1. Big belly in the reefing band (see panoramic photo below).
2. Tendency for the sail to be sucked down into the slot in the boom, very bad if this happens. (Photo 4)
3. To see if moving the dead-end aft made a difference I used a snatch block on the end of the boom (Photos 5 and 6). This pulled the reef band much flatter, but as it turns out if I pull the cringle aft, the slot and pulley are a good 50mm forward of the "clew" of the first reef.
4. I realized that I needed to move the attachment point much farther aft and the cheek block at least 1" aft of the straight line distance from the luff to the leech at the reefing band.
5. Later I found out this was an oversight when our new sails were made.. When we moved from the original three reef points to two "deep and deeper" reefing points (almost a 1.25 and a 2.5 reef) this caused the reefing cringles to move forward; this made it impossible to put in a decent flat reef. I was inexperienced enough to not notice this problem at first.

1. Reefing line was on a padeye with a ring hitch port side of boom.
2. Reefing line ran through the cringle and back down to a slot in the boom.
3. Slot and padeye were at the same distance from gooseneck.
4. There was a cheek block inside the boom which led the reef line to an exit near the boom-mounted winch.
5. Chafing was a problem due to misplaced cheek blocks and exit blocks.

The method for reefing is to release the main halyard line clutch, lower the mainsail to the reef point, engage the clutch, and clip on the reefing shackle. Leave the halyard loose, take up on the appropriate reef line with the line clutches closed. The lazy reef line needs to be brought in by hand as the working line is tightened. We have placed a whipping around the line at exactly the right point so when it exits the line clutch, the outer reef line is at the correct tension. Finally, take up the halyard to remove the slack. Don't put too much force on it.

Type: double-braid or high-tech?

Strength: at 5:1 breaking-load-to-working-load ratio the following figures imply around 16,000 pound breaking load.

With the above load figures this implies a 7/16" or 1/2" high-mod line such as Validator II or Warpspeed

I chose to use 3/8" (10mm) Validator II with a BL of 11,000 pounds. This has a 100% vectran core with polyester cover.

Starzinger and Evans say that reef lines should be moderate stretch (3 out of 5) and low weight (4 out of 5) 

"Reef lines tend to be shorter and lower than the halyards so are a little less sensitive to stretch and weight, but is prone to chafe from the many sharp turns and experiences a lot of flogging. They typically use line at one notch down in sophistication/cost from that used for the halyards"

As I think about the line loading problem I am wondering about the load calculations.  I calculated Main Sheet Loadings (below) when choosing winches based on the formula on the Harken website. Carol Hasse of Port Townsend Sails supplied different numbers.

Another approach is to ask "how many pounds can I apply to a line with my winches"?.   Based on my arm strength and winch sizes (40 on the halyard winch) the most I can reasonably crank into a line with a 10" handle is 30 pounds * 10" / 12" *  power factor.  This works out to be 25X the Winch Power Factor.   For the 40 winch that is 1000 pounds.  On the mainsheet I have a 5:1 advantage but on the reefing line I only have a 2:1 advantage with lots of friction.  So although Hasse has calculated a maximum load with gusts of around 3400 pounds, all I can crank in with the winch is 1600 pounds.  The load on the mainsheet might be 3400 pounds, but it's unlikely that the load on the reefing line will be so great except in very strong gusts.  It's true that without the sail slugs the load has to be divided between the luff and the reef cringle.  It might have been prudent to upsize to 7/16" Validator II (with a BL of 15,200); but if we are sailing in wind gusts over 50 knots it is probably time to put up the trysail.

Maybe there is some practical experience here that dictates reef line size and quality.  At this time my biggest problem seems to be chafe and I think a lot of that comes from the misplaced dead-end and cheek block positions. So far, with the new reefing system, chafe has not been a problem.