Basic Rope Work for Boat Owners - Eye Splices, Whipping and Sealing Line Ends

Buy a few feet of half-inch three-strand nylon or polyester and practice two or three splices before you work on a good line. Three-strand rope has a "lay" (the direction the strands twist). All the tucks go against the lay, and once you've done one it clicks.

If the end was hot-cut at the store, cut off the melted tip (tape first, then cut through the tape). Tape the end of each of the three strands tightly so they don't fray. Unlay (untwist) enough rope for your tucks. Animated Knots' rule of thumb is about three times the rope's diameter per tuck. Put a wrap of tape around the rope where the unlaid part meets the rest, so it stops unraveling there.

Bend the end back to make a loop of the size you want. The tape wrap marks where the eye closes. For an anchor line, wrap the eye snugly around the thimble now; a piece of tape on each leg holds it in place while you work. BoatUS's Mark Corke points out that thimbles are sized to the rope's diameter, and one that is the wrong size will work its way out of the eye, so buy the thimble for your exact line size. He also tapes the strand ends rather than melting them, because a melted end is hard and makes the tucks more difficult. Lay the three loose strands on top of the standing part (the long part of the rope), spread out: one in the middle, one to each side.

Lift one strand of the standing part, right where you want the eye to close, and push the middle loose strand under it, against the lay. BoatUS's memory aid: the first tuck is always the center strand. Soft rope opens with your fingers; stiff or large rope needs a fid or marlinspike to open the strand. Pull it through until the eye closes, but don't pull so hard you distort the rope.

Take the next loose strand and tuck it under the standing strand next to the one you just used, going the same direction. The third tuck is where most people go wrong: flip the eye over, and tuck the last loose strand under the one remaining standing strand, still going the same direction. Now each loose strand should come out from under a different standing strand, evenly spaced around the rope. Pull all three snug.

Take any loose strand, pass it over the next standing strand and under the one after that. Do the same with the next strand, one tuck at a time, rotating the rope a third of a turn after each tuck so you keep your place. Animated Knots suggests holding the two waiting strands one on each side so you always know which comes next, and twisting each strand slightly as you go to keep its shape. BoatUS recommends six full rounds of tucks; for mooring lines, tow lines and other critical uses, more is better. Follow the rope maker's instructions if they give a number.

Roll the splice under your foot on the floor to smooth it, then put a strain on the eye (loop it over a post and pull) to set the tucks. Trim the tails, leaving short stubs, and melt the stubs on synthetic rope so they don't pull out. Animated Knots notes the melted stubs are slightly fatter than the strand, which helps lock the splice. It also warns that old-style thinned, tapered tails tend to work loose in modern slippery rope, so occasional splicers are better off with full tucks.

Every cut end needs sealing:

• Melting. For nylon and polyester, a hot knife or a flame seals the end. Tape it first, cut through the tape, then melt just enough to fuse the fibers. Animated Knots recommends melting synthetic ends even when you also whip them.
• Common whipping. Wrap waxed twine tightly around the rope near the end, trap the end of the twine under the wraps, and pull it out of sight. It's quick and needs no needle, but Animated Knots notes that if one turn gets cut, the whole whipping can unravel fast.
• Sailmaker's whipping. The twine is passed between the strands and the outer "frapping" turns follow the grooves, so it holds even if damaged. Animated Knots calls it the most secure whipping; use it on lines that work hard.
• Back splice (three-strand only). A crown knot at the end, then each strand tucked back into the rope about three times. It needs no twine or tools, so it's handy when you have nothing else. Animated Knots treats it as a temporary fix to replace with a whipping, because it makes a bulky end that won't pass through blocks or fairleads.
• Cores that don't melt. For rope with a core that won't melt (such as an aramid core), Animated Knots suggests trimming the core a little shorter than the cover and melting the cover over it.

A double-braid eye splice works by pulling the core out, burying the cover inside the core and the core inside the cover, with exact measurements from the rope maker's instructions and a fid sized for the rope. It's very learnable, but it takes patience and the right tools, and a mistake can leave a splice weaker than you think. In BoatUS's step-by-step, Mark Corke ties a slipknot well up the line and hangs it on a winch or cleat so he can pull against it, cuts off any melted end so the core slides freely, and uses a fid that matches the core diameter. Good options:

• Learn it if you replace a lot of line, using the instruction sheet from the maker of your rope (methods differ between brands and constructions).
• Buy pre-spliced dock lines. BoatUS notes they cost more than line off the spool and come only in set lengths. Check the eye actually fits over your cleats before you cut the tags off.
• Have a rigger or marine store splice it to the exact length and eye size you want.

Practical Sailor found that worn spliced dock lines tended to break at the end of the splice away from the eye, where the tails enter the rope. Look and feel there and along the eye. Signs to retire or re-splice the line:

• Tucks pulling out, loose or uneven
• Chafe, flat spots or cut strands at the eye, especially where it rides on a cleat or chock
• Glossy, glazed, hard or stiff areas, which Samson says can mean heat, grit or shock loading
• A thimble that's loose, rusted, or crushed and cutting into the rope
• Fuzzy, broken outer fibers all along a line that's been in the sun for years

Samson suggests end-for-ending (swapping the ends) so wear moves to a different spot, and BoatUS notes that's one more reason to know how to splice: when an anchor line's working end gets worn from chocks and the bottom, you can turn it around and splice a new eye at the other end. Add chafe gear where lines cross edges, and rinse lines in fresh water now and then.