Hi all,
Tom wrote few days ago he built boats using 3/4" (6061-T6) X .037 wall tubing Vs .049 and that he is still happy with them.

So today I found these tubes for sale: 5/7" (18mm outer - 16mm inner) x .039 (1mm)
and inserts .607 (15.4mm outer - 14mm inner) x 0.028 (0.7mm)

There are also available inserts 5/8" (16mm outer -14mm inner) x .039 (1mm) but they will fit looser i think.

Would you go for inserts .028 better fitting or .039 loose fitting?