I'm not sure that I 100% understand you here but it seems to me that the most simple solution to your problem would be to...
-- remove the furling line by untying it from the knob on the mast.
-- Spin the mast until the sail is tightly coiled around it.
-- Re-tie the line to the knob on the mast.
-- Now every time you pull the mast out to use, the furling line will have naturally been coiled around the mast to the correct length. Cleat it when you reach the sail size you want. Once the line is cleated, the sail can't pull outward any more as the mast can't pull in any more of the slack.
If you want to make 100% sure it gets furled in completely (as sometimes the slack in not 'tightly' winding the sail results in a foot or so left out when you pull it back in) then manually add an extra loop or two after re-tying the line to the mast. Personally, I find this foot of extra sail negligible so I'm OK with it.
Also, I 'personally' find the line actually ends up working best if in the second step, I wrap the sail with a clockwise twisting motion. That way, as I eventually pull in the sail by pulling the line through the loop on the right bar of the a-frame, (right next to the cleat,) the angle the line has to pull through the loop is not as sharp.)
Again, I wasn't 100% sure what you meant but I hope this helps.
Last edited by Murph_PEI on Thu Jun 14, 2012 11:38 am, edited 3 times in total.