Best Aquarium silicone?

[cgoodman2003!]

Hey all,

So as I’ve posted in the past, recently my 65 gallon spring a leak on the bottom panel. Now obviously I’d like to solve this head on as opposed to spending more money I don’t currently have on a new tank.

With that said, I tried recently resealing the tank with the brand “Loctite”, an aquarium safe silicone. I waited the proper cure time and all, yet the panel still leaked.

With this all in mind, I come here asking for recommendations—do I try another brand (if so, please let me know what brand to try!!!)? Or do I go for another tank? Let me know, I’d love some responses and opinions!!

 

[Aquavaj]

How did you reseal it? Did you just put on a new bead over existing silicon at the seams? Or did you razor blade all the old silicone and then apply?

 

[cgoodman2003!]

How did you reseal it? Did you just put on a new bead over existing silicon at the seams? Or did you razor blade all the old silicone and then apply?

I razor bladed the old silicone then reapplied.

 

[ISpeakForTheSeas]

Here are my two cents from back when I was researching the topic:

I don't know that one silicone sealant is really any better than another - as long as they're aquarium safe, they should be fine. The one's that I see recommended the most are ASi Clear Aquarium Silicone Sealant, GE Silicone 1, Momentive RTV100, and Aqueon Silicone Sealant. Basically, as long as they don't contain mold inhibitors (like GE Silicone 2) or other toxic ingredients, and as long as they aren't expired (I've heard some horror stories about people buying expired silicones), they should be fine. Supposedly, GE 1 and RTV100 may contain small doses of toxic material, but I can't say of heard of anyone having problems with them, so take that with a grain of salt. Regardless, personally, I would say to go with either Aqueon or ASi.

The recommendations that I've seen for the silicone are ~1/16" or 1/8" - some people use toothpicks as the spacers (the average toothpick is just slightly larger than 1/16"), others use silicone spacers.

You inject the silicone into the gap left by the spacers. You'll need/want some kind of caulk gun (automatic caulk guns are used by the professionals because they are easier and more consistent, but they're really not necessary for hobbyists building one, normal-sized tank). Line the tank seams with painter's tape prior to applying the silicone to help prevent excess silicone on the glass, and run either the back of a spoon or a finger tip over the silicone in the seams to push the excess onto the tape and clean up the look of the silicone in the seams - remove the tape before the silicone dries (in theory, this should give you the cleanest looking lines).

it is possible to make it yourself, but it’s not always easy to build well or make it look clean (with glass, you need to do a good job with the silicone to make it hold; with acrylic you need to do a good job with the solvent; in both cases it’s typically a long process, and if you mess up you basically have to start over or risk the tank failing). That said, it’s doable, it’s just strongly recommended that you practice with scrap pieces before trying to make the tank

 

[cgoodman2003!]

Here are my two cents from back when I was researching the topic:

So as far as the spacers go, do I just place those between the glass and tank bracket?

 

[ISpeakForTheSeas]

So as far as the spacers go, do I just place those between the glass and tank bracket?

The spacers go between the panels of glass (anywhere the silicone needs to be) - the silicone is either injected around the spacers while the spacers are left in the seam (not recommended with the toothpick method, but common even professionally if silicone spacers are used), or the glass is clamped in place and the spacers are removed prior to the silicone being added.

 

[Aquavaj]

So as far as the spacers go, do I just place those between the glass and tank bracket?

Since your previous reseal didn't work then next step is to take apart all panels and "glue" them back together. That's where the spacers come into play. They go between the panel joints to give a tiny gap to get the silicone into.

 

[cgoodman2003!]

Since your previous reseal didn't work then next step is to take apart all panels and "glue" them back together. That's where the spacers come into play. They go between the panel joints to give a tiny gap to get the silicone into.

So the only problem with that is my tank is not rimless. So in order to take it apart I’d have to remove the rim, which I’m afraid would shatter the glass

 

[Aquavaj]

So the only problem with that is my tank is not rimless. So in order to take it apart I’d have to remove the rim, which I’m afraid would shatter the glass

Yea that's going to be a problem. I haven't removed the trim before on those types of tanks but I've seen people do and they pretty much had to destroy it to get it off. That would be for both top and bottom. Not sure if the manufacturer sells the trim pieces separately either.

 

[Ironwill723]

Hey all,

So as I’ve posted in the past, recently my 65 gallon spring a leak on the bottom panel. Now obviously I’d like to solve this head on as opposed to spending more money I don’t currently have on a new tank.

With that said, I tried recently resealing the tank with the brand “Loctite”, an aquarium safe silicone. I waited the proper cure time and all, yet the panel still leaked.

With this all in mind, I come here asking for recommendations—do I try another brand (if so, please let me know what brand to try!!!)? Or do I go for another tank? Let me know, I’d love some responses and opinions!!

Momentive RTV 103 (black) or 108 (clear)

 

[Red_Beard]

you may have better luck with a silicon adhesive like RTV 103/108, SCS 1200 vs just a sealant eg GE if you are not going to remove panels and start fresh. This (SCS1200) is how i resealed my 75 6 years ago, no leaks. you have to scrape all of the seams in the inside clean, like NO RESIDUE clean, and scrub with alcohol until the glass is as clean as you can get it. Skin oil, chunks of old silicon etc will cause a weak bond and promote leaks. Silicon does not stick to cured silicon, so you have to do it all in one continuous go, no cold seams. Also, the more time you spend in prep, the less time you need to spend worrying.