Tank bottom hairline crack solutions, brainstorming please

[CWO4GUNNER]

OK new topic how to deal with a slow leak crack on the button of a 225 tank starting with the least expensive and most simplest?
OK Ill start- Throw the tank away LOL.
But seriously I have the tank outside for repair and testing so I'm going to build a new stand and put off refinishing the original stand and focus on a long lasting repair. So please any and all comments on what you would do, try, pay, or have experienced in bottom tank glass repair or patching.

 

[rocker92]

i would say replace the tank or the bottom,i wouldnt feel secure with just some silicone on the bottom, why? because if the pressure makes the crack bigger... you are SOL! lol

 

[kyryah]

I would do what I did - find a tank for cheap that is the right dimensions and has thick enough glass for one pane to fit the bottom. Destroy said tank to remove the glass pane, get it cut to fit (costs $2-5 here to have it cut) and replace the bottom.

I got a 150 for free that had a broken bottom, and I am using a 75 gallon that cost $25 to fix it.

Kristina

 

[CWO4GUNNER]

Hay good start and thanks. Ironically the silicone on the bottom looks brand new, pro-laid and different in color then the rest of the tank, truly weird. Im thinking that it was either a bad effort on the owner to do a repair or the glass was already replaced once and the bad stand caused both the original and replacement to crack.

But your right, silicone on the crack is not the answer without added structural support to the glass.

Remember I have nothing more to lose in trying a repair and standing test outside. heck I may even put my koi in the tank outside if the fix holds up for two weeks until next spring, that should be test enough.
So please more bold fix ideas...

 

[CWO4GUNNER]

I would do what I did - find a tank for cheap that is the right dimensions and has thick enough glass for one pane to fit the bottom. Destroy said tank to remove the glass pane, get it cut to fit (costs $2-5 here to have it cut) and replace the bottom.

I got a 150 for free that had a broken bottom, and I am using a 75 gallon that cost $25 to fix it.

Kristina

Good one kyryah. I think this is 1/2 inch so I may even research a new or remnant replacement panel if I cant find a broken one. Question, wasn't your fix a side panel and there was some concern over the use of tempered glass on the bottom I cant remember why?

Also how hard was it to dig out around the frame and slip in the new glass? Did you have to crack it up piece by piece or did you try and pull it out whole? I'm worried that a 6ft section will not clear the center top brace which can be removed also I suppose, really thick.

Keep the ideas coming I need your thoughts to inspire a DIY solution.

 

[kyryah]

This is a different tank, and the glass used to fix it is not tempered.

I took the top rim (bottom was already missing) off the 75 gallon and cut all the seams apart. The 75 was 48L X 12W X 31H, so I have two panels of glass that are 48L X 31H and 1/2 inch thick. (I am actually going to use the bottom and side pieces to make a little 12" X 12" rimless cube.)

The 150 was turned upside down, and I am cutting the rim from the bottom. Once that is done, the replacement glass will be siliconed in place with the edges overlapping the edges of the sides. You want the sides of the tank to be sitting on the bottom piece when all is said and done.

Once the new bottom is glued in place, I will replace the rim and the whole inside will be resiliconed.

The most important thing is to remove ALL the old silicone and clean the edges with denatured alcohol before gluing the new bottom in and before resiliconing.

(Also, that leaves me with an extra 48" X 31" pane of half inch glass. I happen to have a 48" X 22" 80 gallon tank that my husband and his brother cracked the bottom of when we moved......)

Kristina

 

[geekboy]

Probably a ridiculous idea, but I find myself wondering if it would be possible to add a layer of fiberglass inside on the bottom. It works for boats and water tanks.

 

[chefjamesscott]

did not read the posts, but here is what I would do

Flip the tank upside down, use a expoxy like j b weld and trace the crack completely, making sure to overlap at least 1/2 inch on each side of the crack. Then I would apply about 5 coats of marine grade fiberglass resin and let it completely cure. Then I would turn the tank back over and repeat the process.

For extra safety you could paste a panel of glass large enough to go 4 inches past the crack all around. What the heck, no one will see the bottom anyways.

In the end that this fix don't work, you could always have a glassier redo the bottom.

My wife's grandfather who is a fix it wiz, actually fixed a cracked engine block with jb weld and staples he manufactured.

 

[CWO4GUNNER]

The 150 was turned upside down, and I am cutting the rim from the bottom. Once that is done, the replacement glass will be siliconed in place with the edges overlapping the edges of the sides. You want the sides of the tank to be sitting on the bottom piece when all is said and done.

Once the new bottom is glued in place, I will replace the rim and the whole inside will be resiliconed.

The most important thing is to remove ALL the old silicone and clean the edges with denatured alcohol before gluing the new bottom in and before resiliconing.
Kristina

So your going to repair the 150? How did you remove the frame when you say cut do you mean brake apart or remove intact for replacement? Also what size is your 150 bottom replacement glass? where will you get your replacement glass and what type of glass will you use/need, tempered, non tempered?

Also when you say overlapping the edges you mean on top of and flush with the outer glass panes right?

Are you starting the 150 soon or will it be a while, I'm interested in your success in removing that bottom which actually when you think about it in so far as stability is concerned with all four sides remaining glued the bottom panel seems to be the easiest to replace since the rest of the aquarium remains rock solid as a platform to work on. The only concern is that it remains square and the glass is cut precise. I cant imagine what a piece that size will cost let alone my piece 24X72 $$.

Please let me know what you find out about your 150 repair, problems & solutions.

 

[CWO4GUNNER]

did not read the posts, but here is what I would do

Flip the tank upside down, use a epoxy like j b weld and trace the crack completely, making sure to overlap at least 1/2 inch on each side of the crack. Then I would apply about 5 coats of marine grade fiberglass resin and let it completely cure. Then I would turn the tank back over and repeat the process.

For extra safety you could paste a panel of glass large enough to go 4 inches past the crack all around. What the heck, no one will see the bottom anyways.

In the end that this fix don't work, you could always have a glassier redo the bottom.

My wife's grandfather who is a fix it wiz, actually fixed a cracked engine block with jb weld and staples he manufactured.

I like you idea of trying this as a precursor to having to replace the glass as there is not much lost but maybe something to learn. I think though of I did use fiberglass might it be better to use it exclusively as oppose to mixing layers of JB (which I know is strong) with layers of fiberglass? I almost would like to try the JB alone first. I also like your idea about the pane of glass for structural support over the crack, in fact I was thinking of laying a complete sheet of pexiglass inside the bottom frame picture frame in both dimension and thickness equal to the frame using a complete layer of brushed on silicone sealant, then using a 1 inch layer of polystyrene closed cell foam as a cushion between the tanks now flush bottom and the stand with a reinforced solid closed top (plywood), so that the wight is now evenly supported buy the glass bottom, no more weak center wanting to push down on the crack. Unfortunately there are no perfect 6 long x2 foot sheets of pexi around to cut, only 2x4 foot ($50). Man if only I had a friend that worked at JB weld, I could get the entire bottom filled LOL.