120g Plugging Corner Overflow Holes

[FullSend]

I've ended up with a 4'x2'x2' - 120 gallon aquarium. It's your standard black plastic frame with a corner overflow. I want to permanently plug the holes through the bottom with glass and silicon. I've used an online calculator that's saying .25" thick glass would have a safety factor of 1 and .35" would be ~ 2x.

I'm thinking a 3/8" thick piece overlapping the holes by 1" in any direction should work. Anyone think this is a bad idea?

 

[Crabs McJones]

Is there a reason you don't want to use the overflow?
Instead of permanently blocking them off, I'd put bulkheads in them and glue a plug into that. That way if you for whatever reason want to use the overflow some day, all you have to do is replace the bulkheads and plumb it.

 

[FullSend]

Is there a reason you don't want to use the overflow?
Instead of permanently blocking them off, I'd put bulkheads in them and glue a plug into that. That way if you for whatever reason want to use the overflow some day, all you have to do is replace the bulkheads and plumb it.

Nothing more than personal preference,
I'm confident I could remove the glass if I wanted. I'm also planning to drill one of the sides for returns and a new overflow.

 

[Fish Fan]

You can use a square piece of glass sliconed in place to plug the holes, but I also think it would be easier and reversible if you just used the bulkheads with plugs. If you're running sand in the tank, it should cover the bulkheads no problem.

@UncommonSense may be able to provide additional ideas.

 

[UncommonSense]

I'm thinking a 3/8" thick piece overlapping the holes by 1" in any direction should work. Anyone think this is a bad idea?

This will work! Though, I’d give it 18-21 days of curing minimum before use if you go this route… silicone cures very slowly in glass laminations!

You’d also want to to be careful not to press the new 10mm glass pane too tight against the tank bottom; the consequence would be a seam starved of silicone, and glass panes too close together to get a wire or razor in-between if you ever want to remove this glass later!

The quick and easy route is bulkheads, these can always be converted into a closed loop later, or just left as-is!

 

[FullSend]

Turns out one of the holes is less than half an inch from the seam holding the tank together.

Guess I'll be going bulkheads after all...

 

[UncommonSense]

less than half an inch from the seam holding the tank together.

This is a bit concerning…. A 4’ 120g should be 10mm glass… 10mm has a minimum hole rim to pane edge measurement of ~.592”, to meet ASTM c1048… (tempered glass structural requirements; 1.5x glass thickness for the distance between hole rim, and pane edge is dead minimum, 2x glass thickness once you get to 19mm+ glass…)

 

[Kooma]

Nothing more than personal preference,
I'm confident I could remove the glass if I wanted. I'm also planning to drill one of the sides for returns and a new overflow.

Make sure it’s not tempered.

I’d also just put a bulkhead and cap them with a valve if it were me.

 

[FullSend]

This is a bit concerning…. A 4’ 120g should be 10mm glass… 10mm has a minimum hole rim to pane edge measurement of ~.592”, to meet ASTM c1048… (tempered glass structural requirements; 1.5x glass thickness for the distance between hole rim, and pane edge is dead minimum, 2x glass thickness once you get to 19mm+ glass…)

Good to know! New concern, I had assumed (...) the bottom was .5", it's not. It's 3/8" non-tempered bottom. The hole is ~1.75" diameter and ~1.25" from the edge of the pane (.5" from the silicone inside the tank).

I've triple checked the bottom pane with sunglasses and a phone screen. Side-by-side, I can see streaking in a labeled tempered bottom for a 40B. I'm not seeing anything on the 120g.

Hence, the other thread if this thing was really built to last, what would it look like?

 

[FullSend]

Turns out one of the holes is less than half an inch from the seam holding the tank together.

Guess I'll be going bulkheads after all...

~.5" from the silicone inside of the tank

~1.25" from the edge of the pane to edge of hole assuming the bottom pane extends under the side panes to the trim

 

[UncommonSense]

and ~1.25" from the edge of the pane

Oh! This is fine then! Even if bottom pane is 1/2”, that hole could be as close as 3/4” rim-to-edge spacing! (Rimmed tanks have the bottom pane under the vertical panes, not inside them like a rimless tank!)

Nevermind!

Hence, the other thread if this thing was really built to last, what would it look like?

It would probably look like my current extensive glass reinforcement project, less the Red Sea tank!

Build Thread - The FrankenReefer 450

Well, the time has finally come to start documenting the build process of this abomination… Backstory (abridged): I had taken a few years off the hobby, letting my tanks sit idle. I already had a 180g drilled and sumped freshwater tank, plus a little 35G hexagon saltwater tank… but I knew I...

www.reef2reef.com

 

[FullSend]

Oh! This is fine then! Even if bottom pane is 1/2”, that hole could be as close as 3/4” rim-to-edge spacing! (Rimmed tanks have the bottom pane under the vertical panes, not inside them like a rimless tank!)

Nevermind!



It would probably look like my current extensive glass reinforcement project, less the Red Sea tank!

Build Thread - The FrankenReefer 450

Well, the time has finally come to start documenting the build process of this abomination… Backstory (abridged): I had taken a few years off the hobby, letting my tanks sit idle. I already had a 180g drilled and sumped freshwater tank, plus a little 35G hexagon saltwater tank… but I knew I...

www.reef2reef.com

You're actually living my thoughts right now. I'm seeing a ton of used tanks with issues. Which brings up this tank. Maybe it's a poorly built 2' deep tank, but it's probably a good 18" deep tank and an amazing 1' deep 60 gallon tank. I'd be all about a 4'x2'x1' aquarium.