3) Pure butyl tape.
The most expensive but the best choice. It sticks very well to all surfaces, never hardens or crumbles and remains pliable for years. And its a bear to remove. That's a plus, not a negative.
Correct. Sika Corp makes the butyl tape that major corporations specify for their applications. Insider knowledge so I cannot name them but Appliance and Automotive companies use only Sika. Another domestic manufacturer is located in Minnesota and theirs would work too. Butyl tape is not supported by any membrane. It's an industrial strength putty that will last for years as long as it is sandwiched between 2 surfaces.
Greg