[Daniel12490]

Hi Everyone,

I found a used 180 on craigslist with a wooden stand for only $175. Too good of an offer to pass considering how much these cost brand new. However, I do have some concerns with the silicone since the tank looks to be well over 10+ years old. With that said, I have never resealed any aquarium before. I would love to reseal this tank but do not know what type of silicone I would need and am afraid that I will seal it and then my tank will just explode when full into 4 different pieces. Any advice on how to seal it or experiences you guys have had while sealing a tank?

 

[Bushkill]

Your LFS should have a tube of "Aquarium silicone" as well as the pet box stores. Don't attempt this with a bunch of the squeeze tubes. It's the 10 ounce size that's designed for a caulking gun. You can also mail order, but shipping will most likely get you back to the same cost.

Aside from that all you need is a bunch of fresh straight razor blades, some painter's tape and a caulking gun.

Remove all of the old silicone with the razor blades. After you think you're done, at least run your finger over each of the old silicone beads. Then shine a small light source over them to make sure there isn't any residual haze. One last pass with fresh blade in each corner would be a good thing to do, even if it comes up clean.

Tape off each silicone bead 3/8" from the corner on each side. The bottom beads don't need to be taped off (nobody will see them). Apply the silicone and run our finger over it in one continuous movement. Remove the tape while the silicone is still fresh. Don't over-apply the silicone as it will make a sloppy mess that may end up beyond the tape. Practice on some similar objects would be a good thing.

Let it cure for about a week to be safe in a room with as little humidity as possible.

Re-sealing really doesn't affect the structural integrity of the tank. It's the razor thin inner silicone bead between the panels. THAT should be inspected for air pockets or signs of stress and separation.

Good luck. That is a good deal and 10 years old isn't ancient. I got mine about 8 years ago now and it was much older than that when I found it.

 

[Daniel12490]

For the razor thin inner silicone bead between the panels, what exact signs should I be on the lookout for?

 

[Bushkill]

Air pockets.

If that inner silicone bead has been stressed at any point and starting to tear apart, it will appear much lighter to almost white when compared to the fully intact seams. A leak test should also be part of this process. It's your call, but if you didn't see the tank filled when you bought it, consider a leak test both before and after re-sealing.

A good reference point are the silicone beads in your current tank. They should be near-invisible on a sound tank.

That silicone bead really is razor thin. A razor barely fits between the mating glass panels. I just tore down a couple of 15G's I got for free to use for glass tops, and it's a real struggle to push a razor through. But that's not where you want to be right now.

 

[Daniel12490]

Thank you, that is good to know. Even better to know that I cannot wedge a blade in there accidentally. Will I need a special type of silicone for a larger tank since there will be a fair amount of pressure?

 

[Bushkill]

You only really need to go to stuff like Momentive if you tear the tank down. It has a higher sheer strength than most other formulas. For a re-seal there's no need to use anything other than standard aquarium silicone. The GE sealants may work, but they've been re-labelled so many times now I don't know which is aquarium safe anymore. But the GE's aren't appreciably cheaper anymore either. For a few bucks more, why take a chance on picking up the wrong tube.

 

[Nlewis]

GE silicone 1 is what I've used to reseal 4 tanks.