Fixing Cracked Glass - Is It Possible?

[tanglovers]

Hi All,

I was cleaning up a used tank that I was planning on using as a frag tank and when I removed the silicolned in stand pipe I found a crack. Not sure if I caused it or it was like this. I have attached a picture to show what I am dealing with. The hole is a 1" hole and it is about 2.5" from the edge of the tank or seam. It is on the bottom of the tank. The crack appears to go the full distance from the hole to the edge.

My questions:

Is it possible to fix this crack and have the tank still be reliable? How does one do this? Would I need to plug the hole in order to fix it?

I was planning on drilling a 1.75" hole so I could run a 1" bulkhead. Would it be best to fix this spot and drill the tank elsewhere or can I drill around it with the crack to make a larger hole then fix the crack? I have drilled numerous glass tanks but never making one hole larger and never with an existing crack.

Any advice or is this tank trash?

Scott

 

[Qwiv]

Nope. Remove and replace.

 

[kgross]

The best solution is to remove the cracked piece and replace it with a new one. But you should be able to put a glass patch over the crack and drill the old hole out larger and a new hole in the new glass. You will have to make sure you silicone the patch in very well, because when you tighten down the bulkhead you could crack the glass even more.

Kim

 

[ycrazyy]

Remove and replace, no question. I wouldn't mess around with patches or anything of the like. Once a piece of glass cracks, it does not take much for the crack to run in different directions. With tanks having so much pressure on the glass, I wouldn't trust it.

 

[DirtinLa]

I know this is a really old thread but its my exact problem...

Glass frag tank 24 x 24 x 12 with a stand pipe... 1 crack running from stand pipe hole to the edge.

guy said no leaks that he knew of... well it leaks... got it for nothing so no biggie there... there maybe 2 drops of water accumlation after putting in 2 to 3 inches of water...

This thing doesn't have to be pretty!

Here is my question... since it's just a frag tank and may only have 10" of water in it, 40 gallons 320 pounds! I was going to just silicone over the crack and see if that will hold? It's drying right now with the new silicone.

I really think I'm wasting my time there LOL.

If not my next option was I have a thick piece of plexiglass that I can cut

24 x 24 and just silicone it over the existing panel???

all repairs I find on you tube says to just glue a piece of glass directly over the crack but I didn't want to use glass cause I don't have a glass hole saw?

I do have a hole saw that I can drill thru the acrylic though?

Thoughts and suggestions please? BTW the existing glass is appox 6mm or 1/4"

Thanx in advance as always!!!

-=Fred=-

 

[sleepydoc]

Yes, you are wasting your time. Same problem, same answer. If you have the tank in a place where you don't mind 40 gallons of water flooding when it fails, and you have livestock you don't mind loosing when it fails, and you have pumps and other equipment you don't mind getting trashed when it fails, go ahead and try patching it.

silicone does not bond to acrylic. If you want to try patching, you need to use glass.

 

[uncleof6]

I know this is a really old thread but its my exact problem...

Glass frag tank 24 x 24 x 12 with a stand pipe... 1 crack running from stand pipe hole to the edge.

guy said no leaks that he knew of... well it leaks... got it for nothing so no biggie there... there maybe 2 drops of water accumlation after putting in 2 to 3 inches of water...

This thing doesn't have to be pretty!

Here is my question... since it's just a frag tank and may only have 10" of water in it, 40 gallons 320 pounds! I was going to just silicone over the crack and see if that will hold? It's drying right now with the new silicone.

I really think I'm wasting my time there LOL.

If not my next option was I have a thick piece of plexiglass that I can cut

24 x 24 and just silicone it over the existing panel???

all repairs I find on you tube says to just glue a piece of glass directly over the crack but I didn't want to use glass cause I don't have a glass hole saw?

I do have a hole saw that I can drill thru the acrylic though?

Thoughts and suggestions please? BTW the existing glass is appox 6mm or 1/4"

Thanx in advance as always!!!

-=Fred=-

Wasting your time if you use either acrylic or glass, and try to patch it. Only solution is to replace the broken panel. It would be cheaper and safer to replace the tank. 30 gallon tanks are dirt cheap. Next time, don't haul away someone else's garbage unless they pay you.

 

[DirtinLa]

LOL it's a whole frag tank setup two side by side 24 x 24 tanks with sump skimer and everything...

that is great info that acrylic won't stick to silicone cause I was certainly going to try it...

LOL

I did meet a glass guy today so I may just be replacing the whole piece

Thanx everyone

-=Fred=-

 

[stingeragent]

From what I've always heard if you replace a single glass pane in a tank your supposed to resilicone the whole thing as the new won't bond to the old. That's just what I've heard. IMHO your are better off just buying a new tank as small as it is. If it was a big tank that was gonna cost thousands to replace I could see fixing a pane, but on a 2x2 tank, it isn't worth the risk.

 

[uncleof6]

From what I've always heard if you replace a single glass pane in a tank your supposed to resilicone the whole thing as the new won't bond to the old. That's just what I've heard. IMHO your are better off just buying a new tank as small as it is. If it was a big tank that was gonna cost thousands to replace I could see fixing a pane, but on a 2x2 tank, it isn't worth the risk.

Correct. And yes, OP would be better off not wasting the time and money to repair. Just replace the tank(s).

 

[NanoReefWanabe]

in a case like this single panels can easily be removed and replaced without taking the whole tank apart…i use the term easily loosely though…as it is no easy task to remove all the silicone etc from the glass and to remove it without breaking the rest of the panels…that aside…once the tanks free of silicone in all the interior corners and from along the edge you are replacing, you can run a new bead of silicone around the missing panel and install the new glass…once the glass is set you can run a new bead all the way around the interior of the tank to reseal it entirely…good as almost new…tonnes of work for such small and in this case very cheap tank...

 

[Martini5788]

Petco starts their dollar gallon sale today.... Hth

 

[South City]

If its the bottom pane of glass, I've heard of people laying down a whole new pane of glass over top of the cracked one and sealing it. If it's the side, I'd probably just head to Petco and buy a new 30 gallon tank for $30 rather than trying to mess with replacing a glass panel.

 

[NanoReefWanabe]

If its the bottom pane of glass, I've heard of people laying down a whole new pane of glass over top of the cracked one and sealing it. If it's the side, I'd probably just head to Petco and buy a new 30 gallon tank for $30 rather than trying to mess with replacing a glass panel.

i don't know how one would go about doing this, without first removing the entire inner seal of the tank and then super cleaning the bottom of the tank so as to get a good bond to it and side panels, then running a new inner seal around the entire interior of the tank"¦the glass would have to be an exact fit and be placed in there before the silicone skinned over, ith little to no wiggle room to panel in past the top trim"¦

for that matter unless the top trim is removed the is little to no hope of replacing the bottom panel either..

 

[uncleof6]

If its the bottom pane of glass, I've heard of people laying down a whole new pane of glass over top of the cracked one and sealing it. If it's the side, I'd probably just head to Petco and buy a new 30 gallon tank for $30 rather than trying to mess with replacing a glass panel.

Laminating a pane of glass over the broken pain will be just as weak as the original broken pane. Laminating glass together, because silicone is flexible, does not add any strength at all. It would be a false sense of security. Remove and replace is the only repair that can be trusted, and it is honestly not worth the effort on small little tanks like this.

 

[DirtinLa]

I hear everyone about such a small tank But this is one tank that matches exactly a side by side, sitting on a stand, 2 tank system... bottom drilled.

so there is two tanks preplumbed 24 x 24 x 12

I'll try and post pics later...

I would like to add this is a behind the scenes frag tank and not a display tank

I have added silicone (aquarium grade) pasted on the inside and outside of the crack since friday. properly dressed and cleaned....

I'll water test tonight...

LOL OUTSIDE

Question... if acrylic won't seal to silicone than my thoughts of replacing that bottom piece with plexiglass won't work because it will not seal to glass?????

as far as just buying a new tank 24 x 24 x 12 it's NOT a standard size and as such will not fit onto this custom tank set up. I would have to order one bottom drilled

Thanx everyone for your responses

 

[Martini5788]

Maybe you could post pictures of the entire setup, both tanks, so someone could help you more. If you must have a tank that is so specific then I would just replace the bottom plane of glass, drill it, and be done with it.

 

[DirtinLa]

 

[DirtinLa]

 

[NanoReefWanabe]

yeah i would not trust that repair…looks like the tanks sits on top of the bottom rather then being wrapper around it, and there doesn't appear to be any trim on the bottom either…this is pretty much the easiest remove and replace panel job you could have…cut the bottom off, cut out the entire inner seal (leave sides together, be careful not to cut between the sides) apply bead of silicone drop tank on panel, and reseal inside and you are done…

all that said removing silicone residue is no easy task….buy a 100 pack of single edge razors, a bottle of acetone, a bottle of isopropyl alcohol, a tube of neosporin, a box of bandaids, a 6 pack of paper towel rolls, and 3 tubes of RTV103…piece of cake…oh and set aside the entire weekend, and then the following weekend as well to get the job done properly. FYI it will take about 8 minutes to put the new panel and inner seal back in, the rest of the time will be properly cleaning the glass.