Originally Posted by musigenesis
Could you do up a diagram of this like mine? I've seen pictures of parts of the Thomas chair rails but I can't really conceptualize how that structure works. It certainly sounds better and stronger than the International arrangement, which doesn't really have anything for allowing the cavity between the chair rail and the outer skin to drain (other than by overflowing which I think was literally the case in my bus).
To do the drawing justice (and this site as well), I will have to refresh my understanding by looking at the chair rail around the wheel wells. At present, the back of the bus is fully loaded up in preparation for taking another load to Florida. So this will have to wait.
After I send this post, I will look through the pictures I have on this tablet and see if any show it in enough detail. I'll post in the event that they show anything useful.