Don't get me wrong, IMHO, 3M 5200 would be a very good choice. It's just important to know that it is irreversible. It's also important to know that 5200 cleans up with mineral spirits. Mineral spirits can turn one messy job into one very nicely finished job. Just don't over do it.
Eternabond is a very thick, very sticky material that is used for commercial roofing. I have never heard anyone that has regretted using it.
The roof of our apt building is actually done with the same material.
