Why stop at a 150? I searched for the ad but didn't find it, but found this one-
http://newhaven.craigslist.org/for/1642797649.html
Resealing is easy. For me it's worth it if the tank is cheap enough. I've even bought busted tanks and fixed them.
If all this
doesn't sound like too much work then it could be worth it for you.
Things you need:
Razor blades, a box of them
Scraper/blade holder long handle for reaching the bottom easy
Box cutter
Acetone for cleaning before resealing
Masking tape 3/4" for sharp lines on your visible corners
Caulking gun
GE silicone #1 3-4 tubes may only need two but you don't want to run out
available from Home Depot or similar places
Spoon or your finger to smooth silicone
Paper towels
Here's how I do it:
Clean the tank!!
Then you need to cut out all of the old silicone. You want to cut it not pull it out. You don't want to remove it from between the glass unless you have a really loose pane. Go over every joint several times with a new sharp blade after you get the bulk of the old sealant out. You will still scrape fine sealant up even after it looks clean. You must do the entire tank, including around the bottom or it may not seal.
After all the silicone is removed use the Acetone to clean clean the corners to be sealed.
Using the masking tape, tape up your corners the width of the original sealant. This will give you clean lines when you seal it. You don't need to tape around the bottom, unless you plan on doing a bare bottom. The media will hide the bottom seal.
After its all taped up wipe the corners with Acetone again.
Now your ready to start with the silicone. You need to have a sufficient amount of time to finish sealing once you start. Once you start sealing you have to finish all the joints.
I seal the side corners first. Do one at a time seal it and wipe it smooth with your finger or spoon. After smoothing the corner pull the tape off, and do the next corner. Do not over wipe the sealant, you want to leave some behind. Make the sealant look like original. When all four corners are done, seal around the bottom and wipe smooth as you go around. Be quick, you don't want the silicone skinning over before you wipe it. Cooler temps will help slow the cure while your sealing it. Once your done sealing crank up the heat so it dries. I use my wood stove, 85* is easily attainable.
On a tank this size I would allow a minimum of 48 hrs or longer if your doing this in a cold garage, of curing time before water testing.
The smell of uncured silicone may bother some of the more sensitive members of your family.
