Eight 12-inch lengths of 1/2-inch square steel rod were used to support the shelving (four per shelf). To align the steel shelf supports, laser lines were shot to locate the bottoms of both shelves. All studs were accurately located, edge-to-edge to ensure drilling into their centers, then straight rips of plywood were screwed along the horizontal laser lines (photos, left and right).
Oversized 3/4-inch by 3-inch-deep holes were drilled to allow room for epoxy adhesive around the 1/2-inch square dowels. The hole centers were 7/8 inch above the shelf bottom lines (photo, left). Here (photo, right), the steel rod is dry-fit in place resting on a 5/8-inch spacer block (to raise the rod up to its actual height) at the wall and clamped to a temporary vertical support stick.
Vertical support sticks (pinned at the base with brads to keep them from wandering) and spring clamps were used to hold the steel rods in place while the epoxy set up. Each dowel was leveled, its location scribed on the support sticks (photo, left). Once all support rod locations were dry-fit and triple-checked for level and true point-to-point sight lines, the epoxy was installed. A skinny putty knife and stick was used to fill the hole with epoxy (photo, right).
The steel rods were inserted into the epoxy (photo, left), then spring-clamped to the support sticks and re-checked for level (photo, right).
As the epoxy set up, the steel rods were repeatedly checked for level (photo, left) and square (side to side perpendicular to the drywall). The epoxy squeeze-out was carefully cleaned away with a narrow putty knife while it was still liquid so it wouldn’t interfere with shelf installation later, when it had hardened (photo, right). The author notes the West System Six10 epoxy adhesive used does not slump and has a generous working time of 45 minutes or so.
Before the pre-built 3- and 6-foot “sandwiched” sections were permanently joined into the L-shaped shelf, the individual shelf lengths were placed on the dowels and scribed true to their respective walls (photo, left). First, they were squared to each other at the corner joint (making sure the L-shape was 90-degrees), then scribed to a few bulges in the drywall where the wall studs weren’t perfectly straight (photo, right).
Also, before the shelves were glued up, the dowel locations were marked on the shelves in order to properly locate additional spacers during final installation of the shelves (photos, left and right).
Intermediate spacers were installed in the 8/4 shelving “sandwich” well to the right of each dowel location, allowing the shelving to be slid leftward into place over the dowels (photo, left). A pair of spacers splined the butted shelf joints together (photo, right).
With remaining spacers in place, the shelf assembly was glued (with yellow glue) and clamped together.
Once the glue had dried, the shelf’s 6-foot leg was easily slipped over the three dowels on the long wall and then the L-shaped unit was slid leftward over the dowel on the short wall (photo, left). The shelves were pinned in place to the walls using just two trim-head screws per unit, toed in at the back edge and capped with wood dough (photo, right).