Hi all,
Slab reefing is hard to beat for ease of use, simplicity, trouble free-ness in executing, and quality of the end result. Running the outhaul reef lines through the end of the boom, up and through the reef cringle and back to the boom for securing is both a common and preferred way to run your mainsail’s reef outhaul. One challenge is that the positioning of the reef line around the boom has to be just so to pull the clew of the reef to the boom and give the reef good sail shape. And then, once positioned, to not move fore or aft when the reef line is loose in normal sailing, but stay in place.
Many put a pad eye at the appropriate spot and run the reef line through the eye. This does not have to be strongly mounted as it is merely for positioning: the boom carries the load.
But then there comes a time when the positioning is not quite right: the sail has stretched a bit, say, or definitely when you get a new sail. Even a sail with the same design will be subtly different and the pad eyes will no longer be located properly.
A solution I have used for decades on a couple of boats is to install a pin track (small boat jib sheet adjustment track) with cars with an eye big enough for the reef line. The track cars with bales will merely be for positioning (not strength), so not every bolt hole need not be used for installation.
In this way, small adjustments can always be made when needed by moving the cars along the track by moving the capturing bale one way or the other. I suggest using a bit longer than expected track/cars: mine holds bales for 3 reefs and, unexpectedly, has become handy for positioning my aft lazy jack line. And when a new sail is purchased, there will be no need to reposition the pad eyes: even if the sail is a “duplicate” there will be adjustments needed.
My best, Dick Stevenson, s/v Alchemy