Since the first powered lawn trimmers came onto the market, manicuring your lawn has become easier and faster. Today, most lawn trimmers use a cutting string that is wound onto a spool. As the trimmer cuts, the string will wear out and break off. New string can be fed from the spool, usually by tapping the trimmer head on the ground. Eventually, though, the string will be used up and need replacing. Changing the string in your lawn trimmer is a relatively easy procedure.
Removing the Spool and Preparing the String
Turn off or unplug the lawn trimmer.
Remove the spool retainer that holds the spool in place on the underside of the cutting head and set it aside. You should be able to smoothly unscrew the retainer, but the way the retainer attaches to the lawn trimmer may vary with the model of the machine. If you have problems removing the retainer, refer to the owner's manual.
Remove the spool from the spool head. You will notice a spring on the spool. Keep the spring in place on the spool.
Remove any old string from the spool.
Cut a length of new trimmer string 9 feet long. If the trimmer requires two strings, cut another of equal length.
Loading the Spool with String
Hold the spool with the spring facing up and insert one end of the string into the little anchor hole in the side of the spool. If the trimmer uses two strings, install the string in the upper area first.
Check the spool for an arrow that indicates the direction to wind the string. Wind the string around the spool by hand until approximately 6 inches remain.
Press the string into one of the string retention slots, if your spool has them, in the spool flange. Use the upper flange if your trimmer needs two strings.
If the trimmer takes two strings, insert the second string into the anchor hole in the lower area of the spool. Wind this string around the lower area of the spool until approximately 6 inches remain and press the string into the other string retention slot in the upper spool flange.
Replacing the Spool
Insert the end of each string through a guide hole in the cutting head and pull it through until about 5 inches of string extend from the hole.
Position the spring over the cutting head shaft and press the spool down onto the shaft.
When the spool is properly positioned, pull the strings sharply to release them from the retention slots.
Rotate the spool until it no longer turns.
Replace the spool retainer, turning the retainer in the opposite direction of the one you used to remove it. See your owner's manual for more details on how to replace the retainer for your particular model of lawn trimmer.
Pull the strings once more to align the spool into cutting position. Pull the strings while pushing the spool down to advance the string manually, if necessary.
About this Author
Located in Jacksonville, Fla, Frank Whittemore has been a writer and content strategist for over 15 years, providing corporate communications services to Fortune 500 companies. Whittemore writes on topics that stem from his fascination with nature, the environment, science, medicine and technology.