So I am going to recommend a bit of a different route with this, and some people are going to disagree and get pissy with me which is fine, it happens every time the silicone discussion comes up.
GE I and II that you can buy at Home Depot and Lowe's is a sealant, not an adhesive. The adhesive properties of it are so low that they are not even published. It is the same as silicone that you would find in a fish store. Crap silicone not designed to hold a tank together, they just repackage it so it says aquarium silicone on it. If you read the fine print it will still say not to use it for building a tank.
Now here is where everyone chimes in, but my tank/my friends tank/whatever tank was rebuilt using this and it has been holding xxx amount of time! Better your house than mine. I've seen enough tanks built using GE I and II you couldn't pay me to set up a tank built out of the stuff. It may be holding for now but it really is not the best for the job.
The silicone ALL of the big tank builders are using is Momentive RTV 103 or 108 depending on if you want black or clear. With a fish tank you want and need an industrial grade adhesive, not something that is designed to keep water out of cracks. It is a bit more expensive, about $12 a tube, but when you are spending hundreds or more on a tank what is a few bucks more to do it right? Grainger has the RTV silicone on their website.
Also, 36-48 hours for a cure time is not enough. The silicone may look fry on the outside after that time but a 1/4" silicone bead needs 2 weeks to fully cure. Silicone dries from the outside in. Filling the tank too soon can cause you a lot of issues.
I'm sure someone will argue with me saying it is unnecessary and that a lesser silicone will hold. And will it? Quite possibly. Is it the best or safest option? Not by a long shot.
GE I and II that you can buy at Home Depot and Lowe's is a sealant, not an adhesive. The adhesive properties of it are so low that they are not even published. It is the same as silicone that you would find in a fish store. Crap silicone not designed to hold a tank together, they just repackage it so it says aquarium silicone on it. If you read the fine print it will still say not to use it for building a tank.
Now here is where everyone chimes in, but my tank/my friends tank/whatever tank was rebuilt using this and it has been holding xxx amount of time! Better your house than mine. I've seen enough tanks built using GE I and II you couldn't pay me to set up a tank built out of the stuff. It may be holding for now but it really is not the best for the job.
The silicone ALL of the big tank builders are using is Momentive RTV 103 or 108 depending on if you want black or clear. With a fish tank you want and need an industrial grade adhesive, not something that is designed to keep water out of cracks. It is a bit more expensive, about $12 a tube, but when you are spending hundreds or more on a tank what is a few bucks more to do it right? Grainger has the RTV silicone on their website.
Also, 36-48 hours for a cure time is not enough. The silicone may look fry on the outside after that time but a 1/4" silicone bead needs 2 weeks to fully cure. Silicone dries from the outside in. Filling the tank too soon can cause you a lot of issues.
I'm sure someone will argue with me saying it is unnecessary and that a lesser silicone will hold. And will it? Quite possibly. Is it the best or safest option? Not by a long shot.
