I just recently got a used 75 gallon tank, and the Silicone seal on the bottom edge appears to be eaten at by something. I am just concerned about the quality of the seal now. I had about an inch of water in it for two days, and I didn’t see anything leaking. If it is a problem, is there a way to fix it without resealing the entire tank?
Something eating/breaking down silicone seal
- Thread starter ChaseB143
- Start date
- Tagged users None
Dom
Full Time Reef Keeper
Sometimes, scrubbing algae from the glass can tear away pieces of silicon over time. Cutting it out and resealing it is ideally the way to go, but, it won't be a small job if the tank is already up and running.
How do I reseal it, would I have to remove all of it, including the silicone that is holding the glass together, or would I just have to scrape the stuff out that’s on the inside of the tank?
Timfish
Crusty Old Salt
To me it looks like someone already tried to reseal it. On the left side of the seal in the picture there's two straight lines that look like an original tape line and a 2nd newer tape line. The silicone also looks like it may be old and "dragged" or stuck to whatever was used to push it into the joint and smooth it. I wouldn't cut the tank apart but I would cut out the silicone from the insides of the joints and resilicone it as mentioned above.
Timfish
Crusty Old Salt
To me it looks like someone already tried to reseal it. On the left side of the seal in the picture there's two straight lines that look like an original tape line and a 2nd newer tape line. The silicone used also looks like it may have been old and "dragged" or stuck to whatever was used to push it into the joint and smooth it. Irregardless there's obvious air bubbles in the silicone I would not expect to see in a factory applied joint. It's probably ok and will hold water but resealling it would at least give you peace of mind and it's not that difficult to do. I wouldn't cut the tank apart but I would cut out the silicone from the insides of the joints and resilicone it as mentioned above.I . . . . ?
jtl
Well-Known Member
The silicone seams that hold the glass panels together have been compromised and I would not trust them. You can easily repair the inside seams but they don't really do much, it is more for aesthetics and perhaps a little protection for the structural seams. The correct way to fix this is to completely disassemble the tank, clean all of the seams and restore the surface to virgin glass, then reseal. This is not an easy job but it is doable. I have done this a couple of times when I messed up the seams in tanks that I was building.
LC8Sumi
Well-Known Member
Exactly. The main job is done by the silicone between the two glasses, and not the overhang of the silicone - no use redoing that & also silicone won't really bind to already cured silicone.
Also don't use transparent silicone on reef tanks, as most are not UV resistant & the spectrum of the light needed for our tanks will degrade it over time.
