Teak is a hardwood that has a light, golden color when first crafted. Similar to cedar, teak is both pest- and rot-resistant. Unlike soft woods, teak will not crack or splinter during cold snaps. With these characteristics, teak should be at the top of every woodworker's list when constructing an outdoor planter box.
Plane the teak board to a 1/2-inch thickness, using a planer.
Cut the 1/2-inch board into two 6 1/2-by-11 1/16-inch sides, 10 1 3/8-by-18-inch slats, and a 7 3/4-by-18-inch bottom, using a radial arm saw.
Route the top edges of the slats and the top and bottom edges of the bottom piece to 1/2-inch rounded edges, using a radial arm saw.
Sand all the pieces with a random orbital sander, first with the 80-grit and then the 120-grit sandpaper until the sides are smooth. Hand-sand the pieces and edges again with the 220-grit sandpaper.
Glue the sides and bottom together with a thin line of wood glue. Secure the sides into position with a nail gun and 1 1/4-inch nails. The bottom should be placed flush with the bottom edges of the side pieces.
Secure the slats. Place the top slat so that it is flush with the top of the planter and place two nails into both sides of the slat. Place the other slats in adjacent positions, going down the planter to the bottom, also placing two nails on each side.
Set the planter in a warm, dry place to dry overnight.
Fill in any nail holes with plastic wood dough, using a putty knife.
Sand all the edges of the planter by hand, using 200-grit sandpaper.
Dust off the sawdust from the planter with a wax tack rag.
Apply hot linseed oil to all surfaces of the planter. Leave the oil on for 10 minutes, then buff it off with a cloth diaper. Set the planter in a warm, dry place to dry overnight.