Airtight joints from your tablesaw

CD6900.jpg
by Jim Heavey
My recent move to a new home halfway across the country was made even more nerve-wracking by relocating a complete woodworking shop to a new basement location with just a single 15-amp outlet. Given the limited power options, top priority went to getting my most versatile and indispensable tool—the tablesaw—up and running. In addition to ripping, crosscutting, beveling, and mitering, it also does a great job cutting a straight edge square to the face of a board, known as jointing. You need to do this when preparing boards for edge-gluing, where the mated surfaces must align precisely. 

It’s easy to imagine jointing the edge of a 2×4 on a tablesaw because the board already has two fairly straight edges. Guide one edge against the rip fence for the first cut, then flip the board around to joint the opposite edge.  

But what about a large slab with irregular edges, or a board with bowed edges (photo below)?

SM_1595.jpg
A curved edge must be straightened before edge-gluing boards to form a panel, or creating other project parts.

Even if you have a jointer, the size and weight of a slab makes it difficult to handle on edge. And removing only 116 " or less at a time takes many passes to true up a rough or severely bowed edge. In contrast, a tablesaw removes a wide swath in a single cut, while supporting the face of the board. The secret lies in a well-tuned saw, a sharp 40–50-tooth combination blade set precisely at 90°, and a jointing sled.

The simplest of jigs


A 12–16" wide medium-density fiberboard (MDF) panel makes a perfect jointing sled. The MDF provides what rough-edge stock lacks: a straight edge to ride against the rip fence. Cut the sled as long as, or slightly longer than, the workpiece. 

double face.jpg
Double-faced tape secures the board to the sled. A 2"-wide strip every foot or so should suffice. Use fresh tape each time to guarantee a strong bond.

First, affix the workpiece to the sled (photo above).  Hang just enough of the workpiece edge over the sled edge to provide a cut down its full length (photo below). The sled also acts as a backer board, preventing chip-out. 

SM_1617.jpg
Joint the edge that requires removing the least amount of material. This allows the most flexibility when cutting the stock to final width.

After the first pass, remove the workpiece, and peel off the tape. Joint one edge on any other workpieces you have, then set the sled aside. Finally, run the jointed edge of each board against the fence and rip them to final width. The result: boards with both edges jointed and parallel. You can’t do that with just a jointer. 

A tablesaw can’t take the place of a jointer when it comes to creating flat faces on twisted stock. But, for putting a dead-straight edge on stock of nearly any size and shape, I prefer a jointing sled and tablesaw. Now that I have a place to plug it in, of course. 

Straight and true, and tapers, too

 MPC103294.jpg

Find yourself jointing on your tablesaw more than occasionally? This shop-made jig includes hold-downs to quickly secure a workpiece, and doubles as a taper jig to boot. Get the plan to build it, then watch Jim demonstrate its use.

Read more about

Tip of the Day

Woodworker's clamps secure glued edges, too

You can't top edge clamps for applying solid-wood edges, but like all quality tools, a fistful... read more