If you are building a kit from plans now the hunt is over for your aluminum mast.  The 6061-T6 grade aluminum tubing measures 1-1/2" O.D. with a 1/8" wall-thickness.  It's used in several of our sailing kits including the very popular Passagemaker Dinghy Sloop rig, Skerry Sloop and CLC SailRig kits.

We are selling the tubing in four, and eight foot lengths, as well as cut to length past packages with couplers for Passagemaker dinghy and CLC Sailing Rigs (40 sqft & 55 sqft).  Note that the coupler tube will slide snugly into the 1-1/2" O.D. aluminum tube lengths to give you the desired overall length of your mast.

Aluminum sections shipped shorter than 8' can avoid shipping surcharges and ship inexpensively, but if you desire tubing longer than 7-1/2', a shipping quote is required.