sticking viewing glass to concrete tank?

[mad ness]

hi.

have read through several posts on concrete tanks similar to one Im building.

have posted a seperate thread on the silicone itself.

question for sealant on the bottom side of glass:

Im thinking the weight of the glass will press much if not all the silicone out of the bottom side. Is this a concern and if so is there a method to this such as spacers?

thank you.

 

[spiff]

It can be done either way. I did mine with no spacers on a wood frame. Even if it smooshes all the silicon out from under the bottom edge, there should be enough trapped to seal. If not, then there is always the facing side and the inside. The primary seal should be the inside anyways.

 

[mad ness]

thanks for the reply. did you apply the glass edge, inside/outside all at the same time?

 

[spiff]

I used acrylic, which is inferior to glass in terms of silicon sealing to it. But no, due to design complications with two windows meeting at a 90 degree angle and other issues, the biggest window was done in two stages separate from the smaller window. So its possible to do it in stages, but I think you're better off if you can do it all at once since silicon usuallly won't stick to itself.

But I sealed the largest window first, on outside edges only. Then I followed up with the 2nd window, both sides and then the inside of the largest window. In fact, I had to remove the smaller window after a leak and then reseal it, even though all the beads from both windows meet. Luckily this worked.

 

[mad ness]

alright cool, thanks for the tip. going to take a while to dry but doing all at once is the better way.