Glass L-shaped tank?

[coralnut99]

OK, so a while back I got my nephew's old 125 that was made with 1/2" glass all around. Without getting into the details, I ended up blowing out the back panel with a botched effort to put in external overflows (boy! did I learn a lot the hard way!). Rather than just throw or give away the damaged tank, I dismantled it. So I now have the bottom panel, one of the large viewing panels, and the two side panels standing up in the garage begging me to do something with them every time I walk past.

Has anyone out there ever built or seen an L-Shaped tank made of glass? My thought (my wife would call it a dillusion), is to use the two big panels for the bottom of a big old L-shaped tank. I know just how dead level the stand for this thing will need to be. My first reservation would be how to join these two panels. Would a simple silicone bead be enough? Should I add an overlapping panel where the seam is?

Any thoughts would be appreciated.

[Aqua Keepers]

I have seen one. So it can be done. Actually, it was a tank of the month from along time ago, but I'm not sure if it was in reefkeeping online or not.

[Aqua Keepers]

Found it, and it was'nt easy.

http://reefkeeping.com/issues/2003-12/totm/index.php

[drstupid]

i remember reading an on-line article about a large glass L shaped tank owned by a couple in australia. this was about three years ago. i don't have time right now to follow up on my initial googles, but maybe you can find something.

unless you're talking under 100 gallons, i think you definitely build this in place. it'd be really hard to move an L shaped glass tank w/o subjecting it to nasty torque it can't handle.

[coralnut99]

Hey Pito, Thanks! I appreciate it. But that's an acrylic tank. The bottom was most probably cut from one sheet of acrylic. I remember that tank from a long time ago too. I really like the orientation of the L facing out.

Drstupid, Oh I fully recognize it would have to be built in place and on a rock solid and level base. Torque on the base of a tank is something lots of people forget about in building/locating a stand, etc. About 10 years ago, I had the bottom of little 10G split wide open since i didn't support the bottom evenly on a rack. I just thought there wasn't enough weight for that to happen.

I have 2 six foot long panels so one side would be 8 feet and the other 6. I'm just at a loss as to how to best seam the two bottom panels. Maybe a third panel overlapping? Or maybe I'm just over thinking? If it's on a sturdy, level base, all I need is a silicone bead between the mating panels? I dunno.

[jpool3]

a friend built one along time ago. i dont remember the size. he gave it to another buddy and we cracked one of the panels in the moving process. damn thing was very heavey and extremely alkward to move. if my memory is correct the bottom was one solid piece. the only way i see using two seperate bottom pieces would be to build in place. then i would alway be worried about a leak or worse a blowout.

[Cuby2k]

Just cutting the bottom glass at a 90 degree angle is asking for trouble. I like your idea of butting the two bottom pieces together and then overlap with a third piece.

I think I'd set it on a rubber membrane like an exercise pad to help ensure it doesn't see an uneven surface. Honestly I think a well placed single joint on the bottom would do it.

Sounds like a cool project, keep us posted.

[jamal-188]

I think a third smaller peice overlapping the joint would be your safest bet. I don't know that I would trust just a bead of silicone.

Sounds like a project!

[coralnut99]

Thanks for the thoughts guys. The wheels are churnin' !

Cuby2K, I like the idea of a rubber membrane. With the odd and large surface area under it, any imperfection is cause for concern. Your thought also reminded me that this project would certainly require a solide bottom surface, and I probably wouldn't be abel to get away with a cheap grade of plywood either. Thanks.

I think I'm also sold on the idea of an overlapping panel over the butt joint where the two bottoms meet. Makes good sense, and can only help. I can size it to fit right inside the front and back viewing panels.

Over the holidays I should have some time to actually plan this out, and get the ideas out of my head and onto paper. Then comes the tough part: Selling this to my wife.

I think a design like the TOTM design Pito dug up, would actually be a major selling point with the wife. The fish room door opens out to the family room. So that there's plenty of air exchange, I've held back on installing a door. The light spill, and noise can get annoying at times. The outward-facing L would close it all in, and I can make the laundry room my sole access. OH MAN can this hobby make you sound like a lunatic, even to yourself!

Thanks for the thoughts! Anything else is more than welcome and certainly appreciated.

[jmkarcz]

I used to think it was a great idea... even saw one in a book once... could track down a pick easily, if you need me to break a copyright law drop a pm...

Are you going inside corner, or outside? I ask, because I remember reading that inside corners are diffidult because of the blind spot. A fish would be swimining along and suddenly jump position on a pannel.


J

[scottras]

This is something I am looking at for my next tank if I can afford it. If you are looking for pics of an L shape tank, here is an 18ft L shape tank from an Aussie reefer. Unfortunately not me.

http://reefcentral.com/gallery/showphoto.php?photo=167032&papass=&sort=1&thecat=500

There are more updates on the Aus forum that I am also on. If you want the site let me know.

[Cuby2k]

I gotta tell ya, when I read your first few lines I was thinking "oh man this is going to be a disaster". But then I read on and now after seeing a few more responses and thinking about this myself, I think it could be a very cool project and very worthwhile.

I am here for the long run should you decide to do it coralnut, I wished you lived closer cause I think I'd like to help put it together.

The more I think about the bottom seam the less I become concerned about it. If it is fully supported at the bottom with a cushy surface the chance of a blow-out would be minimum. Definitely less than an outside seam.

So you'd have to buy another piece for the bottom and two more sides right? And of course some top bracing. Could be very cool.

[Michael Mota]

The bottom would have to be one piece, if I was building it. I just would not trust it if it was siliconed together, just to much can go wrong. Especially if the stand is not perfect.
Good luck

[MimicTang]

Any idea of the kind of racking he was using for those tubs?

[syrinx]

I agree- the bottom has to be one piece. I recall glass tanks of this style in the seventies. Of course acrylic has been done also. I think the solid bottom aspect of this almost begs for a 100%DIY and go with a hybrid tank of plywood/resin and glass. That would allow not to buy any more glass perhaps and could be much more flexible in design. It also would allow for more common and forgiving tool use.

[bkwudzjeep]

I think DAS uses multiple panels for the bottoms of thier tanks. Maybe try to contact them. DAS = Dutch Aquatic Systems (out of Texas)

Good luck!!! Sounds like a fun project!!

[Cuby2k]

For those of you thinking a solid piece is best for the bottom consider the way glass is cut.

If a standard cutter is used the crack line would not permit the inside cut that is required. If a water jet is used the cut could be accomplished but due to the loading of the glass, handling would be extremely difficult and very susceptible to breaking. And the cost of a single piece of glass that size would be out of site. It would take a solid piece of 3/4" that starts with an 8' x 8' solid piece! Talking into the thousands of $$.

On the other hand, consider the seams on the outside corners of your tank, they take much more stress than a butt joint on the bottom. AND if two pieces were used in the butt over a cushy surface the ability to flex even if it's minimal could work to the advantage. A third lap piece would be added over the bottom butt joint after the sides have been placed and effectively increase the thickness of the glass at that point to double.

As fas as the silicon holding, have you ever tried to remove it from the glass after a full cure?

I hate to admit this but just about a year ago I filled my 180. I have two 2" holes drilled in the bottom for my closed loop and one of the bulkheads was undersized (different manufacturers). After planning for over a year, taking my time, reading and studying, etc., I was finally ready and one little old mis-sized bulkhead was not about to stop me. Sooooo, I filled the gap with type I silicon and it is holding!

Now I hate to admit that and certainly I would not advise it but a well placed silicone seal over a clean glass surface is extremely durable.

Coralnut, I am starting to think that my dream tank will now be a built in place "L" shaped. I hope you are able to continue this regardless of the time it takes and share the results with us.

Anyway, just some more food for thought.

[69vette]

<a href=showthread.php?s=&postid=8750086#post8750086 target=_blank>Originally posted</a> by Cuby2k
On the other hand, consider the seams on the outside corners of your tank, they take much more stress than a butt joint on the bottom. AND if two pieces were used in the butt over a cushy surface the ability to flex even if it's minimal could work to the advantage. A third lap piece would be added over the bottom butt joint after the sides have been placed and effectively increase the thickness of the glass at that point to double.


I would think twice about putting the bottom on a "cushy surface". You dont want the bottom to be able to move.

I've drawn up plans to build an "L" tank just like this in my basement. The stand will be built in permanently. I'm planning on using 2 peices of glass for the bottom and siliconing them to the plywood top of the stand. This would ensure no movement and guarantee that the seam would never leak. A lap peice would be a good idea if for nothing else but piece of mind.

[Cuby2k]

<a href=showthread.php?s=&postid=8750179#post8750179 target=_blank>Originally posted</a> by 69vette
I would think twice about putting the bottom on a "cushy surface". You dont want the bottom to be able to move.

I've drawn up plans to build an "L" tank just like this in my basement. The stand will be built in permanently. I'm planning on using 2 peices of glass for the bottom and siliconing them to the plywood top of the stand. This would ensure no movement and guarantee that the seam would never leak. A lap peice would be a good idea if for nothing else but piece of mind.

I think siliconing the bottom pieces to the plywood might be a scary idea Bob. I agree that it would ensure the bottom wouldn't leak but there are other things to consider. The idea of having some flex is for the advantage it gives during assembly. In a regular rectangular tank all of the glass pieces have to be perfectly square so the corners are flush. That requirement is compounded with the more sides that are required on an "L" tank. So my thought was allowing SOME minimal movement in the bottom DURING the assembly would better accommodate the assembly of the sides. And like I said the third lap piece joint would be added after the sides have cured.

And this is probably the most important part, consider the expansion rate differences between plywood and glass. Some expansion and contraction is going to happen and if the glass is secured too tightly to the plywood, stress fractures may happen. This could easily transfer to the side panels as well. A cushy surface under the tank allows for movement resulting from house settling, seismic events, and temperature changes.

Again just some more thoughts for discussion. I'd like to hear from someone that has built one of these. I know Acrylic would be more forgiving but baby I want GLASS!

[69vette]

<a href=showthread.php?s=&postid=8750341#post8750341 target=_blank>Originally posted</a> by Cuby2k
I think siliconing the bottom pieces to the plywood might be a scary idea Bob. I agree that it would ensure the bottom wouldn't leak but there are other things to consider. The idea of having some flex is for the advantage it gives during assembly. In a regular rectangular tank all of the glass pieces have to be perfectly square so the corners are flush. That requirement is compounded with the more sides that are required on an "L" tank. So my thought was allowing SOME minimal movement in the bottom DURING the assembly would better accommodate the assembly of the sides. And like I said the third lap piece joint would be added after the sides have cured.

I've built glass tanks before, and I don't understand why you would need, or for that matter want any flex from the bottom panel. I will be constructing the tank in a way that the sides are resting on the bottom panel. If your panels are cut square there won't be any issues. If they're not square, you shouldn't be using them.

And this is probably the most important part, consider the expansion rate differences between plywood and glass. Some expansion and contraction is going to happen and if the glass is secured too tightly to the plywood, stress fractures may happen. This could easily transfer to the side panels as well. A cushy surface under the tank allows for movement resulting from house settling, seismic events, and temperature changes.

The temperatures of the wood and glass will remain relatively constant, so the expansion rate differences will be minimal. The silicon between the bottom panel and the plywood more than allow for this. Also, mine will be on a concrete floor in a 30 year old house. It's already settled all it's going to. Seismic events are also not an issue where I live.