Can I Seal A Tiny Leak From The Outside?

[nLinked]

I have just finished a repair where about 6 inches of the bottom of the seam was leaking. I filled with water today and there is still a tiny leak, about a drop every 5 seconds. Can I empty the tank, and seal with aquarium silicone (Bond-It HA6) from the outside once dry and clean? Will this work? Any tips?

 

[D4n.gr33n]

I have just finished a repair where about 6 inches of the bottom of the seam was leaking. I filled with water today and there is still a tiny leak, about a drop every 5 seconds. Can I empty the tank, and seal with aquarium silicone (Bond-It HA6) from the outside once dry and clean? Will this work? Any tips?

if your going to empty it then you might as well do the repair on the inside

 

[OldMan47]

There is no way I would ever try to seal a tank from the outside. Look at the reality of the situation. Water is trying to move from the inside to the outside. If it can move something aside to leak out, it will. If you seal from the outside you may have minimal success but you leave yourself in the situation of having some pressure trying to move aside your seal from the inside and you are relying on the adhesive qualities of your sealant to prevent that. Now look at an interior seal. The water in the tank is trying to force the sealant through the gap between your glass pieces in order to leak out. Even if you have a less than perfect seal, it will hold just fine for many years. If you take the time to first remove the old seal with a razor and then apply the new one, you will have a very strong seal, acting in the right direction, to prevent any leakage. It is a situation I would much rather have in my own tanks.

 

[nLinked]

Advice taken, we have completely stripped out the old seal from the inside and applied new. Just waiting for it to cure!