Need experienced/fast advice on bowing

[Jon M]

glass will bend just slightly, I noticed it first on my 30 inch long tank, the long side was bowing just a bit to the naked eye, I was a bit worried but then took a long ruler to a 55 gallon tank and even though they didnt look like they were bowing to the naked eye, there were in fact bowing a bit in the spans between the braces. bowing for thinner glass such as mine and your tanks isn't too bad, its the thicker glass that can fail catastrophically due to the compression of the inside and the expansion of the outside face.

Good to know. Bowing by how much? I'd like to hear other peoples tanks bow 2-3 16th of an inch and it's normal.

if these are braceless 40g breeder tanks from Aqueon (Allglass), slight bowing is normal because there is no brace.

this question has been asked before and a response was posted from Cental Pets (the company who owns Aqueon)

I would not be worried if they are.

That's exactly what I wanted to know. These are both standard newer aqueon 40g breeders. At first when we built the stand I believe the surface wasn't level and a tad of the corners were elevated. When I filled half way I realized the tank lid didn't fit in the lip and then realized it was twisting the tank a bit so drained it and added plywood on the stand. Still not perfectly straight but better... 3 corners are down and I put a wood insert on the 4th corner and it all seems fine.

 

[Pharaoh]

I have three 40Br that all bow when filled. You should be good as long as the tanks are level.

 

[Jon M]

Well we sanded the hell out of the plywood but for some reason the tank still didn't sit straight when on so the tanks are touching in 3 corners and have a wedge holding them up in the fourth. I was recommended to use insulation board from HD to correct this issue on another thread I just want to make sure that'll fix my problem before I break down the whole tanks move them and put insulation board under. The corners that have a gap are a good 1/16". Will setting some 1/2" insulation board down, not screwing it down, and putting the tank on that fix the issue and allow me to remove the wedge from the corner and let the tank sit straight? Is the stuff soft enough to let the tank sink 1/2 way into it?

 

[Bderick67]

Foam does very little on plastic framed tanks. Sure it wlll give the illusion of filling the gaps but it does not support the tank where those gaps are present. You need to rework your stand to where all four corners are supported, if you have small gaps along the length that is OK as long as all 4 corners are solid.

 

[deeda]

Brian gives you excellent advice in the above post. You should NEVER shim the tank, only the stand.

 

[12 Volt Man]

Good to know. Bowing by how much? I'd like to hear other peoples tanks bow 2-3 16th of an inch and it's normal.

its always normal on braceless tanks.

back in the early 90s when I got started, no tanks had braces. all had a slight bow.

granted, they used thicker glass back then (eg. 90s made with 1/2", 65s made with 3/8ths where today a 150g uses 1/2" but its braced etc..)

still, I prefer the no brace thicker glass tanks.

the companies all began using the plastic trim with braces in the late 90s.

the spin they put on it was 'its to prevent bowing' which was bull.

it was actually because it was cheaper to make the whole tank out of thinner glass and use plastic one peice trim with braces than to make the tank properly with the correct glass thickness..and they still charged the same LOL

thats all it was.

 

[Jon M]

Foam does very little on plastic framed tanks. Sure it wlll give the illusion of filling the gaps but it does not support the tank where those gaps are present. You need to rework your stand to where all four corners are supported, if you have small gaps along the length that is OK as long as all 4 corners are solid.

I can see how foam wouldn't provide much support in these sections or in this case the single corner but what about the insulation board? That so far as been my plan today to fix the issue. I'm about done with draining 2x tanks, removing all stocks, and redoing the whole tanks so this has got to be the last fix. I sanded it for hours and the corners for some reason still don't line up with the one in the back right. I think it's an error while constructing the stand but I need to make sure the tanks are safe.