I want to seal a seam. Will silicone even hold up on an existing surface of silicone?
In fact, silicone will not set properly on silicone, because bridging bonds cannot be formed on set silicone. Therefore, if you wish to reseal a seam, it is advisable to apply a broader layer of the Aquasil to the old silicone seam, so that the contact surface with the glass is large enough.