polgara Posted November 19, 2003 Report Share Posted November 19, 2003 Ok one of my tanks had a large crack in the bottom. So I brought a new piece of glass, and siliconed to the bottom, leavin the cracked bit still there, as it would have been mish to get off. What I need to know: Is that all I need, or should I put another strip of glass on the inside on top of crack as well??????? Thx Quote Link to comment Share on other sites More sharing options...
Alan Posted November 19, 2003 Report Share Posted November 19, 2003 Did I read that right??????????? You put the repair glass on the OUTSIDE of the bottom. If so you have boobood The water can still leak out the crack, follow to the outside of the tank, and drain it. YOU MUST PUT THE GLASS ON THE WATER SIDE OF THE CRACK To fix it, cut a big enuff piece of glass to cover all the crack, clean the silicon from the inside beads, use "ACIDIC" cure glue, put a run over the crack, and where the edges of the repair glass will be. Place patch, and do the edges and finish to the side of the tank. Not the prettiest, but a run of black tape along the outside will diguise the appearance. The tank base will now need a bomb to crack it. Alan Quote Link to comment Share on other sites More sharing options...
polgara Posted November 19, 2003 Author Report Share Posted November 19, 2003 :oops: Opps, hmmm ok I will get another piece of glass, and put it in the inside. I knew I should have asked before I did this. Quote Link to comment Share on other sites More sharing options...
Warren Posted November 19, 2003 Report Share Posted November 19, 2003 Hey Alan, The glass has to go on the outside otherwise the force from the sides of the tank will not be transferred properly. Also there is serious risk that the bottom will not be level if the crack has moved a bit. Turn the tank upside down. Silicone needs to be evenly zigzagged across the entire bottom with and extra squirt down the crack. The glass must be really clean first. The new glass is placed on top and moved in a circular pattern under its own weight to even out the high points in the silicone. Once the silicone has fully cured, turn the tank back up the right way. Clean the area along the crack thoroughly. Squirt silicone along the crack to seal the tank. Now you will have a repaired tank with a flat bottom and effectively sealed. Quote Link to comment Share on other sites More sharing options...
Alan Posted November 19, 2003 Report Share Posted November 19, 2003 Are we allowed to disagree on this point Warren? The glue levels off any variation of the crack. The polystyrene underneath level the tank to the base. In time the glue just peels off of the base glass The only ones that I've had probs with have been when I put the patch on the bottom, outside. :oops: I learned from my wicked ways. :evil: Alan Quote Link to comment Share on other sites More sharing options...
Warren Posted November 19, 2003 Report Share Posted November 19, 2003 Are we allowed to disagree on this point Warren? No, go away. The polystyrene underneath level the tank to the base. Zzzzzt, wrong. The polystyrene under a tank does nothing to level the tank to the base. All it does is stop high points like grit or screw heads from cracking the tank bottom. I can show you all the calculations if you like on N/mm² and the compression properties of polystyrene under the weight of a tank, ie solid engineering principals... The new glass is not a patch. It is the new bottom of the tank, ie the same size as the original bottom. This will over double the strength of the bottom of the tank except in the area near the crack. It is a lot more difficult put a new bottom on the inside of a tank, especially if there is already internal bracing. A small patch may work on the inside of the tank but will set up larger stresses in the area near the crack which may cause further cracking in the future. The only way to effect a long-term cure is to replace the bottom glass outright or use a full-size patch on the bottom. In time the glue just peels off of the base glass The glue peels off because the surface wasn't prepared properly. A clean surface has no problems. Lets face it, if there were problems then no tank would hold together for any length of time. I learned from my wicked ways. Maybe you should curb your wicked ways... 8) Quote Link to comment Share on other sites More sharing options...
Alan Posted November 19, 2003 Report Share Posted November 19, 2003 :roll: Quote Link to comment Share on other sites More sharing options...
polgara Posted November 19, 2003 Author Report Share Posted November 19, 2003 Oh dear, what have I done........... Quote Link to comment Share on other sites More sharing options...
Alan Posted November 19, 2003 Report Share Posted November 19, 2003 The polystyrene under a tank does nothing to level the tank to the base. All it does is stop high points like grit or screw heads from cracking the tank bottom and if there is a difference in the broken tank base that you mentioned in your earlier post. It MUST level that off, that was what I meant. It is a lot more difficult put a new bottom on the inside of a tank, especially if there is already internal bracing. Agreed, BUT it can be done The only way to effect a long-term cure is to replace the bottom glass outright or use a full-size patch on the bottom That is what I meant also. Unless it is a small corner crack, then a small patch can be used. The glue peels off because the surface wasn't prepared properly. A clean surface has no problems. Lets face it, if there were problems then no tank would hold together for any length of time. Why risk it????????? I'm still learning Warren. Quote Link to comment Share on other sites More sharing options...
Warren Posted November 19, 2003 Report Share Posted November 19, 2003 We're all still learning Alan... Anyone who professes to know everything about something has a very small mind. Quote Link to comment Share on other sites More sharing options...
Warren Posted November 19, 2003 Report Share Posted November 19, 2003 Yah, just hit 600 posts, well 601 now, I see you just hit 200 Alan Quote Link to comment Share on other sites More sharing options...
Alan Posted November 19, 2003 Report Share Posted November 19, 2003 Now I'll start using my other puta. Get twice as many posts then :lol: Alan Quote Link to comment Share on other sites More sharing options...
Warren Posted November 19, 2003 Report Share Posted November 19, 2003 Jut use one with dual processors??!! 8) Quote Link to comment Share on other sites More sharing options...
Dark Posted November 19, 2003 Report Share Posted November 19, 2003 when the base of my tank cracked i pulled the whole thing apart and stuck it back together again, and got a stand that was definately going to support it, come hell or high water. One of the reasons i did; i have seen tanks where people have repaired them by gluing on another piece of glass - seems fairly acceptable except in one case when they had done it 3 times! with the additional 30mm of glass on the base the tank must have weighed nearly twice its original weight! my 4.5' tank takes two strong people to move it, if it weighed twice as much i'd never get it out the door, but i guess thats only really a problem for bigger tanks, or if you are actually planning on moving them... Other reasoning includes; you have that nice stand and now the base glass is showing above the beading around the edge of the stand - i have enough problems getting the right thickness of polystyrene so that about 30% of the substrate is below the lip of the stand. Basically - a fishtank is a piece of furniture as much as it is anything else, it is good if it looks nice. I was once told by the owner of a deceased petshop (Victoria St, Wgtn) that their tanks had to be resealed every 7 - 10 years. I don't know how true this is with more modern silicate sealers, my local glazier insists that it should never need replacing... If the former is true it can't be that bad to re-build a tank once in a while, although any comments on that are welcomed. Quote Link to comment Share on other sites More sharing options...
Alan Posted November 19, 2003 Report Share Posted November 19, 2003 you trying to teach ME Warren??????? A bit above my head :roll: Quote Link to comment Share on other sites More sharing options...
Pegasus Posted November 19, 2003 Report Share Posted November 19, 2003 Warren said: Are we allowed to disagree on this point Warren? No, go away. Hopefully this was meant in a kind manner. Quite honestly, if I had to go to the expense of buying a new base.. then adding it to the bottom, plus all the expense and labour, it would be just as easy to remove the old base and replace it.. far less unsightly. In the end, it all comes down to what works for the individual, and 'everyone's' views are valued on the forums. Quote Link to comment Share on other sites More sharing options...
Ira Posted November 20, 2003 Report Share Posted November 20, 2003 I think I'd probably do the same. If it's a large tank I'd take it to someone that knows what they're doing to replace the bottom. A small tank I'd probably try fixing it myself because it wouldn't be too expensive to replace it if I totally blow it. Quote Link to comment Share on other sites More sharing options...
Caryl Posted November 20, 2003 Report Share Posted November 20, 2003 We are overdue for a re-seal then as I believe our main tank has been set up for almost 14 years, plus we used it as a wardrobe for a couple of years before that. Quote Link to comment Share on other sites More sharing options...
Warren Posted November 20, 2003 Report Share Posted November 20, 2003 Warren said: Hopefully this was meant in a kind manner. Hi Bill, I should think by now everyone would know me enough so that humour can be used without question. I was after all quoting a fairly well know line from the 'Light and Tasty' add. Hi Caryl, My oldest tank (the 8 foot one - yes that one) is 22 years, never been reglued. It shows no signs of letting go either. Quote Link to comment Share on other sites More sharing options...
Pegasus Posted November 20, 2003 Report Share Posted November 20, 2003 Must watch the ad's more often Quote Link to comment Share on other sites More sharing options...
Warren Posted November 20, 2003 Report Share Posted November 20, 2003 Yeah, spend lots of time in front of the TV. I know I spend far too long in front of it. Oh well, its an old TV now, - maybe it'll blow up soon and solve the problem. Quote Link to comment Share on other sites More sharing options...
Alan Posted November 20, 2003 Report Share Posted November 20, 2003 Warren, were you pokin' me in the eye? Alan Quote Link to comment Share on other sites More sharing options...
Paul Posted November 20, 2003 Report Share Posted November 20, 2003 Ive been known to add strips of glass on the inside over cracks with generous use of silicone, This tends to be only on smaller tanks ie under 3ft and not deep ie under 15in depth. I consider this to be only a very temporary measure. I have never left a cracked bottom panel in place and glued a whole new bottom in/out (depends who we talk to on this one ) I will just remove the cracked sheet and replace the whole thing. Replacing the whole sheet is the best option it allows you to clear away any trace of the old silicone and have complete clean joints once again. You then must work out why the sheet cracked in the first place! I have had and built many hundreds of aquariums over the years and I think I could count the number of cracked tanks that I have had set up using my fingers. Quote Link to comment Share on other sites More sharing options...
Dark Posted November 24, 2003 Report Share Posted November 24, 2003 Yeah, spend lots of time in front of the TV. I know I spend far too long in front of it. Oh well, its an old TV now, - maybe it'll blow up soon and solve the problem. Then you can make it into a funky looking fishtank, hook the front panel controls of the TV (assuming it is old enough to have knobs or sliders like mine) up to your pumps lighting and thermo, take out tube and electrics and stick in a tank!! i've converted the old mac classic computers to tanks before but recently saw one where the, somewhat enthusiastic, individual had gone to the trouble of cutting the front off the monitor tube and ensuring that it sat in the same place when attached to the tank - to retain the curved look instead of the flat glass... what will people do when there are no more tube TVs and we only have LCD and Plasma screens? *sigh* Quote Link to comment Share on other sites More sharing options...
Ira Posted November 24, 2003 Report Share Posted November 24, 2003 You can still have an in wall tank with the surround from the plasma screen around it. Quote Link to comment Share on other sites More sharing options...
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