Sealant question

AdrianBryce · 09/27/2009, 06:48 PM

I bought a DIY tank that someone else made about ten years ago. I know it holds water, but I came across something a while ago about certain sealants not being able to handle saltwater. should I be worried or is it cool?

SirusX1721 · 09/27/2009, 08:22 PM

has the tank been in use before?

AdrianBryce · 09/27/2009, 09:10 PM

yes the tank was used as fresh water, I believe the last time was about five years ago.

SirusX1721 · 09/27/2009, 09:29 PM

the tank may just need to be resealed as is. If it had fish in it at one point with no problems, and it held for this long it's probably fine. But IMO I would reseal the tank anyways. Not so much because the issue with the silicone type, but structurally. Who knows how strong a bond the old silicone may still have. Try and extensive water test...

uncleof6 · 09/27/2009, 09:31 PM

Quote:

Originally Posted by AdrianBryce

I bought a DIY tank that someone else made about ten years ago. I know it holds water, but I came across something a while ago about certain sealants not being able to handle saltwater. should I be worried or is it cool?

No silicone (commonly used for aquarium building) is for continuous use in water. (salt or otherwise.) There is a little catch to that though. The silicone-- that actually holds the tank together, is not exposed to water. It is protected by the sometimes quite large bead inside the tanks. This bead over time (not specified amount) does degrade (why tanks need resealing occasionally) and attacks the structural seam, creating a leak. (one reason a tank may leak at any rate.) check the structural seams of the tank for inconsistancies such as cloudiness, large amount of bubbles etc. This will indicate the condition of the tank. @ 10 years old, it is hard to say what is up with it, and should you worry, however I would give a good "check it out" before putting it in service.

Jim

AdrianBryce · 09/28/2009, 06:19 AM

So should I strip the current bead of silicone out and put in fresh or just go over the old strip?

uncleof6 · 09/28/2009, 11:18 AM

Quote:

Originally Posted by AdrianBryce

So should I strip the current bead of silicone out and put in fresh or just go over the old strip?

New silicone will not stick to the old silicone. So you have to remove the inside "sealer" bead completely, without damaging the "structural" seam between the glass panels. Once the silicone is removed, the glass needs to be cleaned thoroughly so that no silicone remains-- razor blades, acetone, elbow grease. It is a big job. Outdone only by a complete rebuild of the tank.

Make sure you use an FDA approved (non-toxic) silicone to redo the inside bead.

Jim

JTL · 09/28/2009, 06:04 PM

X2 for what Jim says. I would also suggest that you use fine steel wool with acetone. It really works good AFTER you remove the major portion with a razor blade. Another thing, buy a lot of razor blades they are only good for a couple of passes. You can get what appears to be all of the silicone off, but when you use a fresh blade the difference is noticeable. I never wanted to be an authority on cleaning silicone but practice makes perfect. I bet I could clean that tank in a couple of hours and a six pack.

There is someone on this board that may tell you that you cannot successfully reseal a tank, that person is wrong.

AdrianBryce · 09/28/2009, 06:28 PM

Thanks for all the help. I will give it a shot.

09/27/2009, 06:48 PM	#1
AdrianBryce Registered Member Join Date: Aug 2009 Location: Spring Hill, Tennessee Posts: 994	Sealant question I bought a DIY tank that someone else made about ten years ago. I know it holds water, but I came across something a while ago about certain sealants not being able to handle saltwater. should I be worried or is it cool?

09/28/2009, 06:19 AM	#6
AdrianBryce Registered Member Join Date: Aug 2009 Location: Spring Hill, Tennessee Posts: 994	sealant So should I strip the current bead of silicone out and put in fresh or just go over the old strip?

09/27/2009, 08:22 PM	#2
SirusX1721 TeeHee Join Date: Oct 2008 Location: PA Posts: 620	has the tank been in use before?

09/27/2009, 09:10 PM	#3
AdrianBryce Registered Member Join Date: Aug 2009 Location: Spring Hill, Tennessee Posts: 994	yes the tank was used as fresh water, I believe the last time was about five years ago.

09/27/2009, 09:29 PM	#4
SirusX1721 TeeHee Join Date: Oct 2008 Location: PA Posts: 620	the tank may just need to be resealed as is. If it had fish in it at one point with no problems, and it held for this long it's probably fine. But IMO I would reseal the tank anyways. Not so much because the issue with the silicone type, but structurally. Who knows how strong a bond the old silicone may still have. Try and extensive water test...

09/28/2009, 06:04 PM	#8
JTL Registered Member Join Date: Jun 2003 Location: Venice Island, FL Posts: 2,532	X2 for what Jim says. I would also suggest that you use fine steel wool with acetone. It really works good AFTER you remove the major portion with a razor blade. Another thing, buy a lot of razor blades they are only good for a couple of passes. You can get what appears to be all of the silicone off, but when you use a fresh blade the difference is noticeable. I never wanted to be an authority on cleaning silicone but practice makes perfect. I bet I could clean that tank in a couple of hours and a six pack. There is someone on this board that may tell you that you cannot successfully reseal a tank, that person is wrong.

09/28/2009, 06:28 PM	#9
AdrianBryce Registered Member Join Date: Aug 2009 Location: Spring Hill, Tennessee Posts: 994	Thanks for all the help. I will give it a shot.