msc0433 Posted May 20, 2012 Report Share Posted May 20, 2012 Hi people looking at afew tanks at moment that are 8 foot long. They are only 40 cm high and 2 foot wide. They are made of 6mm glass sides and was wondering if a large fronty were to hit the glass in fright would 6mm be thick enough to not break Thanks. Mark Link to comment Share on other sites More sharing options...
liljohn_83 Posted May 20, 2012 Report Share Posted May 20, 2012 6 mm ? thats a bit shy i think 8 ft tanks should be 10-12 mm Link to comment Share on other sites More sharing options...
msc0433 Posted May 20, 2012 Author Report Share Posted May 20, 2012 Even if height is only 40cm? Link to comment Share on other sites More sharing options...
liljohn_83 Posted May 20, 2012 Report Share Posted May 20, 2012 not sure on the height factor vs thicknes ive kept a sml colony of 4 fronts 20 -25 cm in a 6 ft tank that was 6 mm thick no problem but i personaly wouldent touch a 8 ft thats 6 mm just sounds scary too long and to mutch water volume in my opinion Link to comment Share on other sites More sharing options...
msc0433 Posted May 20, 2012 Author Report Share Posted May 20, 2012 Thanks bud might think twice. They are a good price but I don't want water everywhere and dead fish. Might have to spend the extra $$$$ Link to comment Share on other sites More sharing options...
Grimace Posted May 20, 2012 Report Share Posted May 20, 2012 So long as it is braced correctly you could have a 17ft tank with 6mm sides at just 40cm height. The height is what determines the thickness required not the length Although I would personally prefer it to be minimum of 8mm glass for 40cm high, 10mm min for 60cm high and 12mm minimum for 900 etc etc. Link to comment Share on other sites More sharing options...
ozmo Posted May 20, 2012 Report Share Posted May 20, 2012 Nothing less than 12mm on anything longer than 6ft IMO. Link to comment Share on other sites More sharing options...
fancygoldfish Posted May 20, 2012 Report Share Posted May 20, 2012 i wouldn't risk my fish in anything less than 10-12mm. Link to comment Share on other sites More sharing options...
DeadFishFloating Posted May 20, 2012 Report Share Posted May 20, 2012 Have to agree, 6mm for an 8 footer sounds dangerous. Link to comment Share on other sites More sharing options...
cram Posted May 20, 2012 Report Share Posted May 20, 2012 The primary concern for glass thickness is water height - 6 mm is fine for 40cm deep. Secondary is the length of the pane and bowing (leading to cracking). This can be overcome with sufficiant bracing (rails and cross braces). so an 8 ft long 40 cm high tank is fine in 6mm glass as long as it is braced properly. As for your fish and 6 mm glass - if you were to put him in a 4x2x18 tank with 10mm base and 6 mm sides would you be happy? if so, then an 8 fter with the same glass is no different. Link to comment Share on other sites More sharing options...
jubes Posted May 20, 2012 Report Share Posted May 20, 2012 In my personal experiences in life. Spend the money and it will last. Some bargains aren't always bargains. I wouldn't touch this 8ft Link to comment Share on other sites More sharing options...
vickisam01 Posted May 20, 2012 Report Share Posted May 20, 2012 I would buy it depending on bracing. If you arent interested let me know where it is? Link to comment Share on other sites More sharing options...
blade87 Posted May 20, 2012 Report Share Posted May 20, 2012 Wouldnt trust it i had a6x2.5x2.5 16mm glass crack strate thru bracing lid lips and strate down the centre wouldnt trust it at all Link to comment Share on other sites More sharing options...
DeadFishFloating Posted May 20, 2012 Report Share Posted May 20, 2012 lotta pressure on an 8 foot and you would only have to drop a small rock............ in theory 6mm may be thick enuf but in practise, IMHO you want at least 10mm Link to comment Share on other sites More sharing options...
pony-tail Posted May 21, 2012 Report Share Posted May 21, 2012 I would not buy it - Although 6mm glass is plenty for a tank 400mm deep there is the factor of the length . At 8 foot the glass will try to bow out putting a lot of strain on the glue joints . If they stretch or fail the tank will fail catastrophically . An 8ft x 400mm 6mm piece of glass will bow substantially just under it's own weight if you pick it up flat by the 2 ends . Even if it is properly braced , as the glue ages and weakens it may separate , there is a lot of stresses involved in a tank that length . If it fails it will make a VERY BIG MESS . Don't chance it . Link to comment Share on other sites More sharing options...
Supercobwe Posted May 21, 2012 Report Share Posted May 21, 2012 Have to agree, 6mm for an 8 footer sounds dangerous. x2.........accident waiting to happen. Link to comment Share on other sites More sharing options...
Defzkon Posted May 21, 2012 Report Share Posted May 21, 2012 8mm glass for 40cm high, 10mm min for 60cm high and 12mm minimum for 900 etc etc. Dennison will only go 76cm/2.5foot with 12mm, 90cm/3foot is 15mm. Link to comment Share on other sites More sharing options...
Hellbound Posted May 21, 2012 Report Share Posted May 21, 2012 just because it can be done does not meant it should be done. Link to comment Share on other sites More sharing options...
CrayonBox Posted May 21, 2012 Report Share Posted May 21, 2012 it will hold water fine if the glue doesnt fail and if the glass doesnt bow, all it will take is someone to tap the glass and it will smash, thats way to much pressure for 6mm glass Link to comment Share on other sites More sharing options...
cram Posted May 21, 2012 Report Share Posted May 21, 2012 it will hold water fine if the glue doesnt fail and if the glass doesnt bow, all it will take is someone to tap the glass and it will smash, thats way to much pressure for 6mm glass The pressure of water at 40 cm depth is the same regardless of how long/wide the tank is - i.e. the pressure at the bottom of your 2 ft tank is the same as a swimming pool at 40cm depth. 6 mm will hold up that pressure. The deflection of 8 ft of glass is whats important - the same as in any tank which requires bracing. Properly braced, there is no difference between this tank and a 4x2x18 in terms of glass thickness v safety factor. 6 mm is fine, but yes 8 mm is stronger (and heavier and more costly) and then so is 10 and so on.... have a play with this: Rivermuds Glass and Acrylic Calculator (it lives) food for thought: so according to the wizbang calculator, an 8x2x16 with 6mm side has a safety factor of around 2.5. Interestingly, a 6x2x2 with the same safety factor (2.5) requires 10.45mm sides (according to the calculator). The failure of bracing and rails etc for teh 8 ft is the same as teh 6fter, and every other tank that is braced. However, in addition to having a higher saftey factor, a tank built of thicker glass would also be better able to withstand stresses associated with handling, uneven stands etc Link to comment Share on other sites More sharing options...
DeadFishFloating Posted May 21, 2012 Report Share Posted May 21, 2012 a tank built of thicker glass would also be better able to withstand stresses associated with handling, uneven stands etc and here in lies my concern over the years I have given tanks the odd knock/tap or chip and ya want it to be able to hold up even with a bit of battle damage! Link to comment Share on other sites More sharing options...
