crack repair

[Shane Whitaker]

Brand new to your forum, just found out it existed. I'm told this is the place to go for information about tank repair.
I just bought a used Red Sea 135g aquarium and realized just before I set it up that we cracked the bottom glass moving it. The crack is about 4 inches long and is, as of yet, not full thickness. In other words, I can see the crack but you can not feel the crack from the inside and if you shine a light on it, it appears as though the inside surface is intact. The stand has a solid top with 1/2 foam rubber mat under the entire tank, so the glass sits right on the foam rubber.
Here is my idea, I'd like to know if those with experience here like or dislike my plan or have a better plan. The bottom of this tank is recessed by 1/4" The inside dimensions of the recessed area is 19" X 46". There is a 1 and 1/2" frame all the way around this recessed area. My plan is to buy a piece of glass 18 3/4" X 45 3/4" X 1/4" and silicone it into the recessed area on top of the existing bottom. Then buy 2 pieces of glass 19 1/2" X 23 1/4" X 1/4" and silicone those over the top of the first piece. Wait 48 hours and set it up.
I don't think I can feasibly totally replace the bottom glass mainly due to the weight of the tank and lack of help to keep moving it around, but if someone has a reasonable way to do that, I'm willing to do what I can.
Thank you in advance for the help

 

[Yoimbrian]

I'll let experts chime in on repair, as I've never done it.

My two cents though, id seriously look at the cost of replacing the tank vs the potential water damage.

 

[skjl47]

Hello; I am not an expert but have done the sort of thing you contemplate. Not with a tank as large as you have however.
The finished project can be unsightly but at the bottom likely can be hidden.
Best pointers I can think of are to make sure the surfaces are dry and clean. I sometimes hang an incandescent bulb light in a tank to be siliconed for a while. This should help dry out any moisture in the crack and around the tank seams.
Another is to get as much tiny bits of grit, sand and all out as you can. I use a shop vac. Also a tack cloth will pick up a lot of stuff.

Think it out a few times. Don't get too focused on the repair and mess up some other aspect such as having the repair too thick so as to not sit on a stand properly.

Last thought. This sort of repair can work and hold up well. The "BUT" is that you find out the hard way if it fails. Not any way to know ahead of time. Might fail right away or weeks to months later. If it is to be set up in a basement with a floor drain then you have a whole lot less to worry about. On a wood floor in a house a failure can get to be a major expense.

Good luck

 

[duanes]

I silicone a pane of glass on top of the crack, large enough to stretch beyond where it might extend, and if possible one on the other side the same way.
Below is a repair I did on a 150 gal, about years ago, and it still holds water.


I always remove old silicone

 

[Shane Whitaker]

Thank you for your replies. I'm ridiculously OCD so I've thought this over a couple hindered times and I think the physics works. Problem is all the things I haven't thought to factor into it. I siliconed in a piece of glass the size of the entire bottom of the tank. I'm filling it up with just plain water for now so I can see the bottom the whole time. My worry is as skj mentioned, that it might fail months from now when we aren't expecting it.

 

[skjl47]

My worry is as skj mentioned, that it might fail months from now when we aren't expecting it.

Hello; You may be able to relax in stages as time passes. May give your OCD something to focus on for a while. With luck the failure will be a leak and not a total failure. My guess is a big fail will happen sooner.

Good luck and congrats for having the gumption to try.

 

[Bigfishnut]

When you silicone the repair glass, apply the silicone in wavey lines to get full coverage. It will spread and make a uniform layer when you apply pressure. Swipe around the edges with your finger while the silicone is still fluid. This type of repair absolutely works on bottom panels only. If done properly, it will not fail. Put a weight on the repair glass to ensure a good bond with no air bubbles. You really only need one panel on the inside of the tank. The one you plan to add underneath is not necessary.

 

[millerkid519]

Thank you for your replies. I'm ridiculously OCD so I've thought this over a couple hindered times and I think the physics works. Problem is all the things I haven't thought to factor into it. I siliconed in a piece of glass the size of the entire bottom of the tank. I'm filling it up with just plain water for now so I can see the bottom the whole time. My worry is as skj mentioned, that it might fail months from now when we aren't expecting it.

Make it a sump and use it for the side your pump section is on

 

[millerkid519]

When I have done it i have used a half tube of silicone on the inside and half tube on the outside. Don't be worried to use to much because you wont.

 

[millerkid519]

I actually have an old sump with a crack from top to bottom on the front side that I am going to patch and reuse. It will be on the return section with low water line