How to install a letterbox
To make building your table even easier, have your timber pre-cut at your local Bunnings. Our cut list for this project is as follows.
Table frame (rebate depth)
Treated pine tabletop supports
Clamp your first piece of timber for the frame to the workbench. Set the guide on the circular saw to the depth you want. Our rebates were 35mm wide and 19mm deep. Cut 1 rebate, then turn the timber over to cut the other. Repeat this step for all 4 pieces of the frame.
Take 1 of the longer pieces of timber for the frame and use the mitre saw to cut it at a 45-degree angle. Repeat this for the other pieces of timber in the frame.
Measure and mark from the longest point on the mitre cut to the length you want the frame to be. Use the circular saw to cut the other ends of the frame to 45-degrees. Sand the edges to make them smooth.
Because the table will be sitting outside in the rain, use a 5mm drill bit to drill 6 drainage holes in the rebate of each of the long sides of the frame and three along the shorter ends.
Clamp the 4 sides of the outer frame to the workbench so that their edges are flush. Use a 3mm drill bit to drill a hole right through the corners of the frame. Then re-drill the hole, using a 6mm bit as a countersink to hide the screws.
Apply glue to each joint, but not too much, you don't want it to stain the timber. Join the frame together, then reinforce using use the drill and 65mm screws.
Flip the frame over and staple where the rebate joints meet. We used 0.5 inch staples. Also use staples to join the 45-degree mitre joints underneath the frame making sure they won't be visible.
Measure the positioning of the planks, then use the 5mm drill bit to pre-drill the holes that will secure them. Pre-drilling ensures the screws will be easier to insert and will help identify where they need to go.
Place the merbau decking into the frame. Use a 3mm packer between each plank to make sure they're evenly spaced.
Use three 40mm screws to secure each plank of the decking from underneath. Once each piece of decking is secure, turn the tabletop over and insert the rest of the screws.
Measure and mark where the five brace supports will go underneath the tabletop. Remember to leave enough space for your drinks cooler. Ours will be positioned at one end of the table, but place yours wherever you like.
Use the 3mm drill bit to pre-drill at least three holes, at the ends and in the middle of the five supports. Then use 40mm screws to attach the brace supports under the table. These will stop the timber from cupping in the winter.
Measure and mark the support frame for under the table. Make sure you measure from the longest point of the mitre cut. Our frame measured 740mm x 2000mm. Set the circular saw to 45-degrees. Cut the ends of the support frame to length.
Lay out the support frame in its rectangular shape. Place the pieces of treated pine across the frame for support. Make sure the edges of the support frame are flush, then use a drill to screw the frame together.
Use the 3mm drill bit to drill holes through the merbau frame and into the pine supports. Repeat this for each end of the pine. Use 50mm timber decking screws to attach the pine supports to the frame, making sure that the corners are flush.
Place 1 leg in each corner. Use the 3mm drill bit and then the 4mm drill bit to drill holes through the support frame and into the leg. Repeat this for the 3 other legs.
Drill the 50mm timber decking screws into the legs via the outside of the support frame.
Set the circular saw to cut the four pine braces at a 45-degree angle. Measure and cut a 330mm long brace at a 45-degree angle. Repeat this step for the 3 other braces.
Place a pine brace as close as possible to the leg of the table. Use the 4mm drill bit and then 6mm drill bit to pre-drill two holes at both ends of the brace. The holes need to go through the pine and into the support frame. Repeat this for the three other braces then drill 75mm batten screws to secure each to the support frame.
Place the frame onto the underside of the tabletop. Make sure it's centred and the overhang is even on all sides.
To attach the frame to the tabletop, screw the L-shaped angle brackets into place. The screws for this come in the same packet as the brackets. Use 2 brackets between the treated pine braces and at least 2 at each end.
Turn the table over. Place a timber offcut directly below where you will be cutting out the hole for the drinks cooler. Attach it with the drill and 40mm screws. This will hold the boards together when they are being cut out for the bucket.
Use a jigsaw to cut the hole around the pencil line. Keep the timber you cut out, it can be used as a cover when your drinks cooler is not in use and you want a complete table.
Use 120-grit sandpaper to sand the edges of both the hole in the table and the timber you've just cut out. You can hand sand or use the orbital sander to do this job.
If you want to be able to remove the drinks cooler and make the table complete, attach at least 4 butterfly cleats under the table on the long side of the hole.