Large Glass Tank Builders, Please Help

[madrefkepr]

Hi All!

Have built 3 glass tanks now (5,10, and 29 gallons), and never had a leak, so I'm feeling pretty confident about building a 180. Yes, I do realize the pressures in the 180 are much greater, and thus the reason for this post.

The tank will be a standard 180 (72 x 24 x 24), using 15mm glass for the bottom (3/5), and 12mm (1/2) for the vertical panels. Tank will have euro-style bracing, 4" wide (GARF website says 2", but I'm paranoid ).

My question is about the molded frames usually found on the top and bottoms of commercially built tanks. I have not used any such frames on the tanks I have built so far, but am wondering if they assist in the structural integrity of a tank this large. I am thinking a frame would not be necessary for the top, due to the euro-bracing, but what about the bottom? What are your thoughts? Are these frames functional, or are they only decorative?

Another question about tank construction. All of my tanks so far have been built with all vertical panels on top of the bottom panel. According to some websites, this is correct. According to others, GARF included, the bottom panel should fit inside the vertical panels. In fact, according to the GARF website, the bottom panel should be raised 1/4" above the bottom of the vertical panels. This doesn't make sense to me. Your thoughts on this matter would also be greatly appreciated. Thanks in advance!

 

[Anonymous]

My 100 gallon, (72") has a bottom frame. It keeps the bottom pane of glass from being the lowest point, thus taking all the stress. Since the whole tank rests on the frame, the frame takes the weight, not the glass.

If you put the bottom inside the sides, it seems to me that the silicone would take all the weight, causing a greater chance for failure. I don't know, I'm not a glazier.

HTH

B

 

[madrefkepr]

Thanks, Bingo!

Haven't decided about the frame yet, but I think I will put the vertical panels of the tank on to of the bottom panel. I haven't had one leak doing it this way yet. And I agree, It just doesn't make sense to do it the other way.

 

[BRose]

In the distant past I used to build a lot of my own tanks. Mostly acrylic though. I found placing the verticals on top of the bottom pane works better and lasts longer. On most commercial tanks the frame both top and bottom does provide some structural integraty but the Top frame is as much for 'looks' and protection as anything. As indicated, the bottom frame on most carries the load of the tank and helps distribute and uneven and/or torsional distorsions. I've found that placing a tank on a 3/8" to 1/2" piece of dense bead foam does as much good or better. One distinct advantage to having frames top and bottom is handling and protecting the glass edges. Good Luck and Happy Building!

 

[madrefkepr]

One distinct advantage to having frames top and bottom is handling and protecting the glass edges. Good Luck and Happy Building!

Yes it does, and thank you!

 

[yimmit]

Here's a question for you... I have a 29 gal glass tank the I acquired from a friend and we have no idea how old it is. I filled it up a week ago right to the bottom of the top frame. One of the seams apparently isn't sealed with silicone at the very top because I can see water drip down in the seam between the two pieces of glass - capillary action. When the water level dropped enough, no more drips in the seam. My question is, is this a problem? I thought the panes should be sealed together, not just relying on the silicone bead to seal the seams. The tank has been holding the water for a week now, so I think it's okay, but I don't want to risk a flood if the seam should really be sealed.

Good luck with that 180 and let us know how it turns out!


Tim

 

[madrefkepr]

Yimmit,

I am far from an expert on tank building, but I have repaired leaking tanks before. Last one was a 65 gallon, that I cut all the silicone beads out and ran a new ones, in all joints. Worked just fine. FWIW.

 

[yimmit]

Thanks. I think I might just try it. My guess is it would start a slow leak that I could catch if the seam started to fall apart.

Tim