Another DIY Plywood Build 400 gallon - Mostly Pics =)

[jjohnwm]

Just spitballing here...

Leave the glass in place. Attach a new interior "liner-box" made of wood or whatever. Have the edges of the liner extend slightly over top of the edges of the glass...I am assuming the glass is flush with or even below the current interior?

Seal the new interior with epoxy, allow full curing, then apply a thick bead of silicone along the edge of the epoxy-sealed wood, allowing it to completely fill the glass/wood gap.

This can definitely be made to work and to be waterproof. You'll need to work carefully to minimize the visibility of this from the outside. Will likely need to apply some sort of mouldings or picture-frame edgings externally to completely conceal this fix from view; not ideal, of course, but still far better than abandoning this project.

 

[Arkangel77]

Seal the new interior with epoxy, allow full curing, then apply a thick bead of silicone along the edge of the epoxy-sealed wood, allowing it to completely fill the glass/wood gap.

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This "MIGHT" be possible but it seems sketchy at best to me. I just don't want to invest a bunch of money and time into this for it to just fail again. I plan on stocking with Discus. I cant have the tank going to crap after I put several K worth of stocking into it. I was lucky I discovered this during a time when I was changing the tank around and there was only a few fish in there. NOT likely to be that "lucky" again

 

[jjohnwm]

Or...maybe just build a frame around/over the glass, made out of epoxy-sealed wood. Silicone seal it as described above. Re-finish the rest of the interior as you wish.

 

[Arkangel77]

Or...maybe just build a frame around/over the glass, made out of epoxy-sealed wood. Silicone seal it as described above. Re-finish the rest of the interior as you wish.

that Might Work?

 

[thebiggerthebetter]

Sorry, not much time I have to read everything with care but the only assured way is probably to have the water pressure press from the inside out on the glass and the silicone between the glass and the tank. That's the only hope to have a water tight glass-to-tank seam (in the absence of bolting the glass to the tank and thus squeezing the silicone gasket).

 

[fishdance]

If you are after something that seals onto (on top) of glass then consider liquid rubber paint as a liner. It comes in a variety of colours and handles flexibility up to 800% stretch.

Do use a commercial grade product. I'm not sure about products sold in USA but something like this https://liquidrubberusa.com/products/liquid-rubber-waterproof-sealant?variant=37926576783509

I have not used this on wooden tanks.

This is the product (unsure if too link is the same). https://www.coating.com.au/rubber-coating-australia/

 

[Arkangel77]

If you are after something that seals onto (on top) of glass then consider liquid rubber paint as a liner. It comes in a variety of colours and handles flexibility up to 800% stretch.

Do use a commercial grade product. I'm not sure about products sold in USA but something like this https://liquidrubberusa.com/products/liquid-rubber-waterproof-sealant?variant=37926576783509

I have not used this on wooden tanks.

This is the product (unsure if too link is the same). https://www.coating.com.au/rubber-coating-australia/

Not Sure hoe I feel about Liquid Rubber? If I did another Plywood I would have to rebuild from scratch - fiberglass-then Epoxy. IMO

 

[fishdance]

why can't you cut out the glass? Piano wire? I use a thin flat knife I bend in a table vice to create left or right sided blades.

Then fiberglass under and silicon the glass back.

 

[Arkangel77]

why can't you cut out the glass? Piano wire? I use a thin flat knife I bend in a table vice to create left or right sided blades.

Then fiberglass under and silicon the glass back.

Thats the ONLY way to save this current tank but I dont see how I can get the glass out without destroying it. The silicone is VERY thick and the glass is sitting in a Pocket. So silicone on 2 sides - 3/4" on the edge/side side and then 1.5" on the front seam. No way to get piano wire in a corner like that. I thought of maybe trying to use a vibrating saw tool. The hardest part is getting threw that thick front seal!!!

 

[Dione]

This sucks, sorry your dealing with issues in a build you worked so hard on. On the flip side thank you for bringing to light a failed plywood build. I have a feeling there are quite a bit more on this site that don’t get discussed out of embarrassment. But bringing this type of thing to everyone’s attention is what helps this particular part of the hobby so I thank you. I’ve been planning a huge build and this is just the type of thread I needed to read. I know it’s been some time since the build but I’m curious as to your prep and cure times in between coats. What did you sand the wood with prior to epoxy? Did you clean it thoroughly afterwards? And you mentioned that you used more coats than recommended, could that have caused an issue? Not trying to be critical in any way but just trying to learn.
Now here is where I can help you out. If you want to cut the glass out I’d recommend a windshield removal (cold knife) tool like I use daily. Not sure if you can get to the inside of the tank easily but if you can then this will work like a charm. The blades have a 90 degree bend designed to reach under the glass and cut the adhesive. They also come in various lengths if needed. I use these to cut out windshields which are held in by urathane which from my experience is much denser than silicone. Should cut like butter