[Narelle]

I am just finishing up building a big slate cave structure for my 55g tank's hardscape and used GE Silicone I to attach the pieces. Looking at the product's online information, it's supposed to cure in 12 hours, but I don't know if you cure longer for aquarium use? I looked through a bunch of posts on a variety of different forums and got pretty varied answers - usually anywhere from a day or two to a whole week.

How long do you wait for your silicone to cure? I don't mind waiting longer than necessary (I'd rather be safe than sorry), but a week seems pretty excessive, and this tank has already been pushed back for too long. So how long would you wait for it to cure?

 

[Darkblade48]

I wait 24 hours at the very least, but usually wait a full week to ensure it has completely cured.

 

[Bushkill]

I wait 24 hours at the very least, but usually wait a full week to ensure it has completely cured.

Same here. It can take even longer if the humidity is high where you're working. You have to keep in mind that the smell emitted while it's curing is acetic acid. So at the very least, a simple "sniff test" should be applied.

 

[Narelle]

Darn. Guess I'll be pushing all my plans back a whole week then. Completely forgot about curing the silicone when I scheduled it all out originally. Guess its a good time to get some other things done.

Thank you both for the help!

 

[jimbocurtice]

It will cure underwater, but it will take longer. I usually wait 24h but I did put it underwater after 2 hours and it did hold. If you don't have any livestock in it I would put it underwater, specially if it is not for something that needs to be water tight. Also for these kind of projects I usually use epoxy as it cure fast.

Sent from my SGH-I747M using Tapatalk

 

[lochaber]

I'd also probably use epoxy.

Anyways, I imagine it should be fine after a full day or so, as long as there aren't any really thick blobs of it. Might be worth rinsing off.

 

[burr740]

For a normal application (not a big glob of it) 24 hours. With livestock present I wait until it stops smelling like silicone, usually 3-4 days. Im not sure how critical that is, it's just what I do.

 

[sowNreap]

What brand or type of epoxy do ya'll use?

Some of my projects lately I can't wait for silicone to cure so have been trying to get by with my hot glue gun. Doesn't hold as good as I'd like on some things but I can put it back in the aquarium with the fish a whole lot sooner.

 

[skanderson]

the rule of thumb for curing silicone when building tanks is one day per mm of glass thickness. I believe that silicone cures faster with higher humidity.

 

[Narelle]

There are some thicker areas. Do you think I should just wait a couple more days or be safe and wait a full week?
The tank is empty right now, I'll be adding substrate, water, and plants once the caves are ready and then I'll be starting my cycle, so it'll be a while still before I can move livestock in.

I'm also curious about what kind of epoxy you guys use. I tried finding similar projects to mine and the closest I could find used silicone, so I figured that would work for me.

I'm using my silicone on slate tiles layered one on top of the other to try to build a more natural looking cave structure. The tiles are about 1/2 inch thick and don't always meet evenly, given that they're smashed and chipped up pieces of slate. I'm not sure how well tank building rules apply to a pile of broken tiles. ^^;;
The humidity thing should help me though. I live on the gulf coast of Florida.

(I'll add a picture in a little bit so you guys have a better idea of what I'm doing.)

 

[KhanQueso]

A bit late, but I asked GE about curing silicone for one of my current projects.

They said that silicone cures based on humidity (as skanderson already suggested). For gluing two pieces of slate together along an edge it should cure at the rate suggested on the bottle; I believe it is 24 hrs to be "fully" cured.

They do not recommend using GE I to glue large sheets because humidity cannot easily penetrate through the outer glue to reach the glue on the inside. See example below for clarification:

I personally have glued the "wrong" way without any problems. I just add a week to the cure time.

 

[Soothing Shrimp]

Just for interest, I just watched a Tanked episode where they were building a Hawaiian volcano. A bulb was sticking out the bottomof teh volcano, so they applied silicone on the job site RIGHT BEFORE they added water and introduced fish.

Have no idea what they used, but it blew my brains.