These J-bolts and foam blocks were the answer to a vexing problem: how to secure a plywood box to seat anchors in the bottom of the seat well?

Each of the two anchors was a short steel rod welded across the top of a small “box” in the floor, much like a bridge spanning a narrow canyon. The floor of the plywood box obscured the anchors, so there was no way to hold the bolts in place as the box was lowered into the well. What to do?…

J-bolts were the only solution I could think of, but figuring out how to immobilize them was a problem. They had to be in place, grasping the seat anchors and standing vertically, when I lowered the plywood box into the well.

The answer to the problem, arrived at after mind-numbing frustration, was to carve little blocks of plastic foam and push them into the little seat anchor “boxes,” insert the J-bolts into the foam, and align the bolts vertically. It worked---as I lowered the box, aligning the holes in its bottom with the upright bolts, the bolts eventually protruded through holes in the box’s floor. The foam also kept the bolt immobile while I attached washers and nuts. Another challenge was aligning the holes in the box with the seat anchors.

The main purpose of these thin bolts was to keep the plywood box from shifting laterally. They were not meant to be bombproof.