String-type lawn trimmers are such labor-saving tools that most homeowners and lawn-care experts consider them indispensable. Whether your string trimmer is powered by electric cord, rechargeable batteries or gasoline engine, restringing new line onto the trimmer spool is one of the most frequently performed maintenance tasks.
Some string trimmers use a pre-cut string piece. For this type, you simply remove the used piece of string, and snap in or screw in a new one. Other string trimmers have a spool of cutting line that you must wind with new line when it is empty. To dispense more line, some of these require you to turn off the trimmer and pull out more cutting line. Most trimmers have a "tap-and-go" type of spool that automatically releases more line while the trimmer is running. Whichever way the line is dispensed, the spool is loaded by a similar method.
Remove the spool from the bottom of the trimmer. On most models, you must remove a cap, then push a button or release mechanism and lift off the spool.
Clean out any grass and debris from under the trimmer and from the spool mount. Remove any pieces of cutting line that may be stuck in the housing or in the grooves on the spool.
Cut a piece of replacement line about 6 feet long. Double it, having the cut ends even on one end and leaving the "fold" on the other end.
Take the empty, cleaned spool, and hook the "fold" end of the new line into one of the slots in the spool shaft. The slots are found between the two main grooves.
Slowly turn the disk in one direction, and allow the cutting line to wind onto the spool on both sides. The line will wind on both sides in the same direction. Wind until there are about 6 inches of the cut ends of the line left free.
Insert one of the cut ends of the line into one of the feed slots on the upper part of the spool and insert the other cut end into the other feed slot, which is halfway around the spool.
Hold onto the cut ends so the line does not slip and unwind. Place the spool back onto the trimmer shaft, threading the line ends through the trimmer feed holes. On some models, you may need to begin threading the ends through before you place the spool onto the shaft and pull the ends through as you snap the spool into place on the trimmer.
Replace the cap.