Patching crack and holes (pics)

[SkinnyPete]

I just got a used 40 gallon breeder tank from a local reefer for free. There was a small crack between two drilled holes on one side of the tank. While moving the tank out of his house, however, the crack grew upwards to the top of the tank. (see pics below)

I'm planning on using this as my sump, so it will not be completely full. I do not need these drilled holes, so I planned to patch them with glass or acrylic. My initial idea was to silicone a piece of acrylic (which I have lying around) to the outside of the tank, covering the two holes and the crack. Then, after it has dried, silicone the holes from the inside to the acrylic and run a bead of silicone up the crack on the inside of the tank. Obviously, I'd test for leaks before I added baffles etc. But, I thought I'd get some opinions. Should this be enough for a crack this size? You can't really tell by the pics, but the crack is really tight. I had to run my fingers along the inside a few times to determine if it goes all the way through (which unfortunately it does).

Any suggestions? Do I need to get a different tank? Thought it was a good deal for FREE.

 

[aznbob]

I would do that but just the opposite. Put the acrylic plate on the inside of the tank so when it's filled with water the pressure pushes it against the tank. The other way around it would be pushed against nothing and would pop out.

 

[malkore]

Honestly I'd replace the entire piece of glass. I work with non-tempered art glass for my stained glass hobby...and if tempered glass is anything like non-tempered, a crack will run wherever it wants to, even with support applied.

The piece of acrylic is gonna have 'flex' to it, and when it starts to bow from the weight, it's gonna run that crack long and likely cause the entire thing to fail.

and it may not happen right away, since temp changes have a big effect on glass shrinking/growing. it could seem fine for a couple days, and then it gets too cool one night, and you wake up to a hundred gallons of wet floor.

 

[DragonForce]

I would use a razor blade to take out the peice and then get a new peice cut and then silicone it back in. Basic DIY skills should be more than enough. Maybe someone can elaborate.

 

[seaham358]

Like they say either replace the broken piece or toss it. Why tak a change just to save a few bucks..

 

[AMANIQU77]

That's dangerous man. Once there's crack, might as well consider that two pieces. With the water volume and stress over time on the glass, no epoxy or acrylic something can stop the inevitable. Good luck however, Recycling is cool.

 

[BillD]

Forget the acrylic. Silicone doesn't stick as well to the acrylic as it does to glass. You can euther replace the glass or cover it with a piece of the same size, and silicone over the crack and holes. Replacing the glass would be the best choice.

 

[Brenden]

I would replace the glass. If you insist on patching I would use a piece of glass instead of acrylic. The silicon will stick better and the glass will not flex like the acrylic and cause uneven pressure on a spot that is already weak.

 

[fishrfreinds]

when i was cleaning my tank outside with friends. One of them thought i woud be funny if the sprayed me with water while my back was turned and i stratled me (it was COLD) and the tank slip and cracked the back sorta like ures. anyway i was going to throw the tank out when my dad said he could fix and sure enough he did. It cost only like 20 bucks for glass and silcone. Just replace that pannel and youll be glad you did. And. its alot easy then patch work. take razor to get the old silcone off. oh and the tank size was 29.

 

[fishrfreinds]

oh somebody all ready took my razor advice.