Glass tank building

[JayM]

Bump.....


Can anyone help with figuring out glass thickness?

I want to build a 36x24x20 rimless. I would like to build on top of the bottom (not around it).

My assumption is that 12mm would be good all around. BUT, one person said I would need 19mm for the bottom.

I haven't been able to find a calculator anywhere that considers braceless vs braced, or bottom under vs inside

Can't quite get glass qoutes til I know what to ask for....

tagging along....thinking about either a 30x30x24, or a 36x36x24

 

[Joel A]

I think 12mm all around would work fine, but 19mm on the bottom wouldn't hurt anything either if you don't mind a bit of extra money and weight.

 

[Dave McReeferson]

dave what was the total cost for the tank you built at cra? I've never purchased glass. It
think it would be a cool project for me in the near future.

I think they said it was about $200 worth of glass.

I have been pricing glass for the 36"x36"x24" tank I want to build and it would cost me $300 for 1/2" glass

It cost me around $280 (dug out the reciepts), but I think a little shopping could find you a price closer to 200-225.

Silicone does not bond with acrylic with anywhere near the strength that it will with glass. That said, it works fine for installing things like overflows and baffles in sumps. It sticks, just isn't as strong on acrylic.



My next question is about supporting the bottom?
With a tank build on top of the bottom pane of glass (just like the demo build), what support is needed on the bottom?
Does it need to be supported throughout, or just around the perimeter? Anything special to keep in mind?

I want to build the stand with a little shelf around the base of the tank. ie, I want the stand to have an extra 3" sticking out around the tank. I'm picturing a rectangle made of 4x4"s that would sit below the perimeter of the tank, with a sheet of 3/4" ply as a top surface. Then build a standard stand underneath to hold that table top assembly up. Sound OK?

That would probably be fine, but I'd personally double up that ply top or add a cross beam.

well, like you said earlier, you wanted a bullet proof tank.. so i'll throw out two nice bottom bracing options out there for you.

Higher end tank builders like AGE use two panes of bottom glass, one for the vertical glass panes to sit on top of, and one that the vertical glass panels sit flush with, so it sits on top of a glass panel, and then a glass panel sits inside all four vertical panes. This is more expensive, and a bit more complicated and time consuming to build, but does wonders for strength and bottom bracing.

Another nice otpion is a eurobrace around the bottom... maybe 4" or 6" of eurobracing along the bottom pane... great thing is that it adds extra support, but you never see it because the sand covers it... so even though it may be ugly, you never see it and it adds good support. Glasscages uses this technique on like all of it's tanks... if you eurobrace you want tempered glass IIRC.

I bottom euro-braced the big tank, but don't really think it was meccesary strengthwise. The main reason I used this technique was to ease the assembly procces by having pre-attached placement guides. Those panels were heavy, and hence tough to work with. Fwiw, I used no tempered glass in my build.

I like the idea of the two bottom panes, but are they bonded together?

Also Dave I like the idea of the black acrylic between two panes, are they bonded along each surface, or just along the edge?

Should the tank be drilled before it is assembled, or after?

TIA Derek

The "sandwich" pane I reffered to did not use acryllic, but rather PVA (IIRC), I believe this was accomplished by heating, but am not sure, so don't quote me there.

Bump.....


Can anyone help with figuring out glass thickness?

I want to build a 36x24x20 rimless. I would like to build on top of the bottom (not around it).

My assumption is that 12mm would be good all around. BUT, one person said I would need 19mm for the bottom.

I haven't been able to find a calculator anywhere that considers braceless vs braced, or bottom under vs inside

Can't quite get glass qoutes til I know what to ask for....

Before jumping in with the glass calculations, may I ask why you are thinking rimless? Are you planning to set up an open to tank where a rimless tank can be appreciated, or will you have a hood. If you are going open top, then that's great, but if you are planning on having a hood, I would try and steer you towards eurobracing. It really is not much more complicated than the build you saw me do, and has some definite upsides over a rimless tank when a hood is used IMO.

 

[JohnK]

"Before jumping in with the glass calculations, may I ask why you are thinking rimless? Are you planning to set up an open to tank where a rimless tank can be appreciated, or will you have a hood. If you are going open top, then that's great, but if you are planning on having a hood, I would try and steer you towards eurobracing. It really is not much more complicated than the build you saw me do, and has some definite upsides over a rimless tank when a hood is used IMO."

I would like to be able to display the tank without a canopy. I May build a canopy to put on temporarily when I don't want to light up the whole room, but I definately want rimless (at least until I price out the glass )

 

[FOXYB]

could we compose a list of glass shops?
i went out this weekend to get some prices on glass for a sump id like to make and i came back with some outrageous prices.....

 

[Dave McReeferson]

I made the assumption that the "20" was the intended height, and came up with 1/2" glass giving you a safety factor of somewhere around 7, and a bow of ~.005", and 3/8" glass giving you a 4-5 safety factor with a ~.011 bow.

I'd say either would probably work fine, but would personally opt for the 1/2".

 

[JohnK]

That works.

How about the bottom? Do you think that would need to be any thicker than 1/2"?

 

[Dave McReeferson]

In keeping with my standard mode of thinking, I would steer you in a different direction than some others might on the bottom pane. If you were looking to pinch your pennies and get the max for the min, I'd say to go 3/8" on the bottom, and 1/2" for the sides only. Repeating what I said at the meeting, why waste money on a pane of glass you'll never see? Make a sturdy stand, and go thin on the bottom. If it is well supported, the way I see it, it technically matters not whether your bottom pane is three eighths inch thick, or a mile, it's sole purpose is to provide a bonding surface for the sides. You may even be able to get away with 1/4" glass down there, but I would be shy of trying that myself.

 

[JohnK]

OK, right. I took the same approach building my acrylic sump, but somehow glass seemed different. (that and the guy telling me I needed to use 3/4")

 

[JohnK]

OK, here's a new one. I called several suppliers today to request quotes.

One sales rep I spoke with stated that the polished edges would be terrible for adhesion and not to try it at all. We talked for several minutes and he was quite nice about it, and said he would happily order whatever I wanted, but also that I would be nuts to try it.

Now I know that plenty of tanks have been built at home, and IIRC "ground and polished" is standard.

Anybody have a take on this?

Again, the guy was quite nice about it, and seemed knowledgable enough that I kept listening...

 

[Joel A]

OK, here's a new one. I called several suppliers today to request quotes.

One sales rep I spoke with stated that the polished edges would be terrible for adhesion and not to try it at all. We talked for several minutes and he was quite nice about it, and said he would happily order whatever I wanted, but also that I would be nuts to try it.

Now I know that plenty of tanks have been built at home, and IIRC "ground and polished" is standard.

Anybody have a take on this?

Again, the guy was quite nice about it, and seemed knowledgable enough that I kept listening...

put nicely, he was wrong.. flat wrong . Maybe it's the case for some other glass applications, but not the case for a fish tank. He's likely never built a fish tank before...

If the edges aren't polished or ground they wont be as square either, likely leaving voids in the silicone. You can get away with more "raw" edges on the interior, the edges that you wont see, but it certainly wont hurt to have them polished or at least ground. Of course i'm not a glass expert, but i've never read or heard anything about this, in fact i've heard the exact opposite. I personally would only polish the visible edges though, which are the edges that don't really need to adhere to anything anyways?

I had a guy at skiptons that seemed knowledgeable try to tell me that a supermale lineatus fairy wrasse, was actually a Super male golden rhomboid wrasse. I knew right away he was wrong, so i said "i think that's a lineatus wrasse actually"... stumbling he said "no, it just looks different because it was collected someplace else, They come from Figi and Australia, this one is from Figi and the other ones we have are Australian.." not wanting to argue about it i let it go.. but the truth is that it was a lineatus, and to compound things Golden Rhomboid wrasses only come from one location in the whole world, and it's not Figi or Australia, it's the Marshall Islands.

Just my $.02

 

[JayM]

I think Joel nailed it John.

If you're concerned about ground and polished, look at Dave's 560....about as scary and big a tank as you'll see 'home made'.....and I bet it was nearly all ground and polished edges.

 

[JohnK]

Hehe, I was telling the glass guy about Dave's tank. It didn't sway him though.

 

[Dave McReeferson]

Silicone is amazing stuff, there is no doubt about it. Just about any other adhesive out there flat out requires a roughed up surface for proper adhesion, not so with silicone. A properly cleaned joint between two polished edges with good quality silicone is virtually impossible to pull apart without breaking the glass. It doesn't matter whether your edges are polished or not, if the bonding surfaces are clean, silicone will adhere with a vengence.

The guy was wrong.

 

[JohnK]

Cool. That's what I was thinking, this guy just seemed awfully convincing. I bet he's done just about everything possible BUT build a fish tank.

He actually said "well, if you build it and it doesn't leak, I want to come over and see it". I might just send him an e-mail when it's up and running

Anyway, I went ahead and built it today. We'll see how the water test goes. Pics coming.

 

[sciknen]

Hey if you don't mind can you give us the cost breakdown when finally done with the build..Where did you end up getting it from?

I really want to build almost the same tank as that.
Thanks alot

Dave are you going to be building a smaller tank? Also wheres that calculator you used Dave?

 

[jprince]

I had Portland Glass grind & polish the edges on the panel I used to repair the broken 200 I picked up. If the edge is going to be viewable, then I would have it ground and polished for asthetic reasons only. like Dave said, silicone will stick like a mother regardless.

 

[Cherokee_Dude]

How much to have the edges ground and polished? Trying to calc. the cost if I decided to replace a few panels.

 

[JayM]

Cool. That's what I was thinking, this guy just seemed awfully convincing. I bet he's done just about everything possible BUT build a fish tank.

He actually said "well, if you build it and it doesn't leak, I want to come over and see it". I might just send him an e-mail when it's up and running

Anyway, I went ahead and built it today. We'll see how the water test goes. Pics coming.

Well?

 

[JohnK]

Well the water test didn't go so well