OSB Makes Cool Plywood Furniture—This Coffee Table’s Proof

Trim the top of the sheet

Use a track saw to trim the top 20-3/4-in. off the 4×8 sheet. Set it aside for the cutting of the corbel template and all the corbels (A).

Rip strips out of the rest of the sheet

Cut 16 strips of plywood measuring 2-1/2-in. wide from the remaining large piece of plywood. Ensure that the first strip is cut slightly wider, then cut it down to 2-1/2-in. so the painted factory edge or OSB tongue-and-groove can be removed.

Cut the stripes

On the miter saw, cut the 16 strips into the legs (B), top pieces (C), and spacers (D).

For 14 of the strips, make a single cut to separate the leg from the top piece. Ensure that the factory edge is positioned at the bottom of each leg (B) if your sheet is undersized like mine.

The last two strips will get cut into the 48 spacers.

Make the corbel template

Cut a 10-in. x 19-in. square out of the portion of the 4×8 sheet you initially cut off with the track saw.

Draw the corbel (A) template onto the sheet as in Fig. C above. Drawing a smooth arch is the most challenging part of this process. This can be accomplished by hammering a few nails at the endpoints and peak of the two arches, and bending a metal ruler along these points and tracing it.

After the corbel (A) is drawn, cut it out using a band saw or jigsaw. Give the edges a quick sand to ensure they are smooth.

Make the corbels

Trace and rough cut the last 11 corbels (A) out of the remainder of the sheet. Make them slightly larger than the template to ensure that, after routing, all of them will be nearly identical.

Use strong two-sided carpet tape or a couple of screws to secure the template on top of a rough-cut corbel (A). Then, using a router table fitted with a straight-cut router bit with a bearing at the bottom, rout the corbel (A) by running the bearing along the edge of the template, thereby replicating the template.

Repeat this process until you have 12 matching corbels.

Drill holes for the threaded rod

With all the pieces cut and shaped, it’s now time to drill 7/16-in. holes for the 3-8-in. threaded rod that will hold the coffee table together.

At the bottom of the four outside-facing legs (B) and at all four hole locations, on the two outside-facing top pieces (C), drill 1/2 inch deep holes with a 1-1/8-in. Forstner bit to countersink the nuts and washers on the ends of the threaded rod.

Next, construct a simple jig and clamp it to the drill press to center the 7/16-inch holes on the spacers (D). Using the same jig and setup, drill holes at the ends of each leg (B) and corbel (A).

Then, make another jig to drill the two sets of holes on the top pieces (C): one pair centered 3-3/4 inches from each end and another 11-1/4-in.

Set up the drill press carefully to ensure that the holes are drilled straight, centered, and aligned on all the pieces.

Sand the components smooth

After what fell like hours drilling holes at the drill press, it’s time to sand. Unfortunately, this is another long process. Sand and break the edges of six sides of every piece with 150-grit sandpaper. For those using OSB like me, take extra care to get the rough side as smooth as possible. Use whatever type of sander you have at your disposal, or a combination of several. Ultimately, I used a random orbital sander for most of the OSB, and a belt sander followed by a random orbital sander for the rough sides.

Apply polyurethane

Apply at least two coats of wipe-on poly to all six sides of every top piece (C), leg (B), corbel (A), and spacer (D). Give ample drying time and sand with 220-grit sandpaper between each coat. Besides providing some protection for the pieces, the poly also helps to bring out the multitude of colors of the OSB.

Assemble the table

Keeping the pieces in order is important, so attach the 48 spacers (D) using CA glue and 1-1/4-in. brad nails to the top pieces (C), legs (B) and corbels (A) that they will be assembled next to. Ensure that the spacer’s edges and 7/16-in. holes align with the piece to which it is attached.

After placing the table top pieces (C) face down on your bench, arrange the rest of the pieces in order. Make sure the outer legs (B) and top pieces (C) with countersunk 1-1/8-in. holes face outward.

When all the top pieces (C), legs (B), and corbels (A) are aligned at one end, thread the threaded rod through the hole in the top of the legs (B) and the outermost hole in the top pieces (C) with a nylon lock nut and washer tightened on one end. Add the washer and loosely tighten down the nut on the other side so there is still play in the rod.

Then, loosely thread the rods at the bottom of the legs (B), and another where the inner holes on the top pieces (C) align with the top hole of the corbels (A). And, thread the three rods on the other side.

Start tightening each rod little by little with a ratchet in one hand and an open-ended wrench in the other, stopping occasionally to ensure that the pieces are lined up. Use clamps and a mallet to move the stubborn pieces into alignment.

After you have tightened the threaded rod until you feel some resistance, but not so hard that the washer digs into the OSB, you can trim the threaded rod flush with the ends of the nuts using a hacksaw and file them smooth if necessary.

FAQ

How to finish OSB furniture?

To properly finish OSB furniture, seal its porous surface with two or more coats of polyurethane, epoxy resin, or, if painting, a primer followed by your chosen paint, sanding between coats with 220 grit sandpaper.

What lengths do threaded rods come in?

In general, threaded rods are available in 3, 6, 10, and 12-foot lengths, and can be cut to your specifications.

Are there different grades of OSB?

Yes, there are four OSB grades: OSB1, OSB2, OSB3 and OSB4 (though sometimes seen as OSB/1, OSB/2 etc.).

• OSB1 is suitable for dry conditions and interior general-purpose applications (including furniture).
• OSB2 is suitable for dry conditions and general interior use, but is also load-bearing.
• OSB3 is the most common grade used in the construction industry, a load-bearing board suitable for use in damp, humid conditions.
• OSB4 are a heavy-duty load-bearing board suitable for damp and humid conditions.