How to Tie a Knot With Polypropylene Rope
Which rope should I use?
Rope to Practice Knot Tying
Almost any rope that is available in a marine or hardware store or online can be used to practice tying knots. After all, to use that piece of rope, it will have to be attached either to itself, to an object, or to another rope. And, that will require a knot!
Not all rope is pleasant to handle, some is too stiff or too slippery, and some is just too ludicrously expensive. No one rope is suitable for every knot, e.g., a three strand Eye Splice requires three strand twisted rope, a Brummel Splice requires hollow braid and, a Beer Knot requires tubular webbing. But, these are the exceptions. The following comments are aimed at the novice, parent, teacher, or scout leader who suddenly needs to buy rope just to practice, or teach, the more common knots.
THE RIGHT SIZE AND ROPE
Any size can be used but rope in the range 1/4 to 1/2 inch (6 mm to 12 mm) is suitable and allows each knot to be easily examined and also untied to allow the rope to be used again. Look for rope that is flexible and not too shiny or slippery. Strength is irrelevant.
ROPE TO AVOID
Avoid polypropylene rope – commonly blue or yellow – sold for water-ski towlines. It is not pleasant to handle and knots don't hold well. It may be cheap, float, and keep clear of propellors – but none of that will help you to teach a Bowline. Avoid the expensive, high-tech ropes sold for their exceptional strength and avoid the big spools of 1/8 inch (3mm) twisted three-strand nylon. Thin braided line is better, but 1/8 inch is still too small to be ideal.
NATURAL FIBERS
Natural fibers hold knots well and three-stranded versions are suitable for splicing. Tarred hemp and manila are both good for teaching. When used for splicing they hold their form and allow a neat final splice. However, they may not be readily available – especially in the size you want. Also, you cannot just "burn the end" to prevent fraying; you have to whip the ends or, at the very least, secure them with tape or a Constrictor Knot.
SYNTHETIC FIBERS
Nylon rope is often the easiest to find. Although heat can seal the cut end, be very careful: Nylon melts at well over 200oC and any contact will rapidly cause a burn. Nylon rope can be used to practice all the common knots and the three-strand version can also be used for a Back Splice, Short Spliceand an Eye Splice. When splicing, the principle disadvantage is that the fibers in each strand tend to become disorganized and make the final splice appear untidy.
For knot tying, Polyester (Dacron®, Terylene®, Trevira®) and Polyethylene are fine. By contrast, rope sold for use as a clothes line may have a plastic coating and will be be too inflexible. Braided rope sold in marine stores usually has an inner core and an outer sheath. While it is entirely suitable for practicing it is also needlessly expensive.
ROPE USED FOR OUR ANIMATIONS
We used different ropes for different properties – always with photography in mind. The brightly colored rope with no contrasting flecks wasVectran Double Braid by New England Ropes (Teufelberger); when delivered it was astonishingly rigid and tended to remain so until a little of the core was pulled out to relax the sheath. It may look great but, because of its rigidity, would would not be a great choice for teaching.
Brightly colored three strand nylon used to be hard to find. However, Knot and Rope Supply sells Bright Red and Bright Blue three-strand nylon rope as well as Double Braided nylon with additional colors: Bright Green and Bottle Green.
A decorative three strand cotton rope was used for some of the fishing knots, e.g., the Bimini Twist, because it permitted twisting – not as well as fishing line – but well enough to demonstrate the technique. Most of the rest of the photographs employed either yachting double braid or parachute cord.
How to Tie a Knot With Polypropylene Rope
Source: https://www.animatedknots.com/which-rope