Trying to reseal a tank.

Only thing is that it specifically says "for small aquariums" on the product description. A 55 gallon tank, while not the biggest out there, would stretch the definition of "small" in my opinion. I would go with the AGA from your LFS, for that same size tube it should not be more than 6-8 bux.

I did a lot of research and reading and calling of manufacturers when we repaired our 430. The different silicones are only rated to certain thicknesses of glass. 55 Gallon tanks' vertical panels are pretty thick . . .

 

To my knowledge, the silicone that does the sealing is only that silicone between the edges of the panes, i.e. the silicone that you can't touch. The bead that we apply afterwards (the one that we tool, or run our finger across) is just for extra security. Thus, if the pieces of glass were cut unevenly, or if it was a baffle that was cut too small; the joint would be larger than ideal and the silicone would have far less adhesion ability, weakening the joint.

That's interesting about silicone curing using moisture in the air. I never knew that.

 

And also - no matter what silicone you use, make sure you have a nearly unbearable vinegar smell coming from the silicone. That's how you know it's working and making Acetic Acid (i believe) from the moisture in the air.

 

dap 100% silicone is just fine to reseal a tank. just trying to do a patch job has never worked to well for me, i always had best results removing all the silicone (the cleaner the better ) and resealing the hole inside of the tank. i have done many over the years, in fact i just done a tank last week. and have never had a problem with any of them, including one of the 55s i have up and running now that i resealed a few years ago.

Real clean glass one bead of silicone and one wipe with the finger for best results. and a new trick i learned to keep the old silicone from sticking to everything when removing it and to highlight the spots you missed removing all the silicone, use a little baby powder on a paper towel to wipe the tank out,.... then wash let dry and then reseal .

 

Thanks fr the tips everyone. I just took another look at the tank. While the only part without a good seal is a small spot in one corner, I will still need to reseal the entire tank. As I got it used,it definitely wasn't in the best of shape. There's still dried algae (from a FW tank) that will not come off the silicone(even after cleaning & washing out the tank several times with 50/5o vinegar/water). I guess that will be my weekend project... ugh.

 

Seano. I would scrape off all the silicone if you can. new silicone doesnt adhere well to old silicone. if you have it that far apart, go ahead and redo it. thats what I did on the 225. just scrape it all off as best you can. Dont worry about the seams between the panes, just the corners. Scrape it down being careful not to destroy the seams between the panes. once completely scraped off, I mean ZERO RESIDUE, take some Acetone and wipe it to make sure there is ZERO RESIDUE left on the glass. you want PURE glass. then clean with Rubbing alcohol to make sure there are no oils. once you have prepped it, run you some blue masking tape about 1/4" out on each pane from the corner. this is your overrun guide so you get a perfect edge. once this is done, silicone away gettinga good bead in each corner and around the bottom. this will provide you a perfect seal as it is all fresh silicone with no seam between new and old. the better your prep, the longer it will last.

Dare to be Bold. you can do it. just get 100% silicone. no microbial at all. I ordered mine from Glass cages. got the black RTV silicone. Looks awesome and frames the tank. part of me wishes I had done my 180 in the black. Looks positively awesome.

 

OK entire redo it is then. Not sure if I want black or the regular clear silicone..

 

Go black. once you do you wont go back.

 

oh, that was the smell that got me high! Wow, I had my head in the tank so far I got a little loopy!

 

Gotta love it " Go black. once you do you wont go back" If Lisa Lampanelli sees that your in trouble!

All the info given in here is great, I have resealed tanks up to 250 gallons and I have completely rebuilt several using pieces parts from 3 different tanks.

But the MOST IMPORTANT thing that has been said here is "get it clean" buy a box of single edge razors and use the whole thing if thats what it takes. I have never used acetone but I use Alcohol all the time, either way make sure you get allot. You have to get every scape of silicone off all the while being careful not to cut the silicone between the two panels because as reefsparky said that is where all the strength in the joint is and if you cut that no amount of silicone you put on the outside will fix it.

Also pickupman66's idea with the painters tape works great, and you get a really nice straight edge. But I found that if you use the tape to get the best edge you will want to pull it off right away before the silicone has a chance to dry, that is the best way to get a nice clean edge.

Good luck