Rebuilding Red Sea 900 XXXL rebuild plan and advise.

[Sushibar]

I am in the process of repairing a 900 xxxl that has a cracked bottom pain.

I have removed the overflow box and metric bulkheads so I can actually measure for the replacement glass. I will be installing the new glass on top of the broken bottom.

Now that the overflow box is out I’m really thinking about drilling the back wall and putting a Reef Savvy Ghost Overflow in.

I’m question is a structural one. The tank is rimless and has 3/4” glass. Wouldn’t any deflection from pressure put strain on the rear glass to the point that it’s looking for “a week spot”? I know first hand that their will be a slight bit of deflection on the front pain when it’s full of water. I’m concerned it may be a issue if I drill the rear.

Im thinking it may be a smart to build the bottom of the new external overflow in a way that addresses back wall deflection.

Anyone have a rimless with a external overflow? Or should I just trim off 1/2” of the original internal overflow and reinstall it?

 

[nereefpat]

Plenty of rimless tanks have rear external overflows. That shouldn't be a problem as long as you can safely plan and drill the back panel.

I'm not sure about adding the new panel on top of the old cracked one. Rimless tanks are put together so that the sides rest on top of the bottom panel, rather than floating like a rimmed tank. I'm not saying you can't, but it worries me a bit. It would probably be better to remove the bottom panel and install the new one in its place.

Let's see if we can some free advice from @Joe Glass Cages

 

[Sushibar]

This tank is built with the bottom inside of the walls.
Drilling is not a problem at all for me.

I’m just concerned that the overflow box is a structural component of a rimless tank that’s drilled.

 

[Joe Glass Cages]

Plenty of rimless tanks have rear external overflows. That shouldn't be a problem as long as you can safely plan and drill the back panel.

I'm not sure about adding the new panel on top of the old cracked one. Rimless tanks are put together so that the sides rest on top of the bottom panel, rather than floating like a rimmed tank. I'm not saying you can't, but it worries me a bit. It would probably be better to remove the bottom panel and install the new one in its place.

Let's see if we can some free advice from @Joe Glass Cages

ouch. Don't like seeing any tank with a crack. yuck.

overflow question. for sure. external and internal. Not sure exactly what type you are thinking. the Reef Savvy one should work just fine. Make sure the glass is not tempered.

Repairing a cracked tank. sure it can be done. I looked at the pictures posted and couldn't find a crack would like to see the damage prior to offering any suggesting. is that possible?

 

[Sushibar]

ouch. Don't like seeing any tank with a crack. yuck.

overflow question. for sure. external and internal. Not sure exactly what type you are thinking. the Reef Savvy one should work just fine. Make sure the glass is not tempered.

Repairing a cracked tank. sure it can be done. I looked at the pictures posted and couldn't find a crack would like to see the damage prior to offering any suggesting. is that possible?

I was planning on installing a 1/2” piece of glass that is cut leaving 1/8” around the perimeter. Then after that cures install silicone around the perimeter sealing the new bottom to the existing walls. After that either drill the bottom for new bulkheads or install a 24” Reaf Savvy Ghost Overflow.

I appreciate any professional input.
Robert

 

[Sushibar]

I also can’t stand looking at the crack. I keep it covered so I don’t have to see it.
I’m also planning on a piece of Starboard on the bottom. It will be a bare bottom tank.