Image 1 of 16
1. Build a 90-degree assembly jig (shown in blue) from 2x4s to keep the stanchions square while you nail. Screw the jig to a sheet of plywood. Short 2x6 blocks hold the header 1-1/2 in. off the table. To assemble the post, center the 2x4 in the middle of the first 2x6 and nail it with 3-in. galvanized nails, keeping the top ends flush. Nail the header onto the bottom of the vertical 2x6 (flush with the 2x4) with two 3-in. nails at two opposite corners.