Plywood Tank Questions

[Kamau]

Hiya, I plan on constructing an 8x4x4 ft plywood paludarium for my basilisk. It will have a luxurious water area that's approximately 220 gallons (which I may or may not put fish/plants in). Now, I've run into some dilemmas when it came to the sealing part of my task. I first considered the traditional epoxy coating, which is fine other than the fact that it's a smooth surface. My lizard wouldn't be able to grab onto it for a climbing area, and if it did its claws would punch holes in the sealant (not to mention it's super expensive).

Then I came to pond liner, which seemed inexpensive but also it had its flaws. My lizard would and could utilize it for climbing, which would definitely rip the liner to ribbons. Not to mention it seemed to be a little testy about adhereing to things, which could also mean that with a little weight from my lizard in the wrong spot could simply pull it off. I'm not sure if any of those are realistic situations, but by the claims I've seen online I seem to be in the right ballpark.

Then I considered something I haven't heard of anyone using: concrete. It would definitely be water-proof, moderately priced, and not to mention the perfect climbing surface for my lizard that would also wear his nails down. The only backlash I see with this option is that concrete is probably unimaginably heavy, and would be a pain to move around even without water. I might apply it to each separate board before screwing it all together, and then going around the seams with some sort of sealant. I'm not sure. Thoughts, anyone?

 

[SnakeIce]

What about doing the tank in what makes sense to hold water, and then doing an insert that you surface with concrete or some other base to adhere the aggregate to. The two solutions don't have to be on the same surface.

 

[Sploke]

Generally with concrete you still have to seal it in some fashion...concrete itself isn't innately watertight. Quite the opposite, its very porous. You'd have to apply some soft of epoxy or topcoat over it to make it watertight enough to contain water. I think you'd be in the same situation as you would be with sealed plywood, at 5x the weight.

One option might be using plywood, but using fiberglass matting to build up some texture on the surface. You could either just lay it out flat, or build it some ridges, or cut up some matting into small pieces, mix with resin, and build up footholds or various areas for texture. You get the lighter weight of plywood, the watertight properties of the epoxy resin, and some texture on the walls. When I did my plywood tank I used resin that was tintable with acrylic paint so I was able to blend in some different colors for a more natural tone as well.

 

[pbeemer]

you might want to look in the paludarium section to see how others have solved these problems.

as snakeice said earlier, the volume which is going to be a pond will require a little more attention than the "dry" walls. however, there are a lot of successful methods.

there are a number of posts here and in the paludarium section showing how to use carved styrofoam as a base for a concrete (really just mortar) overcoat. the concrete can be dyed / pigmented to give you more a realistic surface; in your case, you can also mix in some (slightly damp) sphagnum moss to add character and texture to the result.

altho mortar is reasonably water resistant (people make backgrounds and caves which are completely submerged in their aquariums), you can improve the water resistance by putting one of the latex concrete admixture liquids. these are usually some sort of SBR latex, or occasionally acrylics. the microscopic rubber particles get trapped in the gaps and voids in the mortar and plug them. follow the instructions on the label; measure carefully, since a gross overdose of the latex will increase the water:cement ration beyond good design. the label may suggest holding water back to compensate for this.