For a weak recurve (25lbs or less) it’s not necessary to reinforce the tips of the limbs. A few small files I use for jewelry worked well to carved the notches. Be sure to round over the edges of the groove so that the string won’t wear out with use.
For these lighter bows nylon twine will be more than strong enough to serve as a string. The twine itself is a bit too narrow for the nocks of arrows to grab and shoot accurately. This can be worked around by twisting the string in a special way (shown below) to double its thickness.
Before making the twisted string, determine how long it will need to be by stringing your bow with a bit of untwisted twine. Tie two bowlines on either end of the twine and string the bow.
A string that is too long or too short for the bow will greatly hinder its performance. The distance between the string and the riser is called the brace height. Although it will be slightly different for each bow a good ballpark range is around 7” for the brace height.
To make the twisted string that will actually go on the bow, cut a piece of twine that is three times the length of the twine just used to string the bow.
A video showing how to twist the string is below. In case its hard to see, here’s what is happening: Fold the string in half with a loop on one side. Pinch the end of the loop with one hand. With your index and thumb of the other hand, twist the top strand away from you. At the end of the twist grab the bottom strand between the top of your index finger and the pad of your middle finger. Rotate your hand back to the front while holding all the strands. Inch your hand that is pinching the loop toward the newly formed twist. Repeat. NOTE
in this video I am showing the twisting process with the hemp string as it is a lot easier to see in the video than the nylon. You want to twist the nylon twine for the bowstring NOT the hemp.
Now that you have a large piece of twisted nylon twine, tie a double knot in the end to stop it from unwinding and cut and melt the end. Tie a bowline on either side of the string at the appropriate spot on the string Follow each bowline up with a simple overhand knot and cut and melt the ends.
Almost done with the string! The section of the string where you grip and nock an arrow takes a lot of abuse while shooting. An additional thin layer of twine can be added to reinforce this area. This process is called serving the string. The serving should span a few inches blow the arrow shelf to a few inches above.
To stop the serving from coming undone and sliding up and down it will be necessary to thread the hemp twine through the bowstring. A small nail can be inserted into the twisted bowstring to aid in threading the hemp. The tape in the above photo serves to hold the hemp in place during the twisting.
This method is similar to a basic whipping. However, the hemp to weak to try and pull the end loop back into the coil. Instead, thread the working end of the hemp through the tiny exposed look and through the bowstring. Tie a clovehitch, trim the excess and apply a dab of superglue on the end to keep it from coming undone.