Is it possible that a change in barometric pressure has allowed a minute air bubble to expand?
As weather here has worsened barometric pressure usually drops.
No experience at all in this matter just trying to think outside the box.

I have some bubbles like this on my Concept built tank. I have never been happy with them but she hasn't sprung a leak yet. :wink:
Very nice build by the way

Thanks for the ideas guys!

I was just about ready to hurl myself off the roof when I had an idea!!

What if I just put steel vertical braces around the seams of the tank?? The top and bottom horizontal seams are well braced, it's just the vertical ones that worry me. To hell with the whole clean look I was going for... On a 10 foot span it wouldn't really detract from the view panels too much and that way I know it's not going to explode & drown the cats.

Thanks for the positive words Ram 3500! How long have you had the tank & what dimensions?

I would love to just make piece with the bubbles but there are multiple ones per seam and some are over 2 inches long. All of them in the middle (vertically) of the seams though.

If is not between the glass panels(the structural part) the you can cut out that portion and clean very well and reapply the silicon. It might be even from the fast reaction of the silicon, you sad the silicon start to skin in few minutes..

Unfortunately the bubbles / cracks happened in the structural portions... in the worst one (photo) I'd say about 50% of the 1/2" structural part is compromised, left to right.

I'm going to do the steel bracing idea, very happy with the thought of not having to strip these panels down again :)

The steel brace will hold it for sure.....

pretty sure its a clear silicone thing, any custom tank ive seen with clear silicone has bubbles like that

Thanks guys, makes me feel a bit better... I think I'm still going to go with the steel braces though, just don't trust this thing anymore.

Made some minor progress, we got the euro-bracing on!

https://lh3.googleusercontent.com/-X...0-Ic42/43b.JPG

A little hard to see, but I've got 4" of bracing running along the top perimeter and then three 6" braces running over the top, front to back.
Once the books, clamps and tape comes off I'll take some proper photos. Didn't want to climb inside the tank before everything's had a couple weeks to dry.

On a funny note, after putting the braces on I noticed the piece of MDF I used to stand on, inside the tank still. Lol, guess I'll have to chop it up to get it out. Somehow I always knew I'd forget it in there. MDF make good aquascaping? lol

5 More tubes of silicone on the way... This puts the count on 24 tubes and I'll probably need more before the overflow's done. This time I'm going with SCS 1200... half the price and free shipping with some true union valves and clear netting I found online. From the info I could find online it looks like it's pretty good at adhering steel to glass as it's a industrial glazing adhesive. Doesn't stick to plated steel though unfortunately so I'll have to do a lot of prep work on the steel angles once I find 'em.

On the topic of silicone, when you google GE SCS 1200 silicone and open the official spec sheet, the logo on the top of the document says "Momentive". GE has been licensed and trading under Momentive since 2006, so it's either the same or close to the same stuff I've been using... just cheaper and more readily available!

Thanks guys! Had a slow weekend with some family related travels but made some headway...

https://lh3.googleusercontent.com/-P...00-Ic42/48.JPG

https://lh3.googleusercontent.com/-S...00-Ic42/51.JPG

Still some scraping and cleaning up to do but most of the bracing's been cleaned up. I'm still hesitant to climb inside or un-clamp the base as the seam there is well over 1" in some places and the silicone takes 7-14 days to cross link and cure proper. Can't wait to get all that tape out of there!

Meanwhile I've started unpacking some of my dry rock, you can see some under the stand. That one piece measures around 30" across:

https://lh3.googleusercontent.com/-r...00-Ic42/47.JPG

I also got my hands on some more Seaflor special grade sand, so I have five 40lbs bags in total which should get me a 1" sandbed. I hope :)
At $50 a bag I've already started running out of beer money over here.

Great looking tank!!

My buddy at Oceans by Design in Seattle, WA builds all his custom tanks using Momentive SCS1200. It's an adhesive silicone and not just silicone.