*yawn*

[Rotaripsnoc]

Fractured tank bottom ...

First time since I've started keeping fish, some 20 years, that I've had a tank fracture on me. The 30 gal we purchased used, half round, 13.5" radius, 28 " tall, bottom split on me tonight. Noticed some water on the floor, and the tank level down 0.5", hoped it was just the filter leaking, but no such luck. The tank was shimmed perfectly level, no major temp changes, guessing it was a fault in the glass, or perhaps weakened by live rock being dropped harder than needed by the previous owner.

At any rate, the glass is 3/8" I believe tempered glass, but I cannot find a stamp on any of the pieces. I'm going to try and replace the bottom of the tank, clean the old silicone off, and bond a new piece to the tank.

Does anyone have anyplace online they can recommend, or have done business with, where one can purchase a half round 27" diameter, 3/8" thick tempered piece of glass ?

I'm going to check around the city where I live at, but I'd likely have to go 80 + miles to procure a piece.

Oh because it was a very slow leak, I siphoned enough out to fill our 10 gal tank and move our figure 8 puffer to it, currently there's a 30 gal filter on a 10 gal tank, but he seems to like it, and there are a few caves he can hide in if he needs to escape the current.

 

[exhumed07]

Wow that sucks. seems to be an issue recently with broken tanks. one thing I can suggest being a construction worker is getting hold of a contractor to get glazers which are glass installers. they may be able to get u into contact with their suppliers. its worth a shot.

 

[FreshyFresh]

The scenario is all to familiar to me.

You mentioned the tank being shimmed. Does this mean the tank stand was shimmed level or the actual tank? I don't think you'd ever want to shim the tank itself.

Check online or your yellow pages for a local glass shop. I've got one fairly close that will cut you any size/shape you give them, with the glass type of your choice. I've never tried to repair an aquarium though.

 

[Rotaripsnoc]

The stand was shimmed, and even after it cracked the tank was perfectly level, I never thought to speak to a construction \ contractor office that's a great idea. I'm probably going to replace it with at least 1/2 " tempered glass, I think the bottom is only 3/8" but maybe a thicker piece will help.

I probably wouldn't bother with the repair if it was a rectangle tank, but this tank is a good 2 feet tall, and half round, it's one of only a few I've seen like it, and I really enjoy it. It's virtually the same as this, but only 30 gal, and it's a plastic hood vs a wooden hood http://www.rjaquatics.com/images/half moon pic jpeg.jpg

 

[exhumed07]

that would be a neat tank to have. i've never seen a tank like that except for custom tanks. I'd probably do what i could to fix it as well. just make sure you work quickly so the new silicone don't skin on you before putting it in place. once it forms a skin it will not adhear to the glass as i am sure you are already aware, but seemed right to mention it. I personally hate working with silicone. sticky nasty crap. if only i was able to use Solonastic NP1. I use that at work in expantion joints in brick and concrete walls as well as concrete decks. anywhere the joint expands/contracts, or heaves. it's great stuff and can be used on glass with 766 primer. but thats the problem. the primer sticks to the glass and the NP1 sticks to the primer. also i'm not sure what the pressure threshold is. also for use in water it requires primer 733 which is an aluminum and concrete primer and a 21 day minimum cure time at 70* and 50% humidity. I looked into all of this stuff with my paludarium build since i have a box of the stuff in the garage. anywho I hope you get the glass that you need and hope it all works out for you. keep us updated.

 

[Rotaripsnoc]

The first place I called locally said they could order and cut tempered glass upto 3/8 " however they asked what I was using it for, and not thinking any thing I told them. They literally freaked out, an Aquarium what ! blah blah blah. I called another place ... we have 1 McDonald, 1 Walmart, and 3 glass shops ... but anyway, I'm just waiting on a quote back for the piece.

The frame looks like it's only attached to the bottom plate of glass, so I thought I would try to use a heat-gun to help detach it. Afterward a straight edge razor to cut between the walls and the bottom. Then to remove the old silicone from the walls and clean the glass. since I will only be bonding 1 piece of glass vs the walls I don't think it will be too difficult. I'm expecting the hardest part to be running a bead of silicone inside the tank to re-enforce the joint.

 

[Thyra]

I am assuming you googled "replacing aquarium glass, but just in case here is one idea I found interesting;

How can I repair the cracked bottom glass of my fish tank ? - Yahoo! Answers

This means you put plexiglass over the bottom without removing the cracked glass.

 

[FreshyFresh]

I think Thyra dug-up the best option. I'd hate to disturb and break the plastic bottom edging, The tank would be a goner then unless you could order new plastic.

 

[Rotaripsnoc]

Thanks Thyra and FF I considered patching it in that manner, however the crack extends into the silicone along one of the walls of the tank. I am also worried that since the glass has already cracked there might be another weak spot that could give way without warning.

If the crack didn't touch the edge of the base, I would definitely patch the tank like this.

I think I can probably remove the plastic undamaged, if not, it doesn't add an structural support to the tank that I can tell, I think it's purpose is to keep the edge from chipping or being bumped in a way that would crack \ damage the glass. I figure if I damage the frame while removing it, I can either print a new one, sand \ shape it slightly to remove any printing ridges, and cast it in a mold to create a frame from, or I can replace the frame with a wooden base, that would do the same thing, but I could stain a deep cherry and varnish so it would be impervious to water \ humidity changes.

I found a few sites online where I can have them cut the desired shape and send it to me, which is probably what I will do simply because they offer it much much cheaper, around $60. The second business got back to me with a quote, and they wanted $210 for 1/2" Tempered glass in the size and shape I would need it.

 

[exhumed07]

well the thing is about using a piece of plexi or acrylic on the bottom like that. the plexi is going to form a solid bottom thats not going to flex just like the glass. all u would really need to do is place that piece on the bottom and then seal around the edge with silicone for water tightness. with the arylic/ plexi option with leaving the original cracked glass in the bottom there would be nothing to worry about i think. thing is it is a bit expensive. I had some pieces cut for me a long time ago for trays to make LED moonlighting. that was 60 bucks for 1/8 inch thick pieces 1/2 inch tall by 2 inch wide by 18 inches long. had 3 of them cut and i put them together. maybe one solid large piece would be better since there is less cutting idk. maybe the arch shape would cost more. but thyra did come across a viable option in my opinion. I thought about doing with seel or aluminum. aluminum would not corode and strenghten the bottom allowing for heavier decor without fear of pressure points crackign the glass. steel would rust but with live plants it may be good for the roots to get alot of iron making red plants really red. i never have done it but have thought about it.

 

[FreshyFresh]

Rotar- I'm pretty sure any tank that's comprised of glass panels siliconed together, relies on the top and bottom plastic rims for structural rigidity.

 

[Rotaripsnoc]

I thought about that too, no one ever see's the bottom of the tank, and the substrate covers it, I wonder if there is a plastic board that could be adhered to a metal plate or something. No more cracks ever !

 

[FreshyFresh]

I had an ancient 10g many years ago that had a slate bottom and chrome metal edging.

 

[exhumed07]

A friend of mine had a 20 gallon like that freshy. he kept his Oscar in it

 

[Rotaripsnoc]

I was looking at options, found slate in my area pretty cheap due to some housing contractors, I'll probably give them a call tomorrow. Also while searching, I remembered watching an episode of how it's made ( How Its Made - Cultured Marble Sinks - YouTube ) , for faux marble counter tops which use epoxy with some dye, I found a few epoxy sellers with products safe for aquarium use. I might have to get some and experiment with it. The base is about 3.5 sq ft, Slate runs $10 a sq ft on average here, the epoxy would be about $5. I could easily build a mold for the epoxy base and cast it in any color, or to look like marble, which the more I think about the more I think would suit this tank.

Slate

• Pro:
  • Classy look
  • Proven tank bottom
  • Impervious to stand warping.
  • Very low expansion \ contraction based on temp
• Con:
  • Could contain micro cracks \ weak spots
  • Minimum thickness of 1.5"
  • Heavy
  • I could not shape or cut the piece

Epoxy

• Pro:
  • Lite weight
  • Can be poured into a mold
  • Can control thickness
  • Can be sanded \ cut \ shaped easily afterward as needed.
• Con:
  • Unknown

 

[Thyra]

Have you considered trying to fill the crack/gap with gorilla glue? Would it be possible to cut cut plexiglass from a pattern to fit inside and run a bead of gorilla glue around all the edges? (Besides gluing the plexiglass down.)

 

[exhumed07]

gorilla glue (at least the stuff i use) seems to foam up and expand a bit, I'm not sure if thats a good idea thyra. but what u are saying is kinda what i thought of. just lay the plexi on top of the broken bottom and then run a good bead of silicone around the edge for water tightness. the best way i could explaine it is liek laying shingles down on your roof over top the old shingles. 2 layers and i would assume even though the bottom pain of glass is cracked that it would still add strength to the whole bottom. you could probably get away with a fairly thin piece. I would recomend going with a piece thick enough to hold the water on it's own but just saying.

 

[Thyra]

I don't think I have ever used the stuff (Gorilla Glue) but I did read the specs on it and it is an epoxy and it says it can fill cracks - are there different kinds of gorilla glue? I never knew epoxy could foam.

 

[exhumed07]

It don't foam like great stuff expanding foam but it does expand a bit which is something that you don't want. id just stick with silicone. its proven and safe