<a href=showthread.php?s=&postid=6978902#post6978902 target=_blank>Originally posted</a> by Ron R.
I used the GE 1 silicone. There is a GE II which you do not want to use because it has additives to make it mildew resistant.
It is easy if you prep everything. I pulled off as much of the silicone as I could using my fingers at first then I used a straight razor blade. Do not remove the glue that holds the glass panes together. Don't go sticking your razor blade in there or you risk the chance of compromising the strength of the bond there. I used alcohol to clean the corners well. This removed every last bit of silicone and gave me a clean surface for the new silicone.
I used the blue masking tape you use when painting. It sticks, but not a strongly as regular masking tape and it does the job here. I ran the tape somewhere between 1/4" and 1/2" from the corner and ran it from the top to the bottom of the tank.
I got a good caulking gun and laid down a consistently thick bead from the bottom to the top. You don't want to lay down too little which defeats your purpose or too much which will get messy. Only do 1 corner at a time.
Using disposable gloves ( i guess I could have gone bare skin also) I wet my finger, pressed down on the bead and smoothed it out. You want to push down enough to be sure the silicone gets down into the corners, but not too much or you will be left with a thin layer of silicone. Some of the silicone will run over onto the blue tape....that's ok. I did my best to run my finger from the bottom of the tank to the top and only 1 time because this stuff gets thicker quick and tends to get sticky. I made the mistake of leaving my tape on for 1-2 minutes after this procedure and some of my silicone came up with it. I had to re-do my first corner twice. This is how you learn.
I lifted the tape immediately after smoothing down the bead and what you have left is a smooth silicone corner with straight lines.
This stuff smells to high heaven. It's a strong vinegar smell and you have to let it cure for 24 hours. You should not have any vinegar smell once it's cured. I let mine set for 2-3 days and then added my rocks, sand and water.
If you mess up and don't like the look, simply let it dry and repeat the procedure. I did a better job resealing my tank than I did re-caulking my bathtub. Priorities, the tank comes first. LOL
