Adding Silicone for Support?

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spitz006

Piranha
MFK Member
Dec 25, 2010
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Allegan, MI
I'm getting ready to buy a used 100 gallon saltwater tank and I asked if there were any leaks and they said "no leaks, but I would recommend adding some silicone for extra support because it's wearing out"

Is that realistic just to add silicone on top of old silicone? Sounds sketchy. I do not want to get involved with any re-sealing projects whatsoever. What are your thoughts?
 
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they sent this picture. What do you guys think? Cut away some of that excess and add new? Or do you think it's fine as is?

silicone.jpg
 
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New silicone does not stick to old silicone.
Right on ... I thought so. What do you think about just filling it as is? That kinda seems like its' just the excess silicone covered in algae, not necesarily something that needs to be repaired/replaced or whatever.
 
The structural silicone between the panels of glass is, at least in your picture, in perfect condition. That concave bead on all the inside seams is just an insurance policy against leaks; it doesn't add to the strength of the tank and only serves to maintain waterproof integrity if that structural layer isn't perfect. So, if you can inspect the entire tank to your satisfaction, well...it's your choice.

If that were my tank, it would be going into my unfinished basement, it would be placed on a tank stand that was carefully made level and flat, and I personally wouldn't worry about it...but it's not mine. :)

If you want to reseal it, you need to work all the way around all the interior seams with a razor blade, utility knife, etc, removing every trace of silicone from the interior of the tank but WITHOUT slipping in between the panes and damaging the structural stuff. Then you can run a replacement bead all the way around the interior, all at the same time, to reseal it. That works because the new silicone is adhering to the freshly-cleaned glass surface, rather than to the old silicone.
 
The structural silicone between the panels of glass is, at least in your picture, in perfect condition. That concave bead on all the inside seams is just an insurance policy against leaks; it doesn't add to the strength of the tank and only serves to maintain waterproof integrity if that structural layer isn't perfect. So, if you can inspect the entire tank to your satisfaction, well...it's your choice.

If that were my tank, it would be going into my unfinished basement, it would be placed on a tank stand that was carefully made level and flat, and I personally wouldn't worry about it...but it's not mine. :)

If you want to reseal it, you need to work all the way around all the interior seams with a razor blade, utility knife, etc, removing every trace of silicone from the interior of the tank but WITHOUT slipping in between the panes and damaging the structural stuff. Then you can run a replacement bead all the way around the interior, all at the same time, to reseal it. That works because the new silicone is adhering to the freshly-cleaned glass surface, rather than to the old silicone.
Thank you so much for your reply. It’s going in my unfinished basement too, on a stand that I will use shims to level out. Thanks again.
 
I'm getting ready to buy a used 100 gallon saltwater tank and I asked if there were any leaks and they said "no leaks, but I would recommend adding some silicone for extra support because it's wearing out"

Is that realistic just to add silicone on top of old silicone? Sounds sketchy. I do not want to get involved with any re-sealing projects whatsoever. What are your thoughts?

If the silicone seals are visibly bad like that than its definitely worth taking the time to strip the seals completely and reseal the tank before setting it up.

"adding silicone" will do nothing to strengthen the seals. The fact the owners said something like that leads me to believe it's a leaker.
 
Yeah its not terribly difficult, just use a blade razor and work one side at a time. You shouldn't need to separate the glass unless its visibly bad below the mess you got there.
Take your time with it, its not unlike caulking a shower stall.
 
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