1incpa

You know, I've never questioned it. It was how I was taught, and what I've always done.

In fact, when I used to build Formica counter tops (which is pretty much the same procedure), I'd use 2 coats of glue. Again, it was how I was taught to do it. I never questioned it.

I can tell you that I've been using this method on my wife's cross tubulars, which she generally runs at less than 20psi, and she's never rolled one.
I got my front wheel crossed up once on the track and dragged it sideways so hard it tore a hole in the tire and cracked a spoke on a Hed tri spoke wheel. But it stayed on the rim.

Not trying to start an argument or say you're doing it wrong. This is just what's worked for me.
Paul

Edit: Mark got his reply in while I was typing...
Thanks for that explanation, it makes sense.
I generally deflate the tire after it's straightened out and roll a dowel around the circumference to make sure the center of the tire is seated on the rim.
PI