This one is being revisited for several good reasons. It expands on the adhesion of new and old, as well as exploring some new ideas. This round of testing of course raises more questions that can be explored later.
The myths:
1. New silicone will not adhere to aged silicone.
2. Silicone does not adhere to plastic.
3. Tanks left dry or outside will cause the silicone seal to dry out and decay.
4. One silicone is as good as the next.
I had on hand a case of my favorite silicone, Boss 310, for which I will be using to reseal a large tank that I have acquired. I also had two tubes of Plumbers Silicone and it turns out that both had set up without the metal seals being broken. The GE silicone has white pigment in it, however it should perform the same as the clear. There is not a distinction on GEs spec sheet for a difference between clear and pigmented silicone.
In the video that follows, the scale used maxs out at 10kg/22lb. The purpose of the test with the scale is to verify that the silicone bonds have respectable strength. The purpose of the Pull and Peel test is to 1. Determine if the bond between the old and new silicones will fail and 2. Determine if the old silicone will pull away from the tank (if it had degraded from being empty and in the sun).
It should be noted that I looked at several tanks before choosing one. The one I chose was the first one I looked at (the one on the top of the pile. The next two had peeling seams. They had seen commercial use and had been exposed to medications on a regular basis.
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The myths:
1. New silicone will not adhere to aged silicone.
2. Silicone does not adhere to plastic.
3. Tanks left dry or outside will cause the silicone seal to dry out and decay.
4. One silicone is as good as the next.
I had on hand a case of my favorite silicone, Boss 310, for which I will be using to reseal a large tank that I have acquired. I also had two tubes of Plumbers Silicone and it turns out that both had set up without the metal seals being broken. The GE silicone has white pigment in it, however it should perform the same as the clear. There is not a distinction on GEs spec sheet for a difference between clear and pigmented silicone.
In the video that follows, the scale used maxs out at 10kg/22lb. The purpose of the test with the scale is to verify that the silicone bonds have respectable strength. The purpose of the Pull and Peel test is to 1. Determine if the bond between the old and new silicones will fail and 2. Determine if the old silicone will pull away from the tank (if it had degraded from being empty and in the sun).
It should be noted that I looked at several tanks before choosing one. The one I chose was the first one I looked at (the one on the top of the pile. The next two had peeling seams. They had seen commercial use and had been exposed to medications on a regular basis.
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Cool. 
