Silicone flaking?

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nicholsonsl

Aquarium Advice Newbie
Joined
Sep 17, 2008
Messages
7
About 3 weeks ago I dismantled and resealed the tank seen here:

http://www.aquariumadvice.com/forums/f59/newbie-w-28g-hex-106953.html

I used 100% GE clear silicone.

The tank has been full for about 2 weeks with no problems, but...

When running my finger across the inside seals yesterday, white stuff is flaking off the seal.

I seems like a thin layer of silicone is rubbing right off!

:eek2:
The seal is intact, but it almost seems like the top of the silicone is waterlogged and flaking off. This is impossible right!?

I'm praying that this is just something that is collecting along the seals and attaching to the silicone, that I just rubbed off. Is that possible? How on earth could the silicone be flaking off?

Anyone experience anything like this? I'm extremely worried.

There are no fish in the tank, but I'd hate for it to crash in my living room!
 
Which silicone did you use...exactly. The GE Silicone I - Door & Windows is safe.
I never saw silicone flake before, so I don't really have an answer for you.
 
Which silicone did you use...exactly. The GE Silicone I - Door & Windows is safe.
I never saw silicone flake before, so I don't really have an answer for you.

I can't remember if it was I or II, but that's the stuff. Got it from Lowes.

Premium Waterproof Window & Door 100% Silicone 10 OZ Clear

The fact that is says "impermeable" right on the side of it, makes me hopeful that this is just a fluke.

The flakey stuff is white-ish, while the silicone is clear.
 
It's most probably just the ultra thin layer that is on the outer edge of the silicone seal. It will rub off easily because of the thinness. No real biggie. It looks cloudy because the thin layer ends up being rolled making it more translucent than clear.

Best advice.. Stop rubbing it

BTW: I agree that you used the wrong stuff as well. I did too when I used it for some ornament stuff in my FW. For me, I never saw any ill effects but YMMV
 
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Yeah, that was a bogus link.

I definitely avoided the mold/mildew resistant stuff.

Good catch though!

I'm gonna keep an eye on it for now to see if it continues or gets worse.
 
Unfortunately, it looks like I did not avoid the mold/mildew resistant silicone. :n00b:

Gotta reseal... oh well. It's really not tough and the lesson is learned... and nothing died.
 
I have seen a recent post in another forum with the advice that silicone requires humidity but not moisture to cure properly. The stated best practice would be to use a thin layer as your sealant and then leave the tank empty for about a week for the silicone to get its maximum strength. At that point the water will have no effect on the strength. If it cures in a bone dry environment like you find in a desert or it gets wet while curing it will not be as strong.
 
I followed ccCapt's advice and resealed the tank. It has had water for several days now with no flaking.

I wonder if there was something in that mold/mildew resistant silicone that caused the strange film to develop.

I will keep an eye out, but everything is going well for now.
 
The last tank I repaired ended up with a white flaky build up on the silicone. Not sure what the cause was but looked like a mineral buildup, that nws flaky. I cleaned it off and it hasn't returned. Never saw that happen before. This is the same silicone I have always used,to do more than a dozen tanks.
 
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