To begin assembling the optional ironing board, glue and screw together the two u-shaped pieces of plywood you cut in an earlier step (as shown on page 8 of the free woodworking plans). Then, attach (with glue and screws) the 12" x 16" piece to these two pieces, aligning one 12" side with the top of the "U" of the previous two pieces.
Second, glue and screw the ironing board piece onto the assembly by connecting it to the 12" x 16" piece. Align the back end of the ironing board to the bottom of the "U", and be certain you have a consistent 3/4" reveal on each side of the ironing board before you screw it in place.
Third, glue and screw one of the two 1-1/2" pieces horizontally to the shelving unit, aligning it so that the top edge is flush with the top of the third shelf. You can position this board anywhere horizontally along the third shelf.
Once this board has been glued and screwed to the third shelf, attach the other 1-1/2" wide board to the first one with glue and screws, aligned evenly with the first board on each edge.
Now, attach the 12" piano hinge to the face of these 1-1/2" pieces, with the knurl of the hinge flush with the top of the board. Screw into place with the included screws. Then, attach the other side of the hinge to the two U-shaped pieces of the ironing board assembly, aligning the top of the hinge with the top of the upper U-shaped board.
The entire ironing board assembly should now freely rotate up and lay flat against the shelving unit, and also rotate downward to a horizontal position (that will be maintained after we add the leg in the next step).


