Pies Posted May 10, 2004 Report Share Posted May 10, 2004 OK I can't figure out how to use the thickness calculator. Tank is 2200Lx700Hx850W. I am going to use 12mm glass, this should be OK? For the tank base can I use doubble thickness 12 or 10 mm? If so is it easy to glue the 2 together? The tank will have braces accross the bottom, connecting the bottom to the front, back and sides. The top will have several center braces, larger ones on each end glued from front to back, and then 2 smaller ones 100mm wide accross the top. I might have glued additional strips accross the inside front, and outside back accross the top. Helping strengthen the top and give more glass for the braces to attach too. The tank will only be filled to the 670mm high line. There will be about 200kg or rock, which much displace the water and reduce pressure? Ohhh and there will be holes drilled everywhere (bottom, back and sides). What say you? Pies Quote Link to comment Share on other sites More sharing options...
Warren Posted May 10, 2004 Report Share Posted May 10, 2004 Do you have MS Excel? If so, just use the glass thickness calculator on the top right corner of the page (just click on the link). It takes all the hard work out of it... Quote Link to comment Share on other sites More sharing options...
Warren Posted May 10, 2004 Report Share Posted May 10, 2004 Anything displacing water in a tank does not reduce the pressure. It is not the quantity of water in a tank, it's the height. Height directly relates to pressure. So a tank that's 2200 long and 700 tall needs the same front and back glass thickness if it has 100L or 2000L of water in it if the water level is the same. The only difference is the 2000L tank will be 20x wider. Quote Link to comment Share on other sites More sharing options...
Pies Posted May 12, 2004 Author Report Share Posted May 12, 2004 Thank Warren I see the link from the page. I am still not certain I am reading it correctly. Why doesn't it ask for all 3 paramaters, not just 2 of them? Bottom line, is 12mm OK? Also I am looking at 'dimante' glass for the front and 1 side. This is the SUPER CLEAR glass with no lead in it. Will this be strong enough? Anyone else used the glass? Pies Quote Link to comment Share on other sites More sharing options...
Ira Posted May 12, 2004 Report Share Posted May 12, 2004 Because length and height are the only ones that matter PER SIDE. If you want to check the thickness for the side panels enter the length and height of those side ones. Like for the side ones you'd put in height of 750 and length of 850. Quote Link to comment Share on other sites More sharing options...
Pies Posted May 12, 2004 Author Report Share Posted May 12, 2004 Thanks Ira, that makes more sense to me Now 3 more questions... a. how does the safter factor work? e.g. for a tank of the size I am planing I can only have a saftey factor of 2 for the front and back. is that enough? what is the difference between 2 and 3. b. The base needs to be thicker. Can I have 2 pieces of glass glued together making it double thick? if so 2x 10mm as oposed to 2x 12mm? c. Is the tank of the size I am planing going to be safe at 12mm for the front and back? Or am I going to need thicker glass? ACK! Anyone out there with a tank this size or bigger? Pies Quote Link to comment Share on other sites More sharing options...
Ira Posted May 12, 2004 Report Share Posted May 12, 2004 The safety factor is if it's 2X the glass is strong enough to handle 2 times the force on it. So, if there's a total pressure of 100 lbs pressing out with a given tank it could handle another 100 lbs of force, evenly distributed, before the glass breaks. that's the ideal anyway. As for the rest, I'll let warren answer. Quote Link to comment Share on other sites More sharing options...
Dark Posted May 15, 2004 Report Share Posted May 15, 2004 yo pies, thought you'd never build another tank yourself! Quote Link to comment Share on other sites More sharing options...
Pies Posted May 16, 2004 Author Report Share Posted May 16, 2004 Dark! Nah I am having Peter build it for me. I am not allowed to build another! hahahahahaha. Gonna be a biggie this one... Quote Link to comment Share on other sites More sharing options...
chimera Posted May 21, 2004 Report Share Posted May 21, 2004 A good read to get the basic's from a pro... http://www.austinglass.com.au/aquariums.html A couple of paragraphs taken from this site: Broadly speaking, engineering is the critical factor, not the thickness of the glass. With enough braces you could theoretically build an enormous glass tank from very thin material, but it would not look very attractive. You would need to have vertical braces every few inches and that definitely is not what you want. The pressure on the joins where the sides meet the base increases dramatically with height. If you keep the height to the lowest acceptable, you will reduce the risk of a blow out. This does not mean you cannot have a tall tank, but it does create extra engineering problems As a guide, I recommend the water height should be no more than 500 mm for 6mm glass, 600 mm for 8mm thick glass, 700mm for 10mm etc. As you will probably fill the tank to within 75mm of the top, this still provides for a fairly tall tank with no special requirements. If you are planning a tall tank, say over 700mm, (30") the main things to check thoroughly are glass thickness, cover strips for the corners, and extra bracing where the base meets the sides. Quote Link to comment Share on other sites More sharing options...
Warren Posted May 23, 2004 Report Share Posted May 23, 2004 Not a bad article but it implies the force on the glass is proportional to the weight of the water in the tank. This is not directly true as it's not the weight of the water that effects the force on the glass but the water level. It is possible to make a 10L tank that needs 25mm glass. Alternatively the same 10L could be safely held in a tank made from 3mm glass. It all depends on the shape of the tank. Bracing will help to some degree as stated, but the thickness of the glass still has to be able to withstand the pressure of the unsupported area. The maths (which is really what the term engineering should refer to in this case) still needs to be done to calculate the correct glass thickness. All the bracing is just the support mechanism. The advice on the bracing size seems fairly sound, maybe a little on the light side. The bottom thickness statement is only true if the base is truly level and does not deform at all under the weight of the tank. If it does, then the glass has to be thick enough to support either the full weight or the partial load. This needs to be calculated too. Quote Link to comment Share on other sites More sharing options...
Pies Posted May 23, 2004 Author Report Share Posted May 23, 2004 I find this subjecy so confusing! Any chance of an answer? FINAL CONFIRMED DIMENTIONS - 2140Lx900Wx700H 12mm all around. The base support will be 10mm and will 'insert' inside the tank, thus giving the sides twice the glass to glue too, and making the base 22mm thick (12mm with 10mm on top). The lid will be braced in the sides and center. What say you Warren? Am I safe? I don't understand this 2.2 saftey factor. What we need is 'glass thickness for dummies'. Quote Link to comment Share on other sites More sharing options...
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