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Stand bow, urgent ish help please.

mort

Member
Joined
15 Nov 2015
Messages
2,384
Hi guys. Can I have your opinions on this please as I'm just unsure of what to do. I've got so much going on at the moment that my judgement and nerves are shot tbh. I'm not sure if this is something that's been going on for a long time or if it's suddenly new but i noticed it today. The issue is on my tmc signature 60x45x45 cm tank I have notice the centre of the stand slightly bowing. The corners are all connected to the stand across both ends but on the length, front and back, I have about 10 cm connection one side and 9cm the other before the stand begins to fall away and in the middle there's a mm gap between stand and glass. Now if I had a foam base it would be fine but you are advised not to use them with these tanks.
I have had movement in the house and there is a fall of 5mm across the waters depth in the tank now (the side where i have 9cm connection is the higher water side, with 10cm connection on the other). Is it possible that this is causing the problem and if so can I just level the tank and it's likely to sort itself out?

So my dilemma and what I'd kinda like your help with please. Do I leave it as it's within tolerance? Do I need to somehow brace the stand and take out the bow? Or do I need a new stand?
I guess I could level it and then try to strengthen it but with only a 1mm disparity I'm not sure it would be that easy to strengthen because my diy skills might not be within that tiny tolerance.

Many thanks in advance
 
Hi Geoffrey, it's the standard tmc signature cabinet. There has been no water ingress into the stand and apart from the slight deviation across the length you'd never know it's not new. It hard to get a picture because the tank edges are bevelled and you cant make out the gap unless you are sat straight in front of it, eye level to it.
The best description I can give is that the corners of the tank are supported as is the case all along both outside edges but in the centre the bottom glass floats 1mm above the top of the stand, as you move out from this centre point the gap slowly reduces until the glass meet the stand again roughly 10cm from either corner. This is the same across the back so it's the centre that has dropped. Whether this is due to the shift in the floor I don't know.
For all I know it's always been like this and I've only just noticed it but with other things going on at the moment my clench factor has massively increased. I am comforted by it being supported in the corners and in theory it's within tolerance for the glass but I'm not liking it tbh and want to try and solve it before any problems. I know there was an issue with earlier 900 signature stands but can't find anything about 600 ones to find there tolerances. If it had foam underneath I wouldn't even notice and would be asleep by now.

I've got to be up early tomorrow so need to turn in but would appreciate any late night advice.
 
Hi

Hard to picture what the actual cause might be, any chance of a photo of tank and stand as that might help. i had a similar problem on mine and tapped a piece of wood in that at wedged vertically to support the middle and had to also tap a piece of wood in under the cabinet as it then also started to bow the bottom piece. However my stand was not purpose built for the tank and the tank didn’t quite go to the edges on the cabinet so all of the weight was on the middle.
 
For a quick fix buy some L brackets snd screw them to the inside areas you are worried about coming apart

Maybe do it the same time as a large water change to see if you can pull the cabinet together with less weight on it


Sent from my iPhone using Tapatalk
 
L brackets only stop it falling apart. You need to stop diaphragm action because the joints already exist.
What I do is to put a vertical wooden prop (2x4" or thicker) up the middle of the cabinet. I usually have to add a second prop under the bottom shelf where it transfers the load to the floor. I have used milliput to hold the brace in place if I don't want to screw it in place. You could probably do this with a steel tube, but it is more work. The cabinet needs to have no weight to wedge this prop effectively. I can get my dad to send us some pictures of a very expensive solid hardwood unit that I modified to take a Rio 125 by doing just this. It took about 10 minutes.
I know a lot of people tolerate a bowing tank. I don't. What in my mind, could if happen if it gets worse, is that the seal connecting the bottom pane of glass will slowly fail. It is unlikely to shatter, but if you have electrics anywhere near it, or in the floor, you might need to isolate those circuits. You need to look at whether the silicone is distorting. But it sounds like some scrap wood and a bit of milliput would put this matter to bed. Saying that, there are a lot of very bent stands that people have used for decades (masonry blocks and board), and exploding tanks are very rare. It's just the electricity and water thing that I worry about.
 
Hi

Hard to picture what the actual cause might be, any chance of a photo of tank and stand as that might help. i had a similar problem on mine and tapped a piece of wood in that at wedged vertically to support the middle and had to also tap a piece of wood in under the cabinet as it then also started to bow the bottom piece. However my stand was not purpose built for the tank and the tank didn’t quite go to the edges on the cabinet so all of the weight was on the middle.

You can't really see anything in a picture as it isn't that bad. All that has happened is under the middle of the tank the top of the stand has bowed downwards to leave a 1mm gap under the centre of the tank. So this part of the tank is floating and it continues, although lessens until you get about 10cm from the edges.

The tank itself hasn't bowed, it is supported on all the corners but I'm in agreemental Simon that you don't want any areas of the tank that aren't supported.
 
For a quick fix buy some L brackets snd screw them to the inside areas you are worried about coming apart

Maybe do it the same time as a large water change to see if you can pull the cabinet together with less weight on it


Sent from my iPhone using Tapatalk

The stand itself is still solid apart from the slight 1mm bow in the top it is as it has always been. I strengthened it before I originally used it but not under the top because it's only a 60cm span which should be no problem at all for a normal stand.
 
L brackets only stop it falling apart. You need to stop diaphragm action because the joints already exist.
What I do is to put a vertical wooden prop (2x4" or thicker) up the middle of the cabinet. I usually have to add a second prop under the bottom shelf where it transfers the load to the floor. I have used milliput to hold the brace in place if I don't want to screw it in place. You could probably do this with a steel tube, but it is more work. The cabinet needs to have no weight to wedge this prop effectively. I can get my dad to send us some pictures of a very expensive solid hardwood unit that I modified to take a Rio 125 by doing just this. It took about 10 minutes.
I know a lot of people tolerate a bowing tank. I don't. What in my mind, could if happen if it gets worse, is that the seal connecting the bottom pane of glass will slowly fail. It is unlikely to shatter, but if you have electrics anywhere near it, or in the floor, you might need to isolate those circuits. You need to look at whether the silicone is distorting. But it sounds like some scrap wood and a bit of milliput would put this matter to bed. Saying that, there are a lot of very bent stands that people have used for decades (masonry blocks and board), and exploding tanks are very rare. It's just the electricity and water thing that I worry about.

Thanks Simon. I'm still not sure if this is a longterm issue that I've only just noticed or if it is the start of something new. I'm tackling it like it's new and that it's something I want to solve before it gets the chance to weaken the seams. I think this might be the result of the recent movement in the floor, twisting the stand slightly.
 
I don't know how long you've had the tank and cabinet but it might be worth contacting TMC, even if it's to get their opinion on it.
I'm not familiar with the cabinet but most have a brace at the front in the middle where the doors meet. I'm paranoid about tanks breaking (after a our tank broke when I was a child) so when I've made cabinets I always add a central brace as described and if there's the chance that a sump might be added, I make it removable. One thing about adding any brace retrospectively with the tank in place is that you won't know if you are causing a bow in the opposite direction, making a pressure point on the tank, which I imagine would be worse. If you get some paper and cut it into narrow strips you can use it to gauge how far back the bow goes and also measure the gap by layering the paper strips (same principle as feeler gauges, if you have some even better to use those). Measuring the gap might allow you to cut the brace accurately enough to avoid bowing in the opposite direction. Adding a lateral piece of wood beneath tank (inside the stand) and then add the vertical brace pressing up on to the lateral piece would help dissipate the force more evenly.
All that said tanks with floating bases are normally just supported on the corners and I've seen people doing the same with rack systems. As I say I'm just paranoid.
 
You can't really see anything in a picture as it isn't that bad. All that has happened is under the middle of the tank the top of the stand has bowed downwards to leave a 1mm gap under the centre of the tank. So this part of the tank is floating and it continues, although lessens until you get about 10cm from the edges.

The tank itself hasn't bowed, it is supported on all the corners but I'm in agreemental Simon that you don't want any areas of the tank that aren't supported.

There are many many people who have tanks that are only supported at the ends In their fish houses, I’ve seen 6x2x2 sat only on 2inch wide wood at each end i personally have done it with 36x15x15” tanks that were like that for 20 years

So I would not worry about a slight bow in the top panel

Initially I thought your problem was much worse that’s why I suggested the L brackets to keep things together

Putting a support mid tank as suggested will just distribute the load to the base panel, which I believe has a void under it ? Actually using a beam will transfer the weight but onto a small area of the base which isn’t ideal plus it will reduce the cabinets usefulness for storage

The solution that will strengthen the top panel and save space is to get up to 3 panels glued in place across the width of the cabinet, use some 18mm board thats 100mm wide and exactly the same length as the gap between the two side panels, I don’t know if your cabinet came with a full width shelf but if it did you could cut this up to make the panels

Fit the new panels to the underside of the top panel and to the side panels with either L brackets, wood glue plus areas of super glue to hold it in place while the wood glue dries or a combination of all 3
Place one in the middle, and the others on the front and back edges ( or inset slightly depending on location of door hinges and your fixing method

Ideally the bow of the top panel should be straightened at the same time

But this method will stop it bowing ever again plus keep the usefulness of the cabinet for storage


Sent from my iPhone using Tapatalk
 
Thanks scarecrow.

Working in the trade I know that tanks are often just supported on the edges but I also know a hell of a lot of failures from other people's tanks and at the moment I didn't want to risk any possible damage to the seams. I spoke to an old rep who worked where they were made and he was surprised on had lasted this long, which filled me with confidence. Since I've had some movement in the floor I'm even more paranoid about further twisting of the stand and the lack of any leeway without a foam underlay. The stand has no central support as it's only 60cm wide, it also has no shelf which is why I braced it.

Hi Dean,

Looking at the stand today and knowing these I was just not cofident I could brace it safely without difficulty. I completely understand what you are suggesting but it would have been a lot of hassle to get it to a point where I would have been happy, so I took the easier option and swapped the stand. Luckily I had a pine stand I'd made or 4x2" and its strong enough to hold up a car. It's meant I can use an underlay and level the tank on a piece of ply.
When I moved the old stand and inspected it, it appeared to have the structural integrity of a mature cheddar, without the weight of the tank the seams opened which I didn't notice yesterday when I had done a large waterchange. If I'd have put screws into it any water ingress seemingly makes them fail quite quickly, judging from my friend who worked at tmc. I've never really liked the design or build quality of the stand but it had done a decent job till now, I just didn't have any faith in it. If it was in my garage I'd have braced further and left it but not in the house. It's now only going to have to support a couple of plants in the conservatory.
 
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