: 6063-T6 in 20mm X 1.6mm should be fine. The Argentine Sea Cruiser in the link
: below is constructed of 6063-T6.

: http://yostwerks.com/images/SeaCruiserCollage.jpg - 6063-T6

: The key will be finding an insert size that will allow a "sliding"
: fit,
: .2mm - .6mm, in the 20mm OD X 1.6mm wall tubing.

: Tom

Hi Tom,

While I've never tried using them as a removable slider, back in my ultralighting days sleeves were made useing the orriginal size tube then slitting them on a table saw then in a padded vice closing up the slit. Made a useable sleeve, that fit fairly snug.

Bill H.