RTV rated silicone

[reefingit]

Hello,
Has anyone on here used RTV rated silicone on a running reef system?
I am contemplating adding extra bracing to my 93 gal Marineland cube as extra precautionary measure. It is a rimless tank and want to ensure that the added extra top bracing will help in securing any potential future bowing of the tank.
Just wanted to see if anyone has had any experience with this type of application on a running tank and what steps did you take to prevent any of the excess silicone from dripping into the water.
Are RTV rated silicone reef safe? I bought a tube that has a label RTV100 series.
Pls let me know. Thank you.

 

[143MPCo]

Momentive RTV100 series silicone is the way to go. It adheres to glass allot better than GE brand. RTV108 is clear, and 103 is black. Follow cure times as noted on the back. It'll look hard, but if you can smell anything it is still releasing chemicals. Once dried it should be completely safe.

 

[reefingit]

Momentive RTV100 series silicone is the way to go. It adheres to glass allot better than GE brand. RTV108 is clear, and 103 is black. Follow cure times as noted on the back. It'll look hard, but if you can smell anything it is still releasing chemicals. Once dried it should be completely safe.

Yes it is Momentive RTV108. My concern is since I will be applying this to a current up and running system, the chemical release might harm the tank inhabitants. I am hoping by doing one brace at a time and letting it cure, there is less chemical release before the next brace is applied.

 

[143MPCo]

Will the new silicone make any contact with the water at all?
Also silicone will not adhere to cured silicone, so depending on how you plan on adding the brace (one at a time) might be a concern.

 

[reefingit]

Will the new silicone make any contact with the water at all?
Also silicone will not adhere to cured silicone, so depending on how you plan on adding the brace (one at a time) might be a concern.

My plan is before I apply the new silicone, I will drain the water 1/4 of the way. Mask the inner and outer sides of the tank in case there are any excess silicone overflowing.
Then caulk the top of the tank where the new glass brace will sit. There will not be any overlapping of new silicone with the old.

 

[143MPCo]

https://www.momentive.com/products/showtechnicaldatasheet.aspx?id=10289

(1) Cure time 3 days at 25°C (77°F) / 50% relative humidity.

The cure process begins with the formation of a skin on the exposed surface of the sealant and progresses inward through the material. At 25°C (77°F) and 50% relative humidity, RTV102, RTV103, RTV106, RTV108, RTV109, RTV112 and RTV116 sealants will form a surface skin which is tack-free to the touch in 15 to 30 minutes. Once the tack-free skin has begun to form, further tooling of the adhesive sealant is not advisable. Higher temperatures and humidity will accelerate the cure process low temperatures and low humidity will slow the cure rate. As the adhesive sealant cures, acetic acid vapors are released from the sealant surface. The odor of acetic acid will completely disappear when curing is completed.

Maybe @Randy Holmes-Farley can chime in on the effects of acetic acid, but from what I've read, it's nasty stuff.

 

[Viper99ACR]

What is the difference with using RTV silicone vs. regular silicone (1)?

 

[143MPCo]

Assuming you mean GE 1 the stuff used for windows and doors? It doesn't have the strength adhesion of RTV, and if memory serves me is labeled not for aquarium use. DAP "Aquarium Sealant", by Dow Corning, is better, but is sold in small package when we require a tube. Momentive RTV103 and RTV108 (previously GE) and a few others are the silicones used tank building. RTV come in caulking gun tubes and makes for easy of use.