Momentive RTV108 Underwater?

[MarsRover]

Hey everyone,

so i know a lot of folks use this adhesive for tank/sump building applications.

Has anyone used it for UNDERWATER applications?

The tube specifically says:

Limitiations: Corrodes copper, brass and sensitive metals. Not for use on stove pipes, fireplaces or under water.
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so.....does using it for aquarium glass NOT count as being under water?

I'm thinking about using it to glue my overflow box down to the inside of the tank....so i want to be sure i don't do something stupid here...

thanks

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[Even Further]

That sort of language is there to limit liability. Its proven to work great for glass to glass aquarium/sump baffle construction.

For an overflow box that is acrylic or other plastic, there's better products like GE silicone for plastics or Dow Corning 795. (both should cure properly before exposure to saltwater)

 

[MarsRover]

Excellent. Thanks!

 

[AlexG]

I agree this is a liability limiter. I used it on my large tanks because of its strength rating and well documented use for DIY aquariums. I would suggest if you have to put down a lot of RTV for building an aquarium that you purchase an electric caulking gun as there is a 10 minute skin time on RTV 108. For my tanks I had to lay down a thick bead that was between 20-22 feet long depending on the tank I was installing the glass fronts on and there is no way I could have done it before the skin time without an electric caulking gun.

 

[cromag27]

It means don't apply it under water.