Building a 75g all glass tank

[scolley]

Originally Posted by plantbrain

But perhaps if you go in with some other local folks for a pallet shipment, you can get a better shipping deal.

Up in the Northeast, where we have no local access to such products, that is indeed the way to go. A bulk order can drop those per unit shipping costs dramatically. If I had had other people to go in with me on a buy, I would might have bought. Not sure though, as the would not have given me the non-tempered bottom that I was dying for (for bulkhead drilling).

[Khandurian]

Hi scolley,

I'm looking for some clarification on the GE RTV108 please. Is this the stuff your talking about?

[scolley]

When I was using it I wanted it in caulk gun sized tubes - so I've not seen those exact tubes. That looks like the stuff though. It says RTV 108 on the tube.

Also, when I was looking, I think I recall only seeing it in the colors BLACK and TRANSLUCENT. I got the latter, and found that it does not mean clear, but it is rather semi-clear. A little you can see through, but a thick bead will dry to look whitish. The BLACK I assume to be just that.

[Khandurian]

Hey folks, Just wanted to let ya'll know that I attempted something close to what Scolley here has done.

He started with all new glass. I started with a 55gal found on the side of the side of the road with both sides blown out. Now, my seams are not as pretty as his. But I did a good job of sealing this baby all back up!

You can read about it over at Fish Geeks!

My first attempt was a real downer, the tank leaked, albeit a very slow drip, but it still leaked. After reading over this thread, I got alot of good information and helpful tips.

I used GE RTV108. Simply due to the fact that I had 20 tubes for free! I am happy with the results being this is my first attempt to take on a challenge of this magnitude. Enjoy!

[scolley]

Hey! Congratulations Khandurian! And thanks for posting that link here. Maybe people see yet another example that it can be done!

It's a pretty good feeling when you get it right, don't you think! Job well done.

I'm amused by your difficulty with the bubbles in the seams. I had the same trouble. But I think I figured that out... think it has to do with the speed at which you squeeze out the silicone (fast is good), pushing out a wide bead (as opposed to swaying back and forth to make it artificially thick - needs do come out thick) and slowly tipping the glass up onto a side (not pressing is straight on). But I'm not sure. Just like yourself, as I went along my seams got much better.

Thanks for sharing. Tank looks great!

[KoiGuy]

Very impressive.

But for the average person, buying the AGA 75gal is cheaper & safer.

I like the plastic molding base & top.

$200 for just the glass & $170ish for an AGA tank @ the store.

Where would you get the plastic moldings anyway?

[aya7med]

thanks alot scolley

you made perfect and creative work

i hope to make like this but i need to gain alot of experince in this hobby

thankkkkks

[mcox]

A couple of questions...

Is GE RTV 108 and GE SCS 1200 safe to use? By that I mean, will the compounds used to make it leach in time out into the water and poison the inhabitants?

Anyone know what the Adhesion and/or tensile strength is for RTV 108? I can find that the 1200 series has a tensile strength of approx 485 psi, but can't find anything on the RTV 108.

I read somewhere that most of the strength in a glass to glass bond is in between the panels where glass touches glass and that the interior seam is mostly there for looks and some protection from compromising the glass to glass seals and likely some additional leak protection. That being said, it seems to me that having an additional bottom interior perimeter bracing using 2-4" glass might actually help prevent seal failure.

What are your thoughts regarding? Thanks mc

[greenleaf888]

scolley I seriously considered building an all glass aquarium, but ultimately decided against the idea. I found price wise it really wasn't much cheaper and depending on size, it can be a gamble to say the least.

I must say I find it interesting how so many people want a flawlessly seamless aquarium and the risk they are willing to take to achieve this. I for one wouldn't dream about making an aquarium without bracing, deflection equals bad news in my books. As for the silicone, I don't believe making such a fine bead is a good idea. Cosmetically I think very few people would pay attention, let alone appreciate such a fine detail, so why risk catastrophic failure? I personally believe one contribution to your initial failure was a result of trying to have such a fine silicone bead. DIY is all personnel preference however, and I must thank you for the in depth article and your attention to detail. Your finished product looks amazing, one of the best I have seen. And you defiantly did your research, I know I picked up a few intriguing tips.

If I were going to build an AGA I would build spacer blocks. You could make them slightly larger than your end pieces to achieve a perfect silicone seem with a nice consistent thickness top to bottom. I would also probably not use clamps, as you stated earlier you risk pushing all the silicone out of the seem with to much pressure. Also many articles I have read suggest that using tape is the best method, you only really need to hold it all together with light pressure while the silicone sets.

Anyways I thought I would revive this thread with my two cents, as it was a really interesting read. My big DIY project will be a 220 gallon glass plywood tank. I know many planted tank enthusiasts don't really appreciate glass plywood tanks and would much rather have a flawless glass box which is very attractive, but for me it's an issue of what is more reliable and practical. Besides that I am a carpenter, so a glass plywood aquarium is right up my alley.

[scolley]

Originally Posted by mcox

Is GE RTV 108 and GE SCS 1200 safe to use? By that I mean, will the compounds used to make it leach in time out into the water and poison the inhabitants?

Anyone know what the Adhesion and/or tensile strength is for RTV 108? I can find that the 1200 series has a tensile strength of approx 485 psi, but can't find anything on the RTV 108.

I read somewhere that most of the strength in a glass to glass bond is in between the panels where glass touches glass and that the interior seam is mostly there for looks and some protection from compromising the glass to glass seals and likely some additional leak protection. That being said, it seems to me that having an additional bottom interior perimeter bracing using 2-4" glass might actually help prevent seal failure.

As far as the RTV108 being safe, all I can say is that once I finally got through to an honest to gosh silicone guru at GE, he said it was what aquarium manufacturers use. So IF I'm repeating that accurately, and IF he really knew what he was talking about, then I think it is a good assumption that it is safe for fish.

As far as the tensile strength is concerned... tensile strength is almost irrelevant. The cheap, over-the-counter "aquarium" silicone apparently have sufficient tensile strength. The issue is adhesion strength. Not tensile. And that is apparently where RTV108 shines.

As far as the bottom interior brace, apparently an additional layer of bottom glass is often used - maybe for the reasons you suggest. I honestly do not know.

Originally Posted by greenleaf888

scolley I seriously considered building an all glass aquarium, but ultimately decided against the idea. I found price wise it really wasn't much cheaper and depending on size, it can be a gamble to say the least.

I must say I find it interesting how so many people want a flawlessly seamless aquarium and the risk they are willing to take to achieve this. I for one wouldn't dream about making an aquarium without bracing, deflection equals bad news in my books. As for the silicone, I don't believe making such a fine bead is a good idea. Cosmetically I think very few people would pay attention, let alone appreciate such a fine detail, so why risk catastrophic failure? I personally believe one contribution to your initial failure was a result of trying to have such a fine silicone bead. DIY is all personnel preference however, and I must thank you for the in depth article and your attention to detail. Your finished product looks amazing, one of the best I have seen. And you defiantly did your research, I know I picked up a few intriguing tips.

If I were going to build an AGA I would build spacer blocks. You could make them slightly larger than your end pieces to achieve a perfect silicone seem with a nice consistent thickness top to bottom. I would also probably not use clamps, as you stated earlier you risk pushing all the silicone out of the seem with to much pressure. Also many articles I have read suggest that using tape is the best method, you only really need to hold it all together with light pressure while the silicone sets.

Anyways I thought I would revive this thread with my two cents, as it was a really interesting read. My big DIY project will be a 220 gallon glass plywood tank. I know many planted tank enthusiasts don't really appreciate glass plywood tanks and would much rather have a flawless glass box which is very attractive, but for me it's an issue of what is more reliable and practical. Besides that I am a carpenter, so a glass plywood aquarium is right up my alley.

Building yourself is definitely not always going to be cheaper. Shipping cost will make a big difference - if that applies to you as it did me. I had a special requirement - all glass, small seams, low iron glass, with holes drilled in the bottom. It was the last part that was the kicker. I would strongly suggest anyone buy a commercially built tank instead - if you can get one that fits your requirements.

Spacer blocks seem like a good idea. I've not seen it done though. As for tape vs. clamps, well that depends on how far you crank the clamp. And silicone is like grease on glass, and once that glass get's 1/2 inch thick, it gets heavy. It WANTS to slide around - big time. I believe all the tanks I've seen done with tape have been much smaller and/or thinner glass. I made a smaller tank with tape. It's easy with as small tank.

But if do it with tape, please post your results. Good luck.

[lemonlime]

I just wanted to thank you for documenting this project, a true legend thread on plantedtank. Inspirational.. I would like to do something similar one day.

[mcox]

I also want to thank you for documenting, let's keep this going and get as much opinion, tips, success/failures on here as possible.

[lostparadise]

All I can say is that fascinating article! and so thanks for posting it. I am very impressed with your tank..

[wendle]

Originally Posted by scolley

I'm amused by your difficulty with the bubbles in the seams. I had the same trouble. But I think I figured that out... think it has to do with the speed at which you squeeze out the silicone (fast is good), pushing out a wide bead (as opposed to swaying back and forth to make it artificially thick - needs do come out thick)

Some tubes just have bubbles in them, not much you can do about it. Sometimes they are just tiny little pin pricks. Sometimes they are like the size of an m&m and go "pop" and make the bead fall off the end of the nozzle. You can syringe a bit of silicon into these holes while assembling if they are really unsightly.

You _have_ to push out a wide bead in one go, running multiple passes is a recipe for disaster. Cut the nozzle to suit the thickness of your glass.

If you can't find the GE RTV in your area try for Dow Corning V2. It is just as good. I prefer the Dow product for black, it is "blacker".

[scolley]

My tank building adventure was one I would be a poorer man had I not gone through. And it is wonderfully gratifying to know that my documentation of this journey has helped other people! That was always my hope.

But with a few years separation from the build, and subsequent bust, of my tank, I have a few things that I am ABSOLUTELY convinced of. And that may be of benefit to you, if you are considering building a tank.

Chosing the right silicone is paramount. In this post, you see the thin seam that I used that was not RTV108. That seam - the one in the post - is the exact seam that burst the day after I spent time scraping the tank walls of GDA. That seam did not hold up to pressure. But the seams on the front of the tank did - those held with RTV108 vs. normal "aquarium" silicone.

Proper arrangement of the glass panes is critical.
In this thread wendle makes it clear that the sides of the tank should be attached to the bottom, as opposed to resting on the bottom pane as I did. While I had my reasons at that time, I'm convinced that they were wrong. Here is a wonderful post that illustrates why. So don't copy my design... have your side abut the bottom, not resting on it. Here is a post that describes why... That will maximize the holding properties of the silicone you use. And if you don't believe me, just look at my tank and see the multiple times mine had to be resealed at the bottom, and ultimately required immense seams to hold. Why? Because I made the mistake of putting my sides ON TOP of the bottom pane instead of ABUTTING AGAINST it as I SHOULD HAVE.


Hope this helps. Good luck with your tank building experiences. This was my first big one. But with what I've learned.... it WILL NOT be my last.