A small sail attaches to its ropes through reinforced rings at the corners (the primary points), through reef points sewn across it at roughly one third of its height, and through small loops or grommets along the luff for lashing to the mast. In the 5.6 square meter example, eight reef points share at most about 48 N each at force 5, while the corner rings, and the end rings of a reef, must be tested to many times that, because the corners carry the concentrated load.
Part of Small Sailboat Construction
Grommets, cringles and reef points are the reinforced holes and short lines through which a sail’s cloth is connected to its spars and ropes.
Three Families Of Attachment Point
Corner grommets. Metal or hand-sewn rings at the head, tack and clew, and at the peak of a sprit or yard rig. The sheet, halyard and downhaul pull on these, so they are the highest-stress places in the sail. A ring sewn through a stack of patches (see Cutting & Sewing) spreads the load into the cloth; a bare metal grommet punched into single cloth cuts through it.
Reef points. Short lines passed through the sail in a row and left hanging on each side. When wind rises you lower the sail to that row and tie the surplus cloth up, which the carrier gives as a reduction of about 30%. The reef row crosses the sail at about one third of its height.
Lashing points. Small grommets or loops along the luff, through which cord ties the sail to the mast (or to the spar), so the cloth slides on the mast rather than flapping away from it.
What You Need
- Rings: salvaged metal grommets with washers, brass or steel rings, or rope rings you make yourself
- A punch or a sharp awl, and a mallet
- Reef lines about 30-40 cm long, in rope that ties and holds
- Strong thread and the stitching skills in Hand Sewing Stitches
Method: Fit The Points
Step 1: Mark all points on the finished, patched sail before you punch any hole. Check them against the mast, the yard and the sheet leads.
Step 2: Set metal grommets through at least three patch layers, with the washer on the far side. For a hand-sewn ring, sew buttonhole stitches closely around a metal or rope ring so every stitch bears on the cloth.
Step 3: Sew each reef point through the sail with a through-stitch and reinforcing patch, so the line is held by two rows of stitching, not one.
Step 4: Fit end cringles at both ends of the reef row, as strongly as the corner rings, because they take the foot tension of the reefed sail.
Step 5: Lash and test. Lash the luff to a pole and pull the head with a rope loaded to the hang-test figure.
Worked Example: Load On A Reef Point
If the reef row crossing a 3.0 m wide sail has points every 0.4 m (a choice), there are 3.0 ÷ 0.4 = 7.5, so eight points. At force 5 the whole sail force on the 5.6 m² sail is about 382 N. The reef row carries at most part of this load, so an upper bound for the load on each point is 382 ÷ 8 = 48 N, as long as the load is shared evenly. A hand-sewn reef point with two stitch rows holds this easily. The end cringles, with no neighbour on one side, take the tension of the whole reefed foot: they need the corner-strength treatment (950 N per 5 cm strip in the hang test in Cutting & Sewing).
Common Mistakes
- Making reef points as light as sewing thread — they are small, but one that parts in a gust frees a flogging bunt.
- Punching a metal grommet through one layer — it cuts out under load.
- Knotting reef points too tightly to untie — use a flat knot you can release with cold, wet hands.
- Placing the reef too high — the carrier’s about 30% reduction relies on a row at roughly one third of the height.
Safety
Loose cloth and loose ends
A reef point left untied flaps and can catch a hand or a spar. Tie all points before you hoist, and keep fingers clear of the clew ring when the sheet is loaded.
What’s Next
- Learn next: Basic Sailing Skills — using the finished sail
- Combine with: Lug Sail Rig — reefing a lug sail