Wednesday 11 July 2018
Two pieces of skirting joint, one internal corner… how do you cut that mitre quickly?
First, butt one piece of board right up to the corner where the walls meet. This piece will stay here permanently, so if the other end of it is properly jointed, it can be fixed. Then present the other overlength board to the fixed piece and use a scribing block to mark up the side of this board, giving the first boards orientation vertically
Using the width of a ruler, transfer the first line away from the cut edge of the skirting board (follow any curve in the fixed board, too), leaving enough room for you to cut a 45 degree mitre to the edge
From where your line intersects the top of the skirting board, mark a 45 degree mitre away from this point. The direction of the mitre should be as if you are cutting a true mitred joint for the internal corner
Next, using your handsaw, cut down the line of the 45 degree mitre, being sure to follow the line along the front edge of the skirting board
Mark a pencil line along the obtuse angle of the mitre where it meets the front of the timber, along the straightedge and along the top moulding. Cut along the line down the front face of the board at about 90 degrees to the front face, undercutting slightly. It is important to stop cutting as soon as the kerf meets the moulding. Then simply chisel away this offcut with a chisel
Next, take a coping saw, and carefully cut along the line you drew on the moulding, where the mitre cut meets the moulding – again, undercutting slightly towards the back of the skirting board
The scribed shape you have formed on the moulding and along the front face of the skirting board means it should now butt up perfectly to the first piece of skirting fitted. You may find if your coping saw cut wasn’t perfect you will need to adjust the edge, but this method produces a perfect looking joint. The mitred scribing cut follows the moulding perfectly, producing a nice joint with no gaps, even down the skirting board face. Job done
Getting the mitres right on skirting boards can be a difficult process. Walls are rarely truly plumb, and don't often meet each other at exactly 90 degrees. So, here are a few tips I picked up during my days as a carpenter and joiner. There are two main joints… the internal and external mitre… and I'll tackle the external mitre next issue. For this issue, I'll look at scribing the internal mitre, which elimates any worries about the angle of the walls. I will not look into fixing the boards to the wall, as the method will depend upon the walls, and your preferred option.