Good/bad idea - adding a layer of acrylic to bottom panel of plywood tank?

[billybobjoel]

Hello, I'm thinking about making a tank with four glass panels using a plywood base. I've seen many people use epoxy, liquid rubber, or fiberglass to coat plywood base and then silicone the glass panels, but I was thinking about using a thin layer of acrylic on top of the plywood base to waterproof it instead. My thinking was this could be cost-effective and potentially more water-proof. I am new at this so let me know if it is a terrible idea . Thoughts? Good/bad idea?

 

[crusso1993]

Hello, I'm thinking about making a tank with four glass panels using a plywood base. I've seen many people use epoxy, liquid rubber, or fiberglass to coat plywood base and then silicone the glass panels, but I was thinking about using a thin layer of acrylic on top of the plywood base to waterproof it instead. My thinking was this could be cost-effective and potentially more water-proof. I am new at this so let me know if it is a terrible idea . Thoughts? Good/bad idea?

I don't see why it would not work. Would you be using silicone to seal it? It could be cost-effective depending on the size of the tank.

Maybe @AlexG can offer some insight as he has extensive current experience with plywood tanks. What say you, Alex?
Check out his build in the link below...

Monster Build - AlexGs Basement Plywood Build 2 displays one system.

So I had to move to IL for work which forced me to tear down my 120gallon display. I had a basement sump with a large refugium tank and water storage. I had a great setup and the tank did really well. It was sad to tear it all out but it had to go when I got the word I was moving. I did not...

www.reef2reef.com

 

[AlexG]

Thanks for the mention @crusso1993. While you could use a layer of acrylic to line the bottom of an aquarium to prevent damage from falling rocks it would not be an ideal solution for waterproofing in this case ( I used PVC for this on my big FOWLR plywood tank). While acrylic is an excellent material for making aquariums it does not play nice with other materials when it comes to forming bonds that are water tight. When acrylic is mixed with other materials a pressure seal with a gasket is needed to make a waterproof seal as it cannot easily form a bond using adhesives. It also means that if you use acrylic with a pressure seal method that it would need to be the correct thickness to support the water pressure that it will need to support. A thin piece of acrylic would have the potential of buckling underwater pressure which could cause a catastrophic failure. When plywood is coated with an epoxy like pond armor it soaks into the wood creating a very strong layer of water proofing that is further enhanced with additional layers or epoxy along with fiberglass. When you use a high quality RTV with glass and epoxy coated plywood it will form a bond that will be able to hold back water pressure when applied properly.

 

[crusso1993]

Thanks for the mention @crusso1993. While you could use a layer of acrylic to line the bottom of an aquarium to prevent damage from falling rocks it would not be an ideal solution for waterproofing in this case ( I used PVC for this on my big FOWLR plywood tank). While acrylic is an excellent material for making aquariums it does not play nice with other materials when it comes to forming bonds that are water tight. When acrylic is mixed with other materials a pressure seal with a gasket is needed to make a waterproof seal as it cannot easily form a bond using adhesives. It also means that if you use acrylic with a pressure seal method that it would need to be the correct thickness to support the water pressure that it will need to support. A thin piece of acrylic would have the potential of buckling underwater pressure which could cause a catastrophic failure. When plywood is coated with an epoxy like pond armor it soaks into the wood creating a very strong layer of water proofing that is further enhanced with additional layers or epoxy along with fiberglass. When you use a high quality RTV with glass and epoxy coated plywood it will form a bond that will be able to hold back water pressure when applied properly.

Thanks for coming in, @AlexG ! One of these days, I'd love to come by and see your set up in person. I'm not far from you, in Algonquin. Of course, I mean as long as it's good with you. If not, no worries as I get it.