Union guy:
When pulling out the window etc. go slow and take care you don't damage your siding there is adhesion of the tape and suction at play here. I found a dull lineoleum knife gave me the best leverage and had a small footprint on the siding.
I've checked it out and this is what I found from Professional RV repair folks. Windows are butyl tape doors are putty tape the hatches look to me to be butyl. The Pros said they likesd putty tape for all of the applications. Also the suggested that small peices be cut the size of the dips in the aluminum siding and applied to the cleaned siding then an unbroken strip of tape either butyl or putty is applied to the cleaned frame of the window etc. and then fitted into the opening.
CAUTION: Use a plastic knife when trimming the excess so you won't hurt your siding.
