Replacing Bottom Glass & Cutting holes

I think the bottom of these big tanks are tempered glass. I know you cant drill them but most of the time they com drilled. Am I correct in thinking that temperd glass is regular glass heated up or something like that? If so they are probally drilled then tempered.
But this could be a load of crap, I really don't know.

Tampered glass has a film in between that prevents it from shattering out i think. If you are going to drill the bottom glass for overflow, build an overflow box into the side of the tank then drill the hole there. In this case the pressure from the water is not exerting on the hole itself but the partitions of the overflow box.

You might be able to get a piece of glass from perfecto ( they are build aquariums ) in Noblesville Indiana.

Here is their number 317-770-7900

THis is not as easy or safe a job as removing the old and replacing with a new sheet. The problem is that silicone does not stick to it self. When you cut out the old, there will be residual silicone on all the surfaces you need to mate up the nes sheet to. It will be a weak bond and a disaster is most likley what will happen.

If the bottom piece is in tact but cracked and all the seams are still glued to the sides and in good condition, how I would fix it is to silicone a sheet of glass either over the damaged area or more diffacult but better, silicone a sheet over the entire inside of the bottom of the aquarium. THis way the first bond (which is the best bond) is still in tact to hold everything together. It sounds as if all you need to do is seal up the area that would otherwise leak and have protection from additional runs in the glass if the water pressure caused any. Use the same thickness glass as is currently installed.

Drilling holes in glass is pretty straight forward, the diamond bit or the carbide type are the most common method, both are safe for aquarium use. THis size tank should have no less than two 1" drains in it.

Any good glass shop can cut and drill this but many freek out when you mention the word aquarium. If you take them a very accurate drawing of what you need with the hole location, it should be easy for them. THey don't need to know what it's for. I use GE's type I silicone for building aquariums.

Keep in mind, I've never seen this aquarium. Without seeing it I can't say for sure this is the way but I am positive that you cant just remove and replace with out having a major problem To do that, you will need to completly dissasemble the entire aquarium, have all the edges re surfaces either mechanically or chemically, then silicone it all back together. I have built and repaired many glass aquariums, some very large in the 500 to 1000 gallon range and even one larger. I've done it the wrong way before in my early attempt at building & repairing, it's a mess!!!

THe price is great, I'd buy it and re build it. YOu cant buy just one of the sheets of glass for that price. If you don't buy it, forward me the info, I have a project I'm doing this spring that the glass would be perfect for.

Joel

According to the chart it should be 16mm for the bottom.

Hey, sorry for the slow responce. was real busy today.

Experiance has taught me that you can scrape all day long and there will still be residual silicone left over. I have had 3 glass tanks that we built on sight that we have had to move afterwards that were to big to remove from the bulding in one piece. After razor blading all the edges for what seemed like forever, when I misted water on it, you could still see lots of silicone still present. What I do is mask off the area that need cleaned and either use a belt sander with a carbide sleeve to "polish" the edges and mating surfaces or I use an acid on these areas. When I'm done I have a dull, whitish surface that is clean, silicone free glass. At that point, it is safe to silicone back together.

I don't know of you will be able to get the existing pieces as clean as would be desired. If you overly chemically clean (acetone) you may damage the existing silicone in the corners that hold the sides & face together. What would you do in the bottom corners where you need to leave the existing silicone in tact? I'm just saying it's very risky removing and replacing. I am very experianced in building glass aquariums and I would not feel confident repairing it that way.

What I ment was that $75.00 is a steal. I was pointing out how great a price that is and that you would pay much more money than 75.00 for just one of those pieces of glass if you went to a glass shop and ordered one, you getting them all for super cheap!!!!

If I can offer any additional advise let me know...Joel

White vinegar and very fine sand paper works to remove the silicone residue.