Silicon problem

[ddoan]

I resealed my tank and let it cure for about a week. I just noticed the past few days that the silicon is coming off in little thin strips in the tank. What's going on? What can be doing this? I don't want to empty the tank and repair the **** thing.

HELP!

 

[WharfRat]

its possibly where oils from youur hand touched the glass and its not creating a bond or the glass was not prepped well before application. as long as you have a good fillet |_ <-----a convex of silicone flowing about 3/16 to 1/4 on the botton and upright glass you should be ok. If the silicone is peeling in this are you will have to try again. Its not adhereing to the glass and you put water in it...its going to rip that seal and you'll have a floor full of water. What size is the tank by the way??

 

[ddoan]

Okay, I've sealed the fillet with 3/16 of a bead. I have some concerns now. I have noticed that the the fillet has a hair like line that runs up it on all 4 corners. It looks like an air pocket. Anyways, is this a sign of stress? If it is, I am going to dump the tank asap tonight and reseal the fillets again, but with more silicon.

 

[WharfRat]

you should see -0- air bubbles in the silicone. Tear it down..cut the old stuff out..clean the glass with vinegar ( pure white) and dont touch the sealing surfaces. I always used surgical gloves to work on my tanks and I've built sizes from 30 gal to 125 gal with no troubles. make sure all side are square and plumb and that you have a good even 3/16 to 1/4 bead

 

[Mako]

finaddictfred, I appreciate your advice to ddoan, it helped me out as well!!


Ddoan, you can also, *just* before re-glueing, clean the glass with a paper towel soaked with isopropyl alcohol. Also make sure all of the old silicone is scraped off with a razor blade. I've also had people tell me, that on bigger tanks, they etch the glass ever so slightly-- barely visible-- with the razor blade (drag it flat-edged a handful of times where silicone will contact it) to make it bond better, but I cannot say I've ever done this myself.