Rout the block to match the blade with a simple dishing jig
Full disclosure: I collect kitchen knives the same way I do hand tools in my workshop. I bought the ulu knife kit because I was hooked by the shape of the blade. I'm a little surprised that my ulu has become my go-to knife for slicing and dicing.
Designed by the Inuits, this little knife has been used for everything from skinning game, to haircuts, to trimming snow blocks for igloos. Seal isn’t a regular part of my daily diet, but I’ve found that this curved blade excels at dicing vegetables and herbs, and trims meat as well as my pricier chef’s knife. The handle’s position above the blade provides a significant mechanical advantage when chopping hard vegetables and frozen foods.
To make full use of my new knife, I made a double-sided cutting board to match the blade. The concave face keeps finely-chopped ingredients from spilling over the countertop. The flat side serves for slicing meats and cheeses.
The knife/block pair is a great excuse to raid your scrap bin. With help from a few simple jigs, you can make this combo in few hours.
Different curves for blade and board
To allow the knife to pivot, the diameter of the block’s concavity is greater than the blade’s arc. The 12"-dia. routed dish works well with Woodcraft’s 41⁄2"-radius knife.
Instead of sandwiching the two tangs between matching wood scales, I plunge-cut the slots with a multi-tool and 3⁄8"-wide blade. After layout, I drilled a series of holes, set my saw guide, and sawed out the waste. I then used a jigsaw blade to clean out the slot and work up to my line. When the tangs fit, glue them in place with epoxy. Temporarily mounting the exposed blade in a holder saves time (as possibly fingers) as you complete the knife.
Taking the plunge. Set shims under the guide and make two plunge cuts. A countersunk magnet keeps the blade from jumping off the guide.
Rout this way. Clamp the blade between 3⁄4"-thick MDF shields to create a holder for routing the handle. Keep the scrap in place when sanding and finishing.
Make a dishing jig to rout the block
Turning the concavity might be faster, but this jig makes routing a perfectly-sized dish nearly fool-proof. The turntable rotates on a 5⁄16"-dia. dowel that's glued into the base. Attaching sandpaper to the turntable prevents the block from spinning should the bit catch the block. Use double-stick tape or pin nails to affix the block to the turntable. The short runners and notched platform allow the router to ride the curve more closely.
One jig makes another. Cutting the dishing jig's arced sides with a trammel ensures that the sides are smooth and symmetrical. Rout the arc in 1⁄4" increments. Tack the sides to a backer so that the parts don’t shift at the end of the cut.
Doing the dishing. This jig creates a 7 1⁄4" × 11⁄8"-deep cavity in 11⁄2" thick block. I used a bowl bit, but any roundnose bit will suffice. To control chatter, use a 1⁄2"-shank bit and set the speed to 13,000 RPM. To reach the very bottom of the dish, I set bit lower in the collet and finished up with super light passes.
Routing in the round
Rout the recess from the outside in. To do this, position the platform so that the bit clears the block, adjust the bit for 1⁄8"-deep cut, and then pivot the platform until the bit's bottom edge makes contact. Rotate the turntable 360° before shifting the platform. To minimize cleanup, overlap your passes. After routing, use the jig to hold the block while you clean up scallops left by the bit.
Smooth it out. Use a curved scraper to shave off any high spots. A wedge-shaped block keeps the turntable from spinning.
Sand then seal. A multitool equipped with a sanding pad, followed by a mop sander, quickly erase remaining tool marks. Finish-sand through 320 grit, and then seal with your favorite cutting board finish.