80/20 Rails on side of camper

[Oryguntroutbum]

Anyone with a newer camper or Project M with the factory 80/20 rails know if they are bolted through the frame or just sandwiched between the interior and exterior panels? I was at Mule Outfitters today looking and it looks like the bolts are pretty good size. Seems like they would seriously weaken the frame if they were run through it.
Thanks

 

[ramblinChet]

Another WTW member, Dessmo, has successfully installed airline tracks on the side of his FWC and has some nice pictures and information to share.