So the aluminum channel on the perimeter of the roof wasn’t going to make this as easy as I’d like. There isn’t a lot of material above the slot to get the screw into:
I installed the enclosure rails using the screws provided, but I wasn’t very confident that it would hold up long term. I did a good job of getting the screw in the center of the channel on this one:
But I didn’t catch this one my much:
Considering that these enclosure rails are going to get some stress, I figured something a little more study was in order. Brass toilet flange bolts will do the trick. They fit perfectly in the channel.
So the enclosure rails were supposed to be universal in that they had some rectangular and v notches cut in them that would supposedly clear most roof/support combinations. It was strictly cosmetic, but the cutouts that didn’t even clear anything looked like a hack job to me.
I added some aluminum flat stock to cover the cutouts, tightened down the nuts on the t-bolts and then installed some rivets on any of the visible screws holes I originally made. I can live with the way it looks now.