Using a mitre box for tall skirting involves carefully positioning the board to ensure the saw guides provide accurate angle cuts, even if the board extends above the box. A mitre box is designed to simplify precise angled cuts by providing pre-set guides, typically at 90° and 45°, removing the need to draw guide lines directly onto your material. You simply place the skirting board inside the box and use your hand saw to make the cut.
Understanding Your Mitre Box
A mitre box is a fundamental tool for achieving accurate angled cuts, especially for trim work like skirting boards. Its primary function is to hold your material steady while guiding a hand saw (such as a tenon saw or panel saw) at specific, precise angles.
- Pre-set Guides: Most mitre boxes feature slots cut into their sides at common angles like 90° (straight cut) and 45° (for internal and external corners). Some models may offer additional angles.
- Material Support: The base of the mitre box provides a flat surface to rest your skirting, while the side walls help keep it stable during the cut.
For tall skirting, the main consideration is that the board's height might exceed the depth of the mitre box guides. However, the critical aspect is that the angle is still determined by the slots at the base of the box. Your saw will follow these initial guides, and you must maintain that angle as the blade continues through the taller portion of the skirting.
Preparing for the Cut
Proper preparation is key to accurate and clean cuts, especially when dealing with taller materials that require more careful handling.
Essential Tools
Before you begin, gather the following:
- Mitre Box: A sturdy wooden or plastic mitre box.
- Hand Saw: A panel saw or tenon saw with a fine tooth count and a deep blade. A deeper blade is crucial for cutting through tall skirting effectively.
- Tape Measure and Pencil: For accurate measurements and marking.
- Clamps: Essential for securing the skirting board firmly within the mitre box, preventing movement during the cut.
- Safety Glasses: Always protect your eyes when cutting.
- Work Surface: A stable workbench or surface at a comfortable height.
Measuring and Marking
Accurate measurement is the first step to a perfect fit.
- Measure the Wall: Carefully measure the length of the wall section where the skirting will be installed.
- Determine the Angle:
- For internal corners, you'll typically need a 45° angle cut on the face of the skirting, angled inwards (a "return" cut).
- For external corners, you'll need a 45° angle cut on the face of the skirting, angled outwards.
- For straight joins or end pieces, a 90° cut is often used.
- Mark the Skirting: Transfer your measurements to the skirting board. Use a pencil to mark the precise point where the longest edge of your angle cut will begin or end. Remember the adage: "measure twice, cut once."
- Tip: When marking, consider whether you're cutting for an internal or external corner, as this dictates which side of your mark the saw cut should fall to ensure the correct length after the angle is created.
Step-by-Step Guide to Cutting Tall Skirting
Successfully cutting tall skirting with a mitre box requires focus on stability and maintaining the cutting angle throughout the board's height.
Positioning the Skirting
- Place the Skirting: Lay the skirting board flat against the back fence of the mitre box. Ensure the decorative edge (the visible edge once installed) is facing upwards, or as it would be oriented on the wall. The piece you intend to keep should be firmly pressed against the back of the mitre box.
- Align the Mark: Line up your pencil mark on the skirting with the desired angle guide slot in the mitre box. For example, if you need a 45° internal corner, position the mark at the start of the 45° slot.
- Secure with Clamps: This step is critical for tall skirting. Use one or more clamps to firmly secure the skirting board against the back fence and down onto the base of the mitre box. This prevents any movement, which is particularly important as the saw will cut above the main guiding slots for a portion of the board. For very tall boards, you might consider temporarily attaching a support block to your workbench to support the outer section of the skirting, preventing it from drooping.
Making the Cut
- Insert the Saw: Place your hand saw into the chosen guide slots. Ensure the saw blade is flush against the sides of the slots.
- Start the Cut: Begin sawing with light, even pressure, using long, smooth strokes. Let the saw's weight do most of the work.
- Maintain the Angle: As the saw blade progresses through the skirting, especially when it extends above the mitre box's guiding slots, it's crucial to consciously maintain the vertical angle. The mitre box guides the initial part of the cut, but you must guide the saw blade through the upper portion of the material freehand, keeping it perfectly aligned with the cut started by the box.
- Complete the Cut: Continue sawing until the cut is complete. Apply slightly less pressure as you near the end of the cut to prevent splintering on the underside of the skirting.
Ensuring Accuracy
- Test Cuts: If you're new to cutting tall skirting, practice on a scrap piece first. This helps you get a feel for maintaining the saw's angle.
- Sharp Blade: A sharp saw blade makes clean cuts and reduces the effort required, minimizing the chance of deviation.
- Check Fit: Always dry-fit your cut pieces of skirting before final installation. Minor adjustments can often be made with sandpaper or a block plane.
Tips for Success with Tall Skirting
- Deep-Bladed Saw: Prioritize a hand saw with a deep blade. This allows the blade to pass through the entire height of the tall skirting without the saw's spine hitting the top edge of the board.
- External Support: For very long pieces of skirting, especially when cutting at an angle, ensure the unsupported end is propped up to the same height as the mitre box base. This prevents the skirting from sagging, which can lead to inaccurate cuts.
- Clean Sawing Motion: Use a consistent, smooth sawing action. Avoid jerky movements or trying to force the saw, which can cause the blade to wander, especially in the unsupported upper section of tall skirting.
- Score the Line (Optional): For extreme accuracy on very tall boards, after the initial cut guided by the mitre box, you can slightly extend the line of the cut upwards on the face of the skirting before continuing to saw. This provides a visual guide for the upper portion of your blade.
Common Challenges and Solutions
| Challenge | Description | Solution |
|---|---|---|
| Inaccurate Angles | The cut isn't perfectly 45° or 90°, leading to gaps at corners. | Ensure the skirting is firmly clamped and pressed against the back fence. Start the cut slowly, letting the mitre box guides dictate the initial angle. Maintain a steady, vertical saw stroke. |
| Splintering | The cut edge is rough or splintered, especially on the top face or exit side. | Use a sharp, fine-toothed saw. Apply painter's tape along the cut line on the decorative face before cutting to minimize splintering. Cut with consistent, light pressure as you finish the cut. |
| Wobbly Cuts | The saw blade deviates from a straight line, resulting in an uneven cut surface. | Firmly clamp the skirting. Keep a tight grip on the saw handle, guiding it smoothly. Avoid applying excessive downward pressure, which can cause the blade to buckle. |
| Skirting Movement | The board shifts during cutting, causing misalignment. | Always use at least one, preferably two, clamps to secure the skirting to the mitre box base and back fence. Consider anti-slip matting under the mitre box itself. |
| Saw Blade Not Reaching | The saw's depth isn't enough to cut through the entire height of a very tall skirting board in one pass. | Ensure you are using a hand saw with a sufficiently deep blade (e.g., a panel saw). If still an issue, carefully flip the board and make a second cut, ensuring perfect alignment with the first. |
By following these steps and tips, you can effectively use a mitre box to achieve precise angled cuts on tall skirting boards, contributing to a professional finish in your home. For more detailed visual guidance on specific cuts, explore resources from reputable DIY sites like This Old House or Family Handyman.
