The right waterproofing for a concrete tank

[Razvan]

Hello everyone, I'm new here and would like first to thank the Admin for inviting me to introduce myself. My name is Calin and live in Romania, Eastern Europe. I'm inbetween tanks right now but have some 10 years of reefing behind me. My next tank will look something like a 6000L (is that 1500usg?) concrete bunker with window holes in it. It is already built. In fact, it's part of the house's loadbearing structure, which is why I cannot allow any saltwater to reach the rebars. So here's my question: have any of you experimented with concrete saltwater tanks? What is a proven waterproofing system or material that will last decades? Thank you.

 

[AlexG]

One solution would be the product pond armor. Its a two part epoxy that can be used to seal cement. I used this product for my plywood tanks and it held up really well. I have linked their site below which includes some application videos for concrete.

https://www.pondarmor.com/

 

[Smarkow]

Would love to see pictures of this!!!

Also welcome to R2R!

 

[Blue Tang Clan]

Welcome to Reef2Reef! You will find many knowledgeable people here to help with all aspects of reefing!

 

[Razvan]

One solution would be the product pond armor. Its a two part epoxy that can be used to seal cement. I used this product for my plywood tanks and it held up really well. I have linked their site below which includes some application videos for concrete.

https://www.pondarmor.com/

Thank you. I will definitely look into it. My first thought was bitumen emulsion, if that is the correct term. It binds well to smooth concrete as well as glass. I would have used it to bind a glass lining over the concrete and then use silicone to glue a second glass lining over the first. And then the windows, as it were, woul be siliconed on to that. Any thoughts on this one?

 

[Razvan]

Would love to see pictures of this!!!

Also welcome to R2R!

Thank you! About the pix, the whole site is a terrible mess right now, and progress is painfully slow, but I promise to post some as soon as a decent view is available.

 

[BackToTheReef]

Welcome!

Have you seen the pentair? I believe it is the old Aquatic Eco-systems (Sweetwater aquatics??? Not sure which one, used to get a killer catalog full of aquaculture products back in the day and this stuff was in it) stuff. Not sure what kind of reputation it has in the hobby but considering it for use in my plywood/fiberglass build

Epoxy Paint Kits

<p>Epoxy paint is recognized by the EPA as nontoxic (after curing), is extremely durable and has excellent adhesion to a wide variety of materials.

pentairaes.com

 

[Razvan]

Thanks. I had somewhat overlooked epoxy as an option. I'll research the zillions of such products that are also around here, in Europe, to find the best rated for salt water. I wonder what they use in public aquaria. I assume the biggest ones are concrete.

 

[K7BMG]

Thanks. I had somewhat overlooked epoxy as an option. I'll research the zillions of such products that are also around here, in Europe, to find the best rated for salt water. I wonder what they use in public aquaria. I assume the biggest ones are concrete.

I was going to recommend that very thing. Contact the big public aquariums that is.

 

[Mooka151]

Hello everyone, I'm new here and would like first to thank the Admin for inviting me to introduce myself. My name is Calin and live in Romania, Eastern Europe. I'm inbetween tanks right now but have some 10 years of reefing behind me. My next tank will look something like a 6000L (is that 1500usg?) concrete bunker with window holes in it. It is already built. In fact, it's part of the house's loadbearing structure, which is why I cannot allow any saltwater to reach the rebars. So here's my question: have any of you experimented with concrete saltwater tanks? What is a proven waterproofing system or material that will last decades? Thank you.

Not that familiar with Pond Armor but Im very familiar with epoxy. Epoxy is a fantastic product but has its limitations and the integrity of the system will be based on its ability to bond to the substrate. If there is an imperfection, or contaminant on the concrete that prevents a bond, water will infiltrate and progressively cause the surrounding area to fail. It can be done and done successfully, but I feel there are better alternatives available, mainly fiberglass. The concrete would be coated with resin, then a fiberglass mesh, then resin and you can build it up to be fairly thick. Its how boats are made. With a thick enough build, your basically making a water tight tank inside of the structure and not relying on the bond of the system to the concrete. There are systems called resin chopper guns, that make the application seamless, if you can fins someone in your area that is capable.

 

[Razvan]

Not that familiar with Pond Armor but Im very familiar with epoxy. Epoxy is a fantastic product but has its limitations and the integrity of the system will be based on its ability to bond to the substrate. If there is an imperfection, or contaminant on the concrete that prevents a bond, water will infiltrate and progressively cause the surrounding area to fail. It can be done and done successfully, but I feel there are better alternatives available, mainly fiberglass. The concrete would be coated with resin, then a fiberglass mesh, then resin and you can build it up to be fairly thick. Its how boats are made. With a thick enough build, your basically making a water tight tank inside of the structure and not relying on the bond of the system to the concrete. There are systems called resin chopper guns, that make the application seamless, if you can fins someone in your area that is capable.

That sounds good! I was going to incorporate fiberglass mesh reinforcement anyway, in whatever product I chose. So this resin you mention is different from epoxy, as I understand. I'll give it a search. That's exactly what I want, a tank in tank. Thanks!