ATM Al tubes: end rolling and wall thickness; was: Irrigation Tube Irregularities?

["Matt Tarlach" <matttarlach@jps.net>]

>Once the spider and mirror mount
were put in, they added some extra structural strength to the
tube (especially at the ends).....

Parallax and Hastings both offer end rolling...this would seem to be an
alternative to the door edge strips that's also supposed to add strength.
On the downside, rolling also reduces the effective id at the ends,
according to Hastings by as much as 1/2".  Anybody have their tube
rolled?...does it help, and how much is the id reduced?

Also, what wall thickness would y'all recommend for two scopes my friend and
I are working on:

6" f8, which will have an 8" od tube unless you can convince me that 7" will
not have problems with tube currents; choices are .050", .064", .074"

 and 10" f6, which will be in a 12" od tube, with either .064" or .094"
wall.

Thanks!

-----
Matt Tarlach
Carmichael, CA
matttarlach@jps.net