Step 1: Using a router, rout a groove 12mm wide from one edge on each piece of clear pine and as deep as the thickness of the mirror you are going to use. 4mm was used for the pictured project. Remember to use appropriate safety gear for this task (safety glasses, ear muffs or plugs and a disposable dust mask).
Step 2: Draw a 45 degree line using a set square or combination square at one end of each piece of timber. If you have a mitre box place timber in box. Cut to the line using a Tenon saw.
Step 3: When cut through, clean up the ends with sandpaper being careful not to change the shape of the joint on the sides.
Step 4: Using a measuring tape hook one end on the base of the angled cut and measure to a point at the length you require for your mirror. In this project the Mirror frame was cut at 800mm.
Step 5: Carefully draw another 45 degree angle from the mark with the slope of the set square running back towards the end which the tape measure is on. Double check that the points of the angles are on the same edge of the timber and pointing away from each other.
Step 6: Using the mitre box again, repeat step 3.
Step 7: Repeat the above steps for the Mirror Rails (shorter sides). In this project the sides are 500mm long.
Step 8: Place angles of a long side and a short so they meet. Have the rebated sides facing downwards. Check for squareness using the set square. If there is a gap along the joint use a small hand plane and make a couple of fine cuts and retry joint.
Step 9: Place tie down strap around entire frame and check all angle as in step 8.
Step 10: Once you are satisfied with your work, release the strap and place a generous amount of Selleys Aquadhere Interior on the angles of the 2 shorter sides. Place all pieces into position and apply the tie down strap and tighten. Wipe off excess glue squeeze out with a damp rag. Allow to sit for 30 minutes.
Step 11: Measure the distance from the inside wall of the rebate to the inside wall rebate on the opposite side i.e. rail to rail (short bits) and style to style (longer bits). Subtract 1mm of each measurement. This will give you the size of your mirror so you can purchase or order.
Step 12: Use a cork sanding block and go over the entire frame feathering in the joints and rough bits.
Step 13: Soften the harshness of the inside of the frame by lightly sanding the edges with some fine grit paper (180 or 240 is fine).
Step 14: After you’ve picked up the mirror do a dry test fit. There should be about a ½ mm gap around the Mirror to the frame. Remove the mirror. Using a caulking gun, apply a thin bead to of Selleys All Clear around the entire frame keeping the bead mostly in the area of where the wall and floor of the rebate form an angle.
Step 15: Reposition the mirror into the frame and press down gently with your hand on the Mirror back to settle it into place. If required clean off any sealant squeezed out from the back.
Step 16: Place a bead of Selleys Aquadhere Interior all around the back of the frame about 30mm from the mirror edge place a pre-cut piece of 3mm MDF or thin ply over the back. Have it about 40mm smaller than the overall size of the frame. For added security staple pins into place using a staple gun.
Step 17: Insert 2 x 8x30mm screws about ¼ of the length from the top using a screw driver.
Step 18: Connect some framing wire or strong cord to the screws and you’re ready to hang your mirror.