Silicone over silicone question

[Jeepjeep_0]

So I know the general answer to this question that silicone WONT adhere to old silicone however....... I have a brand new tank I’m making into a sump and I need to adhere a sheet of glass all the way to the bottom of the tank. That being said I will have 2,1/2 inch contact points on the bottom of the tank where the two corners of my 1/4 inch glass meet the factory silicone. When I run my bead down the edge of the glass and then a 1/4 inch corner bead will the silicone not stick in the bottom 2 corners?

 

[Crabs McJones]

So I know the general answer to this question that silicone WONT adhere to old silicone however....... I have a brand new tank I’m making into a sump and I need to adhere a sheet of glass all the way to the bottom of the tank. That being said I will have 2,1/2 inch contact points on the bottom of the tank where the two corners of my 1/4 inch glass meet the factory silicone. When I run my bead down the edge of the glass and then a 1/4 inch corner bead will the silicone not stick in the bottom 2 corners?

If it's being used for a sump baffle it will be ok. If you were using it for a main exterior piece of glass its recommended to strip out the old silicone. But for a sump baffle it will be fine.

 

[Flippers4pups]

So I know the general answer to this question that silicone WONT adhere to old silicone however....... I have a brand new tank I’m making into a sump and I need to adhere a sheet of glass all the way to the bottom of the tank. That being said I will have 2,1/2 inch contact points on the bottom of the tank where the two corners of my 1/4 inch glass meet the factory silicone. When I run my bead down the edge of the glass and then a 1/4 inch corner bead will the silicone not stick in the bottom 2 corners?

Agreed, should be fine.

 

[WVNed]

It works fine. And later you can remove it and put fish in the tank again.

 

[Jeepjeep_0]

Yeah, kinda my thought. I’d hate to have a leak from one compartment to the other, but I’d also hate to cut out the factory silicone to put new silicone down.

 

[Jeepjeep_0]

I appreciate it folks, I’m just overthinking it like everything else. Gonna start a tank build thread later tonight, we started demolition in our family room on Christmas Eve to put a 180 in the wall. Final coat of Sheetrock mud is drying now so I have plenty of Time still to get my new 75g sump right.

 

[Crabs McJones]

Yeah, kinda my thought. I’d hate to have a leak from one compartment to the other, but I’d also hate to cut out the factory silicone to put new silicone down.

Water is going to be going from one chamber to the other anyway right? Doesn't matter if its over the top or in little crevasse on the bottom

 

[Jeepjeep_0]

Yeah so I think my “stolen” design is a little unorthodox. I’m going to have a fuge on one end getting about 25% of my tanks water and over flowing the top to the return pump. On the other end I’m going to have 75% of my tanks water entering through filter socks into large skimmer/reactor section, staggered bubble trap and overflowing to the return pump. So really my fuge side is my biggest concern to not leak into the return pump section and send potentially large particulate matter into my return pump. I think it will seal fine though, just needed you guys to boost my confidence a little.