Finding a stud

Halibut214 wrote:
I see a few posts where people used a stud finder on the inside with great success but has anyone used one on the outside? I know I have aluminum studs but have no idea if it will penetrate the fiberglass and plywood to see the stud.
Thanks

I had to locate outside studs when I mounted the brackets on the side of my aluminum TT to hold my porta-bote.

I actually used a studfinder on the inside, and then very carefully transferred the location of the stud to the outside. I measured things like distance from the edge of a window, etc.

In one instance, I actually added a stud from the inside because there was no stud in a fixed location where I needed one. Then I covered it with wood trim.