks or clarkiis
Ruby dragonet
Undecided blenny
Diamond sifter goby or jawfish
Purple firefish
Linkia or sifter star, depending on goby
Short spine urchin
Assorted larger CUC

Probably something else on my list too, but these are the main ideas, with the puffer and angel being non-negotiables. Maybe rogue tomini from the 150g, maybe rogue flametail blenny from the 150g, if they can behave. Are any of these known for moving scaping-sized rocks?

 

[exnisstech]

E Marco 400 here if I want to build structures. It's pretty much like mortar where the joint becomes stronger than the material being bonded. I tack the rocks together with super glue gel then go back over and fill the joints with the 400.
For frags I use superglue gel/ putty/gel sandwich. For the putty I use JB water weld.

 

[painter1982]

This BRS video explains a little

 

[D.WhiteShark]

That’s a couple votes for E-Macro. I’m looking at the 5lb kit through BRS. Would that be enough for 75-80 lbs of rock, assuming the rock is stacked snug already?

Plenty, posibly with left overs for later. mix in small batches that you can use before it sets up.

 

[Wandering Albatross]

Any urchin keepers able to offer insight on what they can and can’t bulldoze?

 

[Renfield42]

I guess the big question then, assuming everything is snug and self supporting already, is it really worth using adhesive if the fish are relatively small? The only thing I’m really concerned about is the urchin, everyone else to my knowledge isn’t interested in or strong enough to knock over 3-5 lb rocks.

Whether it’s necessary to glue it all or in part depends on what kind of scape you’re doing.

I was more concerned with making sure I didn’t accidentally cause a rock slide during maintenance some day. That being said I have some rocks sitting isolated on the sand with zoas and acans that my crabs frequently move while burrowing under them. They are way stronger than I would have ever guessed.

You could always use adhesives on the lower half / base of the rock work and stack the upper part without glue. That’s what I’ve done, although the majority of my scape is glued. I can remove some of the rocks for work if need be and not worry about screwing things up.

 

[Wandering Albatross]

Whether it’s necessary to glue it all or in part depends on what kind of scape you’re doing.

I was more concerned with making sure I didn’t accidentally cause a rock slide during maintenance some day. That being said I have some rocks sitting isolated on the sand with zoas and acans that my crabs frequently move while burrowing under them. They are way stronger than I would have ever guessed.

You could always use adhesives on the lower half / base of the rock work and stack the upper part without glue. That’s what I’ve done, although the majority of my scape is glued. I can remove some of the rocks for work if need be and not worry about screwing things up.

The goal is to have a solid base of rock sitting on egg crate on the bottom glass, so nothing can be destabilized by burrowing near it, as they can't get under the base rock in any place I didn't leave a distinct cave for them. Then 2/3 or more of the tank would be cave systems, stacked, or glued as needed. It does have less space for foundation rock though because of its 12" width, which might make scaping harder, with or without adhesive. But as a semi-aggressive 'hood' tank, I need the extra rockwork for hidey-holes. Ideally it will be structured as 1-2 large islands with a sand bar around the perimeter.

I suppose I could also use a couple reef rods if the rock is porous enough, for the taller parts of the structure. Still mobile enough to remove rock if needed. The fact that the tank is narrow and tall is a bit of a nuisance, but there's no way I'm turning away a free tank. My 150 is 24" wide so I had more wiggle room for balancing, and my rock is far enough from the glass that it couldn't be uprooted or tipped and smack the side of the tank.

As a side note, what do y'all think of the tomini (4-5") going in there? He stands accused of killing/harassing several other fish in the community reef. Would he have a chance in this semi-aggressive tank? It would be a downsize for him, but he can't stay where he is, and if not in the 75g, he has to be sent on his way. Shape-wise would he be a problem for the coral beauty? Is it too much of a risk to anyone else, if he's added last, considering he has been a problem to some fish before? Would a dither fish help?