resealing a tank

[robj6767]

Hi there, I just got my hands on a 75 gallon tank that was in rough shape with the seals. As i have never done this before with a tank, I'm looking for any help on tricks or information on how to do so. My main question is, do I have to seperate the glass and do the complete seal or can I strip off the old inside and then just reseal fromt he inside. The seal across the bottom of the tank seems fine and it is only the edges on the sides that are a bit old. The tank came from an aquarium and was already predrilled on the bottom, but the previous owner sealed that with a plate of glass. I don't have any worries about that leaking as its got a very good seal around it. What I do have a worry about is only resealing the sides. should I just reseal the entire tank or will the silicone adhear to the silicone across the bottom? If so, is a company called xiameter a good place for purchasing silicones online? I've heard good things about them but just wanted to double check.

[BigJim]

Welcome to AA!

Don't take the tank apart unless you have to. Get all the old silicone off the inside with a razor blade. New silicone will not stick to old silicone. Wipe the glass down with rubbing alcohol and run a new bead of aquarium-safe silicone.

That plate on the bottom would worry me. If it's not as thick as the bottom glass, it's too thin. I'd replace it with a bulkhead and plug.

[Todd2]

You do not have to take apart the tank. The silicone holding the glass planes in place acts as an adhesive. The secondary seam inside the tank acts as a sealant.

If the plate of glass covering the hole is on the inside of the tank (as I imagine it would be) rather than the outside and there is a good seal than it should be good to go.

Like bigjim said, if you are going to reseal it, you should redo all the seams inside the tank.

For silicone go to a big box store and buy GE window and door 100% silicone (This is safe for aquariums). Do not buy kitchen & bath. It contains anti-bacterial/fungal chemicals that will leech into the water.

[pat8you]

I would also go to your hardware store and pick up a caulk seam tool. It is just a little piece of plastic that has different shapes in the corners so you can get a clean looking seam. Just run it through your bead and it looks real nice.

[jsoong]

1. Do all the seams on the inside. If some of the seams are getting old & brittle, the others will be in the same shape. May as well do all the seams now to save you from having to tear the tank down & redoing another seam a year or 2 down the road.

2. Remove all the inside seams, but no need to take the tank apart unless a pane of glass is loose. Make sure you cut the seam off rather than pull so you don't damage structural seams. I find a sharp skew chisel much easier to work with than razor blades (no skinned knuckles) ... that is if you have one!

3. After cleaning all the area - remove all silicone, clean with vinegar for water deposits, then 100% iso-propyl alcohol, let it dry completely - tape the seams with masking tape.

4. After laying dowm the silicone (yes, GE 100% clear silicone door & Window without mildewcide is what I used) , smooth with a (smooth latex) gloved finger. <Seaming tool will work too, but fingers are cheap! Remove the masking tapes while the silicone is still wet (you have 10 minutes or so) and you will have a perfectly straight & tapered seam.

5. Wait 7 days for the silicone to cure, then leak test.

[Jimbo7]

Make sure you get GE Silicone I for windows and doors!!!!

We just recently had a thread about someone who ended up poisoning their whole tank due to the wrong silicone! Let cure for at LEAST 48 hours!

[alexloramer]

Yeah you certainly don't want to get the wrong type of silicone. Afterall, w're all trying to make good homes for our little fishies....or big fishies

[Greenmaster]

Originally Posted by BigJim

...That plate on the bottom would worry me. If it's not as thick as the bottom glass, it's too thin. I'd replace it with a bulkhead and plug.

I would probably go the bulkhead and plug route too but that is only because I would end up using the hole. As for the piece of glass covering the hole... it can be quite a bit thinner then the bottom glass as it doesn't need to cover the whole bottom just a 1-4" hole. I would just be a little careful about putting rocks/ornaments in the tank and make sure that nothing but substrate is put over top of the glass cover.