Lazy Jacks 2
Lazyjacks -- Home made for about $25 and no holes in the mast or boom
by Ron Hill, Apache #788
I used 1/4 inch braided nylon line which goes from the aft portion of the boom over the top of the starboard spreader around the front of the mast and over the top of the port spreader back to the aft portion of the boom. I was afraid that smaller diameter line would get caught in the crack between the spreader and mast. In that area I doubled the line and added leather chafe guard in the area where it crosses the aft portion of the spreader. I used a monkey fist to throw the line over the starboard spreader, then went to the bow and threw it back over the port spreader.
I used some plastic clips that are clipped on to the cable portion of the boom's outhaul to secure that line (when the lazy jacks were completely finished). This line is not tight but hangs in a loose curve. I split the boom into quarters by sewing three vertical strands of line onto each side of the line I threw over the spreaders. These lines are not the same length. The longest is toward the mast and the shortest is aft. I covered the sewing joint with liquid rope whip and let the line hang down to about a foot above the boom.
I then sewed a loop on each side of these three pairs of lines using heat shrink as chafe guard. I secured a length of shock cord through the line loop on one side by sewing it together. On the other end of the shock cord I sewed a bronze swivel eye snap (these sewing joints are also chafe guarded with heat shrink). The swivel eye snap connects to the line loop on the opposite side of the boom. As a result, the shock cord hangs loosely under the boom. This was done with the mainsail and the mainsail cover on to get the correct dimensions.
I've had these on for at least 9 years and there have been no chafe problems with either the mainsail or the mainsail cover. They can be easily unsnapped and wrapped around the mast when I put up our large sun cover (mast to back stay), full boat winter cover, or as Gary Wiseman has pointed out, wrapped around the mast to counter mast pumping. Several other people in Fleet 12 have copied this idea.