I am interested in a Porter-Cable random orbital 6" polisher 7424 (6
speeds). By switching the 6" backing pad with a 13700 5" sanding pad,
I can convert it into a 5" random orbital sander. By the look of its
picture with the sanding pad, it surely looks just like any other angle
sander. I am wondering whether I can use it to sand down a fiberglass
skin to taper its edge. Any idea?

Let me explain what I am trying to use the sander for:
I am going to lift the fiberglass skin of a deck, and then replace
the core material. After this, I need to put the fiberglass skin back
in place, and I am supposed to use fiberglass cloth and epoxy to bridge
the cut on the fiberglass skin. I need to sand and taper the two edges
along the cut in order to level the patch with the rest of the
fiberglass skin, and that is what I intend to use the sander for.

Of course, I also want to use it as a random orbital polisher. I just
want to know if I can also use it as a sander in the way that I have
described above.

Thanks in advance for any info.

Jay Chan