Removing Old Silicone

[Spank]

Hello all!!

RIght I'm resealing some of the seams on my 2nd hand tank (bits of the old ones have gone brown and manky) and have started to remove some of the old silicone.

My question is how much of the old silicone do I need to remove? Parts of the seam look fine and I'm currently just scraping away the brown and manky stuff. Do I need to remove the silicone between the panes of glass? obviously this is a lot harder so if I do, how should I go about it?

Thanks for the help

Hank

 

[raptorrex]

Hello all!!

RIght I'm resealing some of the seams on my 2nd hand tank (bits of the old ones have gone brown and manky) and have started to remove some of the old silicone.

My question is how much of the old silicone do I need to remove? Parts of the seam look fine and I'm currently just scraping away the brown and manky stuff. Do I need to remove the silicone between the panes of glass? obviously this is a lot harder so if I do, how should I go about it?

Thanks for the help

Hank

http/www.fishforums.net/index.php?showtopic=42516 this will help.

though i fear it may be far more complicated, than just replacing the inside seal! new silicone is not good at sticking to old silicone. taking so much of the old silicone of, would leave a large area of weakness at the joint. i am no expert but that's what i think. perhaps the members with more experience will know better

 

[SkiFletch]

Agreed, you can get yourself into trouble by removing the inner seal and adding new silicone over the top of it. If you really want to tear the tank down and re-do everything you can try it. The best solvent for silicone (at least that's safe) is high-percentage ethanol. 95% Ethanol eats away at a silicone-glass bond REAL fast. 70% isopropyl alcohol (rubbing alcohol) is OK but pales in comparison to highly concentrated ethanol. Even something like 150+ proof alcohol would work well too, but it'd be a shame to waste on a tank

 

[Spank]

Agreed, you can get yourself into trouble by removing the inner seal and adding new silicone over the top of it. If you really want to tear the tank down and re-do everything you can try it. The best solvent for silicone (at least that's safe) is high-percentage ethanol. 95% Ethanol eats away at a silicone-glass bond REAL fast. 70% isopropyl alcohol (rubbing alcohol) is OK but pales in comparison to highly concentrated ethanol. Even something like 150+ proof alcohol would work well too, but it'd be a shame to waste on a tank

hehe, 150% proof would eat away my stomach lining real fast too, not just silicone!!

mmm, can anyone else help? I've removed a small 1cm length of silicone already but kept the bit between the panes intact but after reading this I don't think I'll continue.
I haven't actually filled and tested the tank yet so I'm not actually sure if the seams do need replacing, the brown and manky seams look intact but the edges of the silicone peel away quite easily All the seals between the panes of glass look fine.

I'm tempted just to re-seal the small area that I've scraped away and fill the tank to see if it holds..... but will this end in tears

 

[Tolak]

I would try replacing the small section, and see if it holds water. If the silicone is peeling at the edges, it's not going to be too long before it all needs to be replaced.

With questionable tanks I fill 1/3, and wait, a couple hours later fill another 1/3, and wait again. If there are seam problems this will help you narrow down the area where the leak is. If it holds overnight when full it is generally good to go, I've never had a problem doing this with any of my used tanks. I do this in the basement, so if there is a water disaster I only have concrete to mop.

Fill wit water that is around the same temperature as the room, cold water can cause condensation on the outside, making you think it is leaking.