What is inside those walls?

westend...any idea what the spacing is on the studs ( 12, 16, 24, random )?

You could also use Oscar rivets, a special type of pop rivet that expands behind the wall finish. Very good holding power and can go into an exterior wall as they are only 1" long. Oscar rivets

If you have a shelf with a skirt or ledger, you could attach the shelf by fastening into the studs of the trailer with a sheet-metal screw.

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Have you considered 3M VHB tape? Expensive, but it is holding many solar panels on the roof, mine included. Various widths are available. I have also used it on lighter-weight applications, and it works very well. Nothing has fallen off.

On the flip side, if you use Z-brackets to mount your shelves, you could put two screws in the wall for each bracket. More support that way. Or, get the hook-and-plate mounts (I have a pair holding up a cabinet on the inside of my trailer). Each mount has 4 screws. That gives a mostly-down force on the mounting brackets, so they are stable.

Just my thoughts.

riven1950 wrote:
Wondering if the wall is filled with foam or whatever. I know the interior walls are open like a mobile home, fabric covered paneling. Have some butterfly toggle hangers that will work if it is open but I am thinking there would be foam in the outside walls.

Styrofoam-filled is most likely and file my RVS I prefer these, 1" long.

Thanks, forgot to say mine is a 2007 if that matters.

I mounted a shelf next to my bed using a fold down mechanism. My wall was just the wallboard, maybe 1/4" thick. I used the toggle anchor bolt, which I think you're describing, just long enough to make sure it caught. There was at least several inches of hollow space between bedroom and bathroom walls, both of which are internal.

Mine has foam in the exterior walls. I suspect yours does too.