How to Replace Strimmer Line: A Step-by-Step Guide
To replace the line on your strimmer (also known as a weed whacker or grass trimmer), you must first ensure the tool is powered off and disconnected. The core process involves removing the spool head, cutting the correct length and diameter of replacement line, threading and winding it onto the spool in the direction indicated by arrows, feeding the ends through the eyelets, and reassembling the head. While the specific method varies slightly between bump-feed and manual wind spools, the fundamental steps are universal.
Understanding Your Strimmer Spool Type
Before you begin, identify which type of spool your strimmer uses. The two most common mechanisms are:
- Bump-Feed Head: This is the most common type on modern electric and petrol strimmers. It features a spring-loaded spool. When you tap (or “bump”) the head on the ground while it’s spinning, a mechanism releases a small amount of new line. The line is pre-wound onto an inner spool that sits inside the outer housing.
- Manual Wind Spool: Found on some older or simpler models, this type requires you to manually wind the line onto a fixed spool. There is no automatic feed mechanism; you typically need to stop the strimmer and wind more line by hand when it gets short.
You can usually tell which type you have by looking at the head. A bump-feed head will have a button or bump knob in the center. A manual wind spool often has a simpler design where the line is wound directly around a central hub.
Choosing the Right Replacement Line
Using the wrong line can lead to poor performance, frequent breakage, or even damage to your strimmer. Always check your owner’s manual for the manufacturer’s specifications.
Line Diameter
The diameter (thickness) of the line is critical. Common diameters range from 1.5mm to 3.0mm. Thicker line is more durable for thick weeds but requires a more powerful motor. Using a line that is too thick for your model can strain the motor and cause overheating.
Line Shape
Replacement line comes in various shapes:
- Round: The standard, all-purpose shape. Good for general grass trimming.
- Square or Star: These shapes have edges that cut more aggressively and are better for thicker, tougher weeds.
- Twisted or Helical: Designed to reduce noise and wind resistance.
Line Length
The amount of line you need depends on the size of your spool. A typical residential strimmer spool holds between 3 to 5 meters (10 to 15 feet) of line. Overloading the spool can cause jamming and poor feeding.
Step-by-Step: Replacing Line on a Bump-Feed Spool
This is the most common procedure. Follow these steps carefully:
- Safety First: Turn off the strimmer and disconnect it from the power source. For cordless models, remove the battery. For petrol models, ensure the engine is off and cool.
- Remove the Spool Head: Press the release buttons or tabs on the side of the trimmer head (often two or more) and pull the outer spool housing off the trimmer body. You may need to press a central button or unscrew a cap.
- Remove the Old Line: Take out any remaining old line from the inner spool. Clean out any grass or debris.
- Cut New Line: Cut a length of new line as recommended for your spool (typically 3–5 meters). Ensure you are using the correct diameter.
- Thread and Anchor the Line: Look for the anchor point on the inner spool—this is often a small hook, notch, or hole in the center. Thread the midpoint of your cut line through or around this anchor point so that you have two equal lengths extending from the spool.
- Wind the Line: Wind each half of the line tightly and neatly onto the spool in the direction indicated by arrows molded into the plastic. Keep tension on the line as you wind to prevent tangles. Wind the lines onto their respective channels without crossing them.
- Secure the Ends: Once wound, tuck the last few centimeters of each line end into the temporary holding notches on the edge of the spool. This keeps the line from unwinding during reassembly.
- Reassemble the Head: Place the wound inner spool back into the outer housing. Align the tabs or guides and push until it clicks securely into place. Ensure the line ends are feeding through the metal eyelets on the outer housing.
- Test the Feed: Pull on each line end to ensure it feeds smoothly. Start the strimmer and tap the head on the ground (while spinning) to test the bump-feed mechanism.
Step-by-Step: Replacing Line on a Manual Wind Spool
The process is similar but simpler, as there is no inner spool mechanism.
- Safety First: Power off and disconnect the strimmer completely.
- Access the Spool: You may need to remove a cap or cover to access the winding hub directly.
- Cut New Line: Cut the appropriate length and diameter of line.
- Anchor the Line: Find the anchor point (a hole or notch) on the spool hub. Thread the midpoint of the line through it.
- Wind the Line: Wind each half of the line neatly onto the hub in the direction indicated. Keep the coils tight and side-by-side.
- Secure and Reassemble: Once wound, feed the ends through the eyelets. Replace any covers or caps securely.
- Test: Start the strimmer and check that the line is feeding correctly. On a manual spool, you will need to stop and unwind more line by hand as it wears down.
Troubleshooting Common Strimmer Line Problems
Why does my new line keep breaking?
Common causes include using a line that is too thin or brittle, hitting hard objects like fences or walls, or allowing the line to become too long (which increases centrifugal force and stress). Ensure you are using the correct diameter and shape for your model and trimming technique.
Why won’t the line feed out from a bump-feed head?
This often happens if the line is wound too loosely, wound in the wrong direction, or tangled on the spool. It can also occur if the bump mechanism is clogged with debris. Remove the spool, check the winding direction (arrows), ensure the line is tight, and clean the head thoroughly.
How do I fix tangled or jammed line on the spool?
Remove the spool head and carefully unwind the tangled line. Clean out any grass or dirt. Rewind the line neatly, following the direction arrows, and ensure there are no crossovers between the two line channels. Apply slight tension while winding.
Frequently Asked Questions
Can I use any brand of replacement line for my strimmer?
Yes, as long as the line matches the specifications (diameter and shape) recommended by your strimmer’s manufacturer. The brand is less important than the correct size and type.
How often should I replace the strimmer line?
You don’t replace the line on a fixed schedule. You replace it when it breaks or wears down to a length that is ineffective for trimming. Carrying a pre-cut length of spare line in your pocket while working is a common practice.
What is the difference between bump-feed and auto-feed strimmers?
The terms are often used interchangeably. “Auto-feed” or “bump-feed” both refer to the mechanism where tapping the head releases more line. A “manual wind” spool requires you to stop and wind more line by hand.
Is it normal for the strimmer to vibrate more after changing the line?
Slight vibration can occur if the two lengths of line extending from the head are not equal. Ensure both ends are the same length after installation. Excessive vibration may indicate the spool is not seated correctly or is unbalanced.
