|Project by SawdustTX||posted 10-01-2015 04:16 PM||5620 views||1 time favorited||2 comments|
Needed a 40” deep by 14 foot span countertop to support over 300 pounds of Audio gear in our church. The original builder installed counter had sagged an inch in the middle, so I wanted to build something seriously stout to replace it.
After much reading on LJs, I went with a torsion box of 3/4×1 1/2” ply ribs spaced 8” on center with half-slot joints, and sheathed in 3/4” ply top and bottom. Assembly was made more challenging by how warped the plywood was two days after bringing it home from the box store. Love the torsion box design – it ended up flat as a pancake!
I added some screw blocks within the grid so I could screw clamp the middle of the skins down during glue-up, and for wire pass-through holes.
To be able to transport this beast, I built it in two 7 foot long sections, then joined them onsite at install, with a center post support recessed 8” back from the leading edge of the counter.
Formica laminated, with a final one inch wide “bridge” strip installed after the counters were joined to create a seamless surface.
Next time – I’ll use solid wood for the ribs, and thinner skins, probably 1/2”.
Now I need to find time to make a couple torsion box tabletops for my shop!
Made a finger joint type jig for my miter fence and cut the half-slots with a dado blade.