View Full Version : just asking ?

02-22-2003, 04:25 PM
hello all I was just wondering about a tank bottom out of wood has anyone ever tried it only because I have a 150 gal tank that the bottom glass crack on while I was moving to Tx. from Ct. any help would be greatly appreciated.

02-22-2003, 11:36 PM
I have never tried wood for a tank bottom. It may be possible. However, I have used glass to make a patch. It all depends on the nature of the crack. One advantage of patching the bottom is that it does not flex like the sides when filled with water IF you provide total support beneath it. If the crack is straight across from side to side, just cut a piece of glass that is wide enough to cover the crack with plenty of extra on both sides -- run some silicone down the crack and spread a smooth coat over the entire area where you lay the patch. Apply the glass patch--press it down tightly - lay something heavy on it to keep it down while it dries-- then run a bead of silicone completely around it , sealing off the entire bottom. This is not attractive, but it will hold if the bottom is evenly supported.
I have also patched a thick glass tank like a 150 by just placing a piece of quarter inch glass over the entire bottom on the inside. Cut the silicone bead away - run silicone down the crack and spread enough on the bottom to seal the new glass securely. Place it on the cracked bottom -- weigh it down securely-- and then run your new bead of silicone around the perimeter to seal it off. If you use the tank barebottom, neither is attractive, but if you use gravel, you will never know the difference. Just support the bottom securely. Both ways are cheaper and easier than replacing the entire bottom with 1/2 or 3/8 glass.
However, replacing the bottom is still the best solution. Especially if you may want to sell the tank someday. HTH

02-23-2003, 01:55 AM
I've been trying to think of where I saw a post on an all wood tank (with a glass front of course). It was the complete instructions for building a wooden tank, the tank was huge too. It talked about the joints and treating the wood. It may still come to me.

Richman, I never would have thought of a glass patch. On the first option, was the patch on the inside or outside of the tank? Does it matter?


02-23-2003, 06:27 AM
The patch needs to be on the inside. When the tank is full the water pressure would then be dispersed over the entire patch.
Donna :)

02-23-2003, 09:26 AM

You might have seen the wooden tank on the "old DAAH"...Jim Quarles used to make them. He had a MASSIVE one in his basement, but made smaller ones also.
A plywood box was made with a cut out in the front(for the glass) The inside of the box was then sealed(and strengthened) with several layers of fiberglass resin. Im sure it worked well, although....even though it would be cheaper than a glass tank....it seemed to be a huge amount of work comparatively.

Ive also seen/heard of someone using epoxy paint rather than the fiberglass resin...I dont think I would trust the epoxy myself though.


02-23-2003, 10:46 AM

Donna is right. The patch must go on the inside. You can use a piece of glass much thinner than the original glass. Just make sure that the bottom is supported very firmly before filling the tank. Remember that a tank is normally resting on the frame, not the glass. I made sure that the support is under the glass itself.

02-23-2003, 09:45 PM
Ya know Tony I remember seeing a thread regarding wood tanks as well. But..... I do believe it is here somewhere..... lemme see what I can come up with....

Here is one of them.
http://forum.simplydiscus.com//index.php?board=1;action=display;threadid=471;star t=0

02-24-2003, 12:44 AM
here is the monster wood tank link;action=display;threadid=648

as for the patch, would it not be the best in the long run to just remove the bottom trim ring, break out the bottom, clean up the surfaces and put a new bottom in, silicone the trim ring back on and rest easier knowing it was done right?


02-24-2003, 01:40 AM
Of course. As I said, that is the best in the long run, especially if you have any intent to maybe sell the tank someday. I was just offering an easy, quick, and cheaper solution. Thought maybe that was the purpose of the wood idea. ;)

03-06-2003, 07:25 AM
I have had to repair cracked tanks, lots of them over the years. Yes, get a piece of glass, 1/4"", and follow richmans instructions. This method works extremely well.
For added strength and support, yuou could place some rigid styro foam under.. just enough to support the glass. Be carful here, remember just enough thickness to support the tank bottom ,,, not the entire tank .


03-06-2003, 09:18 PM
I couldn't believe how expensive glass is, especially the thicknesses seen in aquariums. Any alternative to spending that kind of money is a good one.

03-09-2003, 03:30 PM
wood tanks are great - i've made many of them all the way up to 220 gallons - never had one leak. solid as a rock.

i wouldn't trust wood siliconed to glass unless it was the front pane of glass in an all wood tank.

if you must try it - make sure that you use a fiberglass resin or epoxy paint painted over the wood before siliconing the wood to the glass.

also sand the resin coating on the wood before siliconing so that the silicone has something to bite into.

Mr. Limpet
03-09-2003, 11:23 PM
I had a 55 that i woke to one morning and couldn't quite figure out what I was seeing. It was a BB, so I could see that something was wrong, but the water level was fine. It had cracked on the bottom, from front to back, at a slight angle near one of the sides. As I realized what had happened, I couldn't understand how the water was still in the tank. It was just weeping through that crack at about a drop a second. My lucky day I guess. I emptied it and just ran a thick bead of silicone over the crack. It held for years until I got rid of it. Depends on how bad the crack is, as to what you need to do about it. Paul.

03-13-2003, 07:09 PM
About a year ago, I bought a 200 gallon Oceanic with cabinet stand for $35 because it had a broken end piece of glass, and the bottom was cracked. I talked to some people that have repaired big tanks, and even talked to the aquatic technician/CEO of Oceanic, and he recommended the following. Since the structural integrity of the bottom of the tank was still in place, for the most part (the crack was in the shape of a big X in the middle of the tank, from front to back). He recommended against using plexiglass (as the local glass guy recommended), since it is hydrophilic (which means it will expand when filled with water, I think), and that glass was hydrophobic, thus wouldn't change when water was added. He recommended I cover the entire bottom of the tank with a piece of 3/8" plate glass, and to clean away the silicone from the bottom, and make sure the bottom glass is completely clean. I used new razor blades, Scotch brite, and Acetone to clean everything. He didn't recommend laying down a layer of silicone as a sandwich between the two pieces of glass, but said to make sure everything was just spotlessly clean. I laid the glass in there (with the help of the glass guys suction cup handles, when they delivered the 7'x2' long piece of glass), then siliconed all around the edge of the new bottom glass. Then I siliconed in my end piece of 1/2" plate glass in the end.
The guy at Oceanic also recommended I cut a piece of 1/4" plywood (I think it was actually like 3/16" or some oddball size these days) to fit under the tank, between the bottom moulding. I did, and it was the exact right thickness. Then I got a piece of 1/2" styrofoam that they use to insulate the side of houses, that has a plastic/foil covering on each side. This, I placed under the tank/plywood wafer, and all this sat on top of the cabinet stand. This gave me a beautiful tank that has been in service without a leak of any sort for about a year now. For under $200, and some of my time, I got a couple thousand dollar setup that houses about two dozen of my adult discus right now. ;D
I just bought a 150 gallon (72"x18"x28") Oceanic for $50 with a cracked bottom, and plan to do the same with this one. If you have any more questions, then let me know. I'll be happy to expand on what I've said above.
Lance Krueger

03-13-2003, 10:04 PM
Lance, I appreciate the post, very informative.

I've fixed a couple tanks, nothing that size though. It is definately a money saver and the work is not that complicated. There is a risk involved but I have also heard stories of new tanks leaking.

Where did you buy the replacement glass and how much was it, if you don't mind my asking?