[nikohak]

Does silicone need to fully cure before it is safe? And by "safe" I mean that it does not release toxic chemicals to water, not that it is strong enough to hold anything together.

The reason I ask is that I intend to use it as filler material and some of the silicone would be sealed maybe 1-2 inch deep.
Complete curing times for such can be measured in years, I guess.


I am using Bostik Glass Silicone that is graded aquarium safe and does not contain vinegar acid.

 

[deeda]

I think your best option is to email or contact Bostik for a response for this particular question.

If your plan is to fill in large or deep gaps in a DIY background or assembling rocks or other structures, your best choice may be a spray can of Pond Foam sealant.

 

[nikohak]

Thanks. I'll let you know what they answer.

 

[nikohak]

The guy at Bostik said that Bostik Glass silicone cures 1-2mm per 24h. But did not want to specify how this is with thicker pieces. He said that it must be completely cured before it can be placed in aquarium.

So I think I'll play it safe. I've actually used Apoxie Sculpt for attaching the rocks and I think I just order it more. It's expensive, but really easy to work with.

 

[deeda]

Thanks for posting back the comments, I figured they wouldn't be able to give you an exact answer due to the thickness you were thinking of using. Curing times are usually dependent on the bead thickness and environmental conditions and I've noticed that an overly thick bead wouldn't cure when used as a gap filler when I caulked exterior window trim.