Sealants fail due to, improper choice of sealant, improper prep, improper installation, It is easier to properly clean out and off the existing sealant joints and reseal with eternabond tape system. Eternabond was installed on my aluminum roof center seam and the end caps along with stripping in the vents and penetrations in 1996 and the roof is still leak free. Works for me.
Learning more every day.
Pampered 96 Endeavor