# Concrete/Cement Background



## ExoticPocket (Dec 23, 2010)

So. I'm planning on doing a big tank and I want to do a concrete/cement background. Can this work??? I have searched for some threads but theres not much. I want do do one like the ones by Brain Kubicki did. Heres a video of one. 



 Ok so has anyyone done this before? Tips, tricks cause I don't know anything about this? Would it leak chemicals or anything?

Thanks
Alex


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## CVB (May 30, 2011)

I would be worried about some chemical effects of cement backgrounds on plants, primarily. In aquaria, in my experience, it is advisable to build structures, let them cure for a month or two constantly being rewetted, then sealing them completely in epoxy to avoid leeching. You get severe PH problems with unsealed concrete in tanks. For frogs, it might be hard to say. I imagine you'd be unable to rear tads in tank water with a severely elevated PH and it might negatively effect plants, but the one in the video seems perfectly healthy and I don't quite see the sheen of epoxy (it may be there, however, video is pretty hard to see).

Aside from that, I might be a bit worried about the immense weight of concrete structures. Most likely what you'd want to do is use expanding spray foam or cut insulation foam (pink wall foam works well) to create the shape of your structure, then cover it in grout colored to your taste, then seal over that. Terrariums tend to have relatively thin glass that isn't really made to support the weight of a giant wall of rock when moved around or placed on uneven surfaces, and a typical viv needs to be moved periodically and usually finds itself on racks and other fairly unstable structures.

Hopefully others with directly relevant experience can weigh in on the viability of such a structure / address the concerns above.


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## ExoticPocket (Dec 23, 2010)

The weight would probably be an issue its just that the tank looks soo cool. I'll contact him and see how he did it. So if I did do it with the concrete way would I build the sturcture and then let it cure then apply epoxy? 
Thanks


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## CVB (May 30, 2011)

That is how we do it for submerged aquarium applications, yes, but it might be possible to go unsealed in a terrarium, but you would definitely want to check with someone who has done it before successfully. The reason for sealing it in an aquarium is that cement is quite caustic and raises the PH of water in contact with it until it is fully cured, and that can take a lot longer than people realize. Once you seal it in a few layers of epoxy it is, if you do a good job, completely inert. When in doubt, and it is possible, I tend to think it best to seal anything potentially hazardous in epoxy, polyester (fiberglass resin), or acrylate (superglues), depending on size and where it is being used. Only disadvantage is all that stuff tends to be very shiny, which matters a lot less underwater than out in the air where it will reflect light back at the viewer.


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## ExoticPocket (Dec 23, 2010)

I'm planning on having a water fall and stream like he did so I'm probably gonna do the whole tank in epoxy. I can't tell in the video but can you tell if he just made the stream side and then filled it with gravel?
Thank you


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## melbel (Oct 5, 2010)

I made a fish pond out of concrete and had to tear it down because it killed all the fish. I had the water tested and everything. I was told that the concrete leaches out chemicals that kill fish. I would assume if that is true that it would'nt be good for frogs either.


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## ExoticPocket (Dec 23, 2010)

Did you seal it in epoxy?


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## melbel (Oct 5, 2010)

ExoticPocket said:


> Did you seal it in epoxy?


Nope, that is where I went wrong. You live, you learn.


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## RNKot (Jun 9, 2010)

Old but decent thread
http://www.dendroboard.com/forum/members-frogs-vivariums/22002-60-gallon-construction.html
note *arielelf* is rebuilding it now & have new
http://www.dendroboard.com/forum/members-frogs-vivariums/69174-exo-terra-65g-build-pic-heavy.html


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## CVB (May 30, 2011)

That is an absolutely beautiful and technically advanced application of what I very crudely described above. Pretty amazing idea to pull out the leachable basic material with vinegar alongside the normal long-cure method. The final product is beautiful and clearly stable over the long term. That's the way to do it right there, ExoticPocket, and probably one of the best jobs of it I've ever seen done. Thanks for the links RNKot!


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## ExoticPocket (Dec 23, 2010)

Thanks for the links man. I think that will work but I'm not sure what Brian Kubicki. I don't think he did the foam because I have the book written by him and it has a picture of the tank and it just looks a lot like cement. It also looks shiny so he might have coated it in epoxy.


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## ExoticPocket (Dec 23, 2010)

OK so I looked at his other videos and he has the same background in a different tank and he said that it was all cement... So, which cement can I use? Portland cement or something?


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## mordoria (Jan 28, 2011)

Im going to visit Brian in a few months. Ill ask him when I get there.


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## ExoticPocket (Dec 23, 2010)

Ok. Thank you. I'm super jealous of you now


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## npaull (May 8, 2005)

I've done it on a 40 breeder. It looks good. But it's enormously, enormously heavy - and I did concrete over foam, not just straight concrete. I don't think I'll ever do it again just because of how incredibly heavy it is. It's a liability to move. I would never do it in a really large tank unless I were positive it would essentially never be moved.

And by the way, I don't move tanks very much. Once a year absolute tops to make small rearrangements. But it's still too much of a pain.


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## ExoticPocket (Dec 23, 2010)

Yeah. The waits gonna be an issue but I have only moved my tank once and that was pushing it down to the edge of the "rack". The "large" tank is gonna be probably a 18x18x24 or a 24x18x24 exo-terra. I'm only saying big because it will be the biggest of my tanks.


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## Okapi (Oct 12, 2007)

concrete backgrounds have been done:
40 gallon


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## davescrews (Dec 11, 2008)

here is mine-

http://www.dendroboard.com/forum/members-frogs-vivariums/47680-large-vivarium-works.html


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## ExoticPocket (Dec 23, 2010)

Thanks for the links guys. 
davescrews- Is the backgroung just made of cement or foam covered with cement and then painted with epoxy?


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## davescrews (Dec 11, 2008)

window screen covered in cement with epoxy over the cement in some areas


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## ExoticPocket (Dec 23, 2010)

Is the window screen to hold the cement to the wall? What cement did you use?


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## davescrews (Dec 11, 2008)

The window screen is stapled to the plywood back and was intended to provide the initial contours for the "rock work" so the concrete would not have to be several inches thick. It was a mix, about 60% mortar mix and 40% hydraulic with the liquid style pigment and acrylic fortifier added as well.


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## ExoticPocket (Dec 23, 2010)

Do you by that a Home Depot? Do you need the pigment or the acrylic fortifier?
Thanks btw


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## davescrews (Dec 11, 2008)

Yup, everything came from home depot. I don't know if you "need" the fortifier but it sure couldn't hurt and without the pigment the concrete will cure almost white in color. 

here is a product list of what I used:

Quikrete 60 lb. Mortar Mix - 1030016 at The Home Depot

Quikrete 20 lb. Hydraulic Water-Stop Cement - 1030076 at The Home Depot

Quikrete 1 qt. Concrete Acrylic Fortifier - 1030110 at The Home Depot

Quikrete 10 fl. oz. Charcoal Liquid Cement Color - 1030855 at The Home Depot


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## ExoticPocket (Dec 23, 2010)

Do you remember how much it cost in total cause I can't find the prices? Did you do anything for curing or just let it sit for a month?
Sorry for all the questions... I'm just trying to get stuff right  hahaha


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## davescrews (Dec 11, 2008)

I don't remember, I covered two 40" x 72" areas. I want to say I used about 400lbs. of concrete. To cure it I covered it with paper towels and sprayed it down with water several times a day for 2 or 3 weeks. After that I sprayed it with a diluted muriatic acid wash (50% acid 50% water) several times before setting it up as the monitor cage. It was then misted several times a day for a year or better before it was used for frogs.


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## ghettopieninja (Jul 29, 2008)

you could use one of the many epoxy products from Polygem that are designed specifically for sculpting/casting in animals enclosures. Some of them are very easy to work with and building a wall like those in Brian Kubicki's video would quite easy, and totally non-toxic/inert. 

Zoopoxies - POLYGEM, Inc.


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## ExoticPocket (Dec 23, 2010)

That very useful. But I'm kinda confused... Is that all epoxy or cement?
Thanks


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## VivariumWorks (Feb 27, 2008)

Hmmmmmm....

It would appear this hobby is in need of a low alkalinity, low weight, waterproof "cement" product that cures in days rather than months, and is already in the proper ratios for use as a layup over foam, as a sculpting medium, or a casting medium. One that doesn't need to be sealed with epoxy, and is almost as cost effective as Portland cement.

Well good thing I'm a chemist.

Above material already custom formulated, and in the testing phase now.

Next is manufacturing and packaging.

Doesn't do any good at the moment, but a hobby wide answer is on its way.


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## ExoticPocket (Dec 23, 2010)

Thats very cool VivariumWorks. Do you have an ETA?


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## VivariumWorks (Feb 27, 2008)

Not yet. I WANT to have it available when I launch my product line, but we'll see. The issue at this point isn't making small amounts, its making enough so when I get 10 people wanting some at the same time it doesn't take me 2 weeks to get it to them.

That and just because initial trials are promising, doesn't necessarily mean too much. I wan't to do more testing on it to ensure long term stability.

But I'm pretty happy with it so far and I can't think of any reason why it would have issues once cured, but stranger things have happened.



At this point what I would do is use only "hydrolic cement" with large volumes of sand as filler. Use cold water to reduce the set rate. Then after it has set, either soak it in water changing it out every day, or spray it down with water everyday. Do this for at least 1 week, but probably longer will be needed. On your last day of soaking add a small volume of vinegar to the water. Don't add too much as this could do more damage than good. You could do all that or seal it with an epoxy. NOT polyester resin. Never use polyester resin on cement. The CaO reacts with the polyester and yellows it and delaminates it. Not to mention polyester resin's nasty habit of leaching toxins into the water. I use to use it but had a lot of issues with it so now I only use epoxy.


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## ExoticPocket (Dec 23, 2010)

Do you know where you can get hydrolic cement? And by adding sand what ratio. 2:1 cement to sand? What exactly does the vinegar do?


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## VivariumWorks (Feb 27, 2008)

You can get "hydrolic cement" known as waterstop cement at HomeDepot/Lowes in a 20lb bucket under quickcrete brand. This is a mixture of Portland Cement and Calcium Aluminate Cement. The high alumina content causes a faster reaction and less of the very basic intermediate phase occurring in portland cement. However it will still change water's pH to 11 in an hour due to the PC content. Its a good option with whats available, but its far from ideal.

Yea I would try at least a 1:1, but a 1:3 should still work. The amount of sand you use will effect how gritty the texture is and how easy it is to work with. the more sand you use the less PC your using which will reduce the amount of pH spike you'll see.

Use COLD water. If you don't it will set in like 3 minutes. If you have to re-temper it (adding more water to the batch you've already added water to), do so in small amounts. This can really reduce the structural properties of the cement so try to use small batches instead of big ones. Also keep in mind the exotherm off this fast setting concrete can be plenty enough to burn the crap out of you so use thick gloves and don't use large batches at a time unless your pouring it into a mold.

The idea behind vinegar is that it will react with the excess Ca(OH)2 intermediate (what causes the pH to rise when concrete "cures"). The problem is the acid can also react with the final product of cement as well. So you want just enough to help "neutralize" the uncured intermediate but not enough that it begins to eat away at your cured cement.


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## ExoticPocket (Dec 23, 2010)

Will the hydrolic cement hold water? I'm planning on using it as a barrier, would that work?


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## VivariumWorks (Feb 27, 2008)

No, not well. You'll be better off using plexi that you then cover with the cement to make it not look like plexi. Cement is too porous in thin sections.


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## ExoticPocket (Dec 23, 2010)

The "barrier" would be 2-3 inches thick and 3 inches tall... Would that be too thin?


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