by GreenLake » Thu Jan 07, 2010 7:20 pm
There are two styles of reefing. Originally, the boom was set up to allow the sail to be rolled around it. The block for the mainsheet can be slid off easily (original fitting) and the gooseneck can turn if the push the boom forward. To complete the reefing, you need to use a claw as the attachement point for the mainsheet block. That claw needs another line to hold it in the fore-and-aft position. (Search this site for "reefing claw" to find older discussions). In principle, this method of reefing allows for continuous adjustment. I've never tried this (for lack of a claw, but also because I read that sail shape is terrible). I would assume the the reef claw also stresses the sail, as by necessity it has to rest on the sail fabric.
The second style uses pairs of grommets, one of each pair at the luff, and one at the leach. The one at the front of the sail is hooked into a reef hook, but it can also be lashed to the boom and/or mast. The former is faster, but all that's required is to secure it low and forward on the boom.
The second grommet needs to also be secured close to the boom, but pulled aft, so the sail tightens. That's where the cheekblock comes in. It's positioned to give the right angle of pull when the reefline that runs through it is pulled tight. To give extra purchase, insted of fixing the reefline in the grommet, you can fix it on the boom, opposite of the checkblock. That gives a 2:1 purchase and the pull is symmetrical.
On a small boat, there's no need for reef ties to tie the unused portion of the sail. I find that in the back the reefline will secure the folds of the sail. I'm currently using a reefline in the front as well, so I can secure the sail there, too. With a little tugging and pushing, the rest of the material lays stacked more or less flat against the boom and so far, hasn't ever blown out. Because you reef in strong winds, you want a flat sail, and therefore tension along the foot. That helps keep the reefed portion of the sail straight, and explains why there's apparently no need to adjust the angle of pull.
~ green ~ lake ~ ~