Electrical tape is only an insulator, doesn't 'contain' any electrical or RF radiation. It would be about like the fiberglass of that antenna, just contributes to mechanical things, has no affect on, is invisible to RF. You could tape up a typical antenna and see no change in how it would behave.
The problem with using electrical tape (or any other kind) is that it just doesn't last very long exposed to weather. The 'plastic' the tape is made from will react with ultraviolet and other emissions from the sun, either get stiff or saggy. The 'goo' that holds it to whatever is a far cry from 'permanent', and will fail. I don't think tape would be your best choice. But, it certainly will 'work' for some unknown length of time. If that's long enough, then that's certainly good enough.
- 'Doc