Re silicone my 90

[oilfieldsafety]

Well I started putting my 90 together on Sunday and noticed that the previous owner has really chewed the silicone in the corners badly. If I cut out the existing silicone flush to the corner leaving the portion that is actually between the glass panes and replace the rest, will this still be strong enough? In the past on other types of projects I have noticed that new silicone didn't seem to bond well too previously cured silicone. Your thoughts / expieriences are appreciated.

Shane

[brizzo]

I have noticed that new silicone didn't seem to bond well too previously cured silicone. Your thoughts / expieriences are appreciated.

This my friend is a problem. I haven't personally resealed a whole tank, but when I was researching the subject I learned it's best to redo all the seams properly (rebuild from panes).

Maybe someone who has more experience can chime in on the issue, and what types of silicone for larger tanks (GE1200, RTV, etc)

[Mrfish55]

I have redone a number of tanks over the years and I don't rightly recall any enjoyable experiences. The key to a re-do is clean glass, it is a very labor intensive job and if you want it done correctly you would be best to completly disassemble and re-do the whole thing, the only real positive is it does give you the opportunity to replace the front pane with a scratch free or starfire panel and possibly polised edges for a high end look. If you insist and want to tackle the job you will need:
-flat work surface large enough to accomadate the tank
-rolls of paper towel
-box of razor blades
-masking tape (hold panels in place once glued)
-rubbing alcohol and 00000 steel wool (to clean the seams)
-heat gun (optional, if you heat the glass while cleaning it works better)
-cheap silicone spatula (I have found this to work much better than using a finger to tool the corner seams)
-tube(s) of silicone (I use GE brand silicone 1, do not use silicone II)
-friend to help as you need to work reasonably quick
-box of bandaids

Be sure to work in a well ventilated area. Good luck, have fun :biggrin:

[brizzo]

Then ... figure the costs for your time and materials versus buying a brand new trouble free tank :)

I once started to take apart a tank .. then thought about the above and went and bought a new one :lol:

[mark]

Was given a beat up 33g that I used to hold rock. Cut the silicone out only leaving where the panes butted together. Cleaned really well then reapplied the silicone.

After reading how hard it is to take apart a tank even after the fillet cut out, figured the structural strength was still there from the original undisturbed butt joint and the new fillet would protect the first, plus help seal. Used it continuous for about 6 month, then a few times since without problems.

[no_bs]

I would just strip the silicone out and redo it. You don't have to dismantle it. I have done about 12 tanks now with no problem's. My first tank was 4 years ago, and still no leaking, 135g with no centre brace. 3 days is a while for softies in a bucket,but do what you have to do.

[oilfieldsafety]

Well I thought that I should update this post. I ended up cutting the silicone our of the corners but left it where the panes actually but together. Then I scrubbed the glass with a scotchbrite pad and isopropyl alcohol, masked each joint and re-siliconed. The tank has been full now for a week, no leaks so far (knock on wood).