David R Posted March 30, 2008 Report Share Posted March 30, 2008 I'm setting up my 160g (150lx70wx60h) in the garage on the bare concrete floor. I had a stand made from 30mm square steel, with eight legs (see pic). I'm in a bit of a predicament; the stand has a slight twist, so when the front left leg is on the ground the back right is about 4-5mm off the ground. Two people (around 60kg each) standing on opposite corners is enough to flex the stand so it is level. Obviously the weight of the full tank will be far greater than this, so it will level itself out, but I'm worried about the force stressing the tank, and possibly cracking it. The tank is made from 12mm glass and and has bracing along the front and back, top and bottom. The other thing is that the ends of the legs and the concrete is not perfectly parallel, so I was thinking of putting a piece of 3x3x1" timber under each leg to act like polystyrene under a tank and even up the weight. Is this a good idea, or is the wood likely to crush and split with the weight of the tank on it? I think I may just be being paranoid, if it was going on a floor with carpet you probably wouldn't even notice little things like this! :screwy: Here's the stand and tank: Quote Link to comment Share on other sites More sharing options...
smcoleman Posted March 30, 2008 Report Share Posted March 30, 2008 hi mate when i had my 5 foot tank i put a peace of ply wood on the stand before the poly an tank an i didnt have a proplem mine had a twist in the stand as well Quote Link to comment Share on other sites More sharing options...
Ira Posted March 30, 2008 Report Share Posted March 30, 2008 You sure it's the stand and not the floor that's warped? Quote Link to comment Share on other sites More sharing options...
Stella Posted March 30, 2008 Report Share Posted March 30, 2008 What is going to go inside the stand? Would you be able to put a board across as a shelf and some weight down there to straighten the stand? Though with no central strut it may just bow the board. Hopefully the poly under the tank would take a lot of the stress out of the situation. Yes you are probably being paranoid, but I can totally understand! A cracked tank is a pretty serious issue. Quote Link to comment Share on other sites More sharing options...
Warren Posted March 30, 2008 Report Share Posted March 30, 2008 The joys of welding steel. You should be able to straighten the stand by putting packers under the two legs that always touch the ground and bouncing on the opposite diagonal with two people. Once it's flat you can fit some boards or diagonal bracing to it as well. This stand will need it in an earthquake or it's likely to pancake itself with a tank that big on it. To fix the concrete issue do this: 1. Put 2 x levels on the stand - one front to back and one left to right. 2. Find the highest point - the leg that both bubbles point to. 3. You need to pack all other legs. 4. Pack the leg diagonally opposite the leg in 2 until both bubble are in the center of the levels. 5. Pack the other outside legs re-checking the levels. 6 Pack all other legs. Use steel packers straight onto the concrete. Get some 50x50mm squares cut out of varying thickness and stack multiples together to get the thickness required for each leg. A bit of ply on the top of the stand is always good but it will need to be very thick to have any real support for the unsupported areas of the glass. I'd expect at least 30mm for a tank this tall. You can glue the ply onto the stand as well. If you use no-more nails between the ply and tank and sit the empty tank on the ply while the glue sets (3-4 days) you will end up with a much more level interface between the stand and tank. Fit 10-15mm poly between the wood and tank before filling of course. Quote Link to comment Share on other sites More sharing options...
David R Posted March 30, 2008 Author Report Share Posted March 30, 2008 smcoleman- I've got a piece of 15mm ply to go on top of the stand, just finished painting it somewhere else. Ira- the floor isn't 100% perfect, I've tried the stand in various locations in the garage and it varies from being nearly 10mm out to sitting nearly perfect. However, in its final location with people standing on the stand to take the bend out of it, I've checked it with a spirit level and it looks pretty good. I have some pieces of 1mm and 2mm thick steel to shim it if needed. Stella- yeah I think I may be being paranoid, as you probably wouldn't even notice such small gaps on a floor with carpet. The poly will help a little (I think) but its more for absorbing small bumps [like a proud screw head] than twists. I've got a sheet of 10mm polystyrene, will that be thick enough? As I understand, anything thicker isn't necessary because they poly is only good for absorbing small defects, certainly nothing anywhere near as big as 10mm. Cheers Quote Link to comment Share on other sites More sharing options...
David R Posted March 30, 2008 Author Report Share Posted March 30, 2008 Thanks Warren. I'll try straighten it out tonight. What would you use for diagonal bracing? Thick ply/mdf screwed to the ends and back of the stand? I've never actually seen a steel stand with diagonal bracing, even on the massive display tank at HFF Albany. Lucky we don't get too many earthquakes up here! Quote Link to comment Share on other sites More sharing options...
Warren Posted March 30, 2008 Report Share Posted March 30, 2008 You won't need too much in the way of bracing. If MDF or Ply is used it will only need to be about 9mm thick and fitted to the sides and back. If steel is used, 2 braces across each diagonal of the back and both sides 2-3mm thick and 25mm wide would be more than enough. They will need to be well screwed on though with well aligned holes. Quote Link to comment Share on other sites More sharing options...
alanmin4304 Posted March 30, 2008 Report Share Posted March 30, 2008 The bottom of the tank should be straight so if you place it very carefully on the stand you should be able to tell if the stand is straight or not. It would be a pity to bend the stand if it is actually straight, as this will put stress on the tank when it is not supported properly and full of water. Quote Link to comment Share on other sites More sharing options...
Warren Posted March 30, 2008 Report Share Posted March 30, 2008 Good point! Quote Link to comment Share on other sites More sharing options...
David R Posted March 30, 2008 Author Report Share Posted March 30, 2008 Good idea Alan, I could put the tank on the stank with no ply or polystyrene, and see if/how much it straightens it out and which legs need to be shimmed. I've checked it with a spirit level and I'm certain the stand is twisted. Quote Link to comment Share on other sites More sharing options...
Robert Smith Posted March 31, 2008 Report Share Posted March 31, 2008 A level cannot tell you that the stand is twisted unless it is a very long and very straight one, in which case you're using it as a straight-edge, not a level. If you're using the 'level' part of it then you cannot be sure. If it's a good level then the straight-edge might be long enough to show any warping of the top pieces of metal, but even then I suspect not. I think the suggestion to carefully place the empty tank on top is the best. That will tell you if the frame is warped. If it's not then you just pack out the legs. Some people say measure three times and cut once, others say measure once carefully then cut once carefully. Me, I typically measure three times and usually end up cutting three times anyway. Knowing my limitations, I only ever make tripods. The benefit of this is that all our furniture fits nicely into the corners of the rooms. The downside is that this includes the dining room table and all our chairs (stools), but thank God for corner baths and flat screen TVs! Quote Link to comment Share on other sites More sharing options...
David R Posted March 31, 2008 Author Report Share Posted March 31, 2008 A level cannot tell you that the stand is twisted unless it is a very long and very straight one, in which case you're using it as a straight-edge, not a level. If you're using the 'level' part of it then you cannot be sure. There are four bars running front-to-back. The left hand one is level, the right hand one is on a lean (higher at the back than the front). Does that not confirm that the stand has a twist? Quote Link to comment Share on other sites More sharing options...
alanmin4304 Posted March 31, 2008 Report Share Posted March 31, 2008 No. Quote Link to comment Share on other sites More sharing options...
Robert Smith Posted March 31, 2008 Report Share Posted March 31, 2008 Ditto. And that only gets worse because you have eight legs. You can prove it to be warped/not warped using a level and a ruler and assuming your floor is a flat (but not necessairly level) plane, but it's unlikely to be reliable enough. Quote Link to comment Share on other sites More sharing options...
David R Posted March 31, 2008 Author Report Share Posted March 31, 2008 No. Care to elaborate? If the left hand end of the stand isn't parallel with the right hand end, then the top isn't level, right? I guess it could have been made crooked, and may not necessarily twisted. Stupid steel, should have just stuck with what I knew and made a wooden one. I'm so over this tank already! :evil: Quote Link to comment Share on other sites More sharing options...
Simian Posted March 31, 2008 Report Share Posted March 31, 2008 Take the thing back to the engineering w/shop you got it made at and get them to straighten it, if you paid for it it has to be right! If it was me I'd just put a bit of ply and poly on it and fill her up. Quote Link to comment Share on other sites More sharing options...
Robert Smith Posted April 3, 2008 Report Share Posted April 3, 2008 With a level you are measuring whether the metal is "level", and if the floor is not level, or the legs are not even then you can get the wrong result. With 8 legs you make the chance of one leg being the cause of being out of level much higher. what you need to measure is whether the tank support is planar. If you have a piece of plywood or other planar material (like the base of the glass tank) then drop that on top and see if it touches all the supports without bowing. If yes, call it planar and drop your tank on top and verify it sits evenly. Then you can block up any legs that you need to to ensure the tank is level (ie. not on an angle, as opposed to twisted/warped) so that the water doesn't all pool down one end (which, by the way may be easier and faster than using a level to align then tank, just drop a litre or two of water in the bottom and watch where it pools). Quote Link to comment Share on other sites More sharing options...
Warren Posted April 3, 2008 Report Share Posted April 3, 2008 Care to elaborate? If the left hand end of the stand isn't parallel with the right hand end, then the top isn't level, right? I guess it could have been made crooked, and may not necessarily twisted. Stupid steel, should have just stuck with what I knew and made a wooden one. I'm so over this tank already! :evil: You are correct, if one end is showing as level and the other isn't then there is a twist somewhere in the stand. It's unlikely to be coming from the floor as this stand looks easily to be stiff enough to support it's own weight without twisting due to the floor. Maybe the correct term to use is flat. Quote Link to comment Share on other sites More sharing options...
David R Posted April 3, 2008 Author Report Share Posted April 3, 2008 It's unlikely to be coming from the floor as this stand looks easily to be stiff enough to support it's own weight without twisting due to the floor. I'd hope so, it has to support 600kg+ of fish tank!! I still haven't been able to get enough friends over to comfortably lift the tank (two can do it, but I think it would be better to have four to place it gently on the bare steel) so I can't report any further progress. Hopefully this weekend! Quote Link to comment Share on other sites More sharing options...
Mooloo Posted April 3, 2008 Report Share Posted April 3, 2008 where in auckland mate? i may be able to help with a lift. or removal of said stand............ :lol: :lol: Quote Link to comment Share on other sites More sharing options...
David R Posted April 3, 2008 Author Report Share Posted April 3, 2008 In Mt Wellington. If we don't get it sorted this weekend I'll put out a call for help! Quote Link to comment Share on other sites More sharing options...
AMAZONIAN Posted April 3, 2008 Report Share Posted April 3, 2008 Hi All. Turn the stand upside down and sit it on the top of the tank. It should be a close fit all the way around. If the glazier is any good, he will have cut the glass perfectly which means the bottom and top will be parallel. When you put he stand up the right way in its position You can pack under the LOWEST legs to get it level, then put your board on top of the stand, then your poly sheet and then the tank. Check it for level before adding water. EWS steel which this is made of is very difficult to weld unless you have a TIG plant as it's so thin it warp very easily. When I make all steel stands, I weld adjustable feet into the bottom of the frame Tubing. Its a lot easier to adjust than by using packing. Good luck. Quote Link to comment Share on other sites More sharing options...
livingart Posted April 4, 2008 Report Share Posted April 4, 2008 EWS steel which this is made of is very difficult to weld unless you have a TIG plant as it's so thin it warp very easily. When I make all steel stands, I weld adjustable feet into the bottom of the frame Tubing. Its a lot easier to adjust than by using packing. good idea on the adjustable feet, they could still be fitted to this stand when i weld stands any thing over 1 metre long i use the 50mm x 20mm ews on its side for the long runners it helps prevent the twisting that can happen, weld middle supports in afterwards Quote Link to comment Share on other sites More sharing options...
David R Posted April 7, 2008 Author Report Share Posted April 7, 2008 I put the tank on the stand tonight, and the top is nowhere near level. Seems to be sitting on the points where the two centre legs are, and both ends are low, about 4mm out at the worst point, and about 1-2mm on average. I've shimmed it to where I think it should be level, and the four centre legs are off the ground. I've put some large plastic containers on top of it and filled them with water so there's about 150kg on there trying to sag it a bit so all the legs are on the ground. So, I'm going to do the liquid nails thing under the ply to take out any unevenness, how big a gap can I rely on it to fill in?? Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.