Adding curves to a box is a great away to create some visual interest. While this project focuses on making a uniformed, curved memento box, you can apply these same building principles, along with your imagination, to really make this project your own!
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Step 1: Mark & Cut Material for the Box Sides
In my case, I’m using walnut. My box will be a slight rectangle. The long sides will be 7”T x 2-3/4”W x 3/4"T. The short sides will be 5”T x 2-3/4”W x 3/4"T. Since I’m using rough walnut, I take the time to cut the pieces with the bandsaw, and then joint and plane the pieces to their final thickness. If using lumber from the big box store, it may only be necessary to cut the pieces to length and width.
Step 2: Sand the Inside Face of the Box Sides
When making boxes, I like to sand the inside faces prior to assembly. It will be easier to sand these pieces now than sand them after the box is assembled. I sand the inside face with 80 grit, 150 grit, and 220 grit sandpaper.
Step 3: Cut the Joinery for the Box
I place a ripping blade in my table saw. A ripping blade leaves a flat groove compared to a cross cut blade that generally makes a V cut. The blade height is approximately half the thickness of my workpiece.
I clamp a sacrificial fence to my miter gauge, allowing me to butt my work piece against the fence and push it through the blade. The sacrificial fence prevents any tear out of wood fibers so the cuts will be nice and clean.
A rabbet notch is cut on the ends of the long side pieces so that the short pieces can fit inside them.
Step 4: Make the Bottom of the Box
I chose a piece of walnut to serve as the bottom of the box. I cut it to a rough size of 7”L x 5”W. It will be cut to final dimensions later. The box bottom is planed down to 3/8” thick. If using box store lumber, 1/4" thick bottom is perfectly fine.
It is a good idea to sand the box bottom now, prior to gluing the box together.
Step 5: Cut Grooves in the Box Sides
With the ripping blade still in the saw, I make multiple passes to cut a groove in the inside face of the box sides. This groove will house the bottom of the box. I make multiple cuts until the bottom piece fits snuggly in the side.
Step 6: Fit the Bottom Into the Box
With the grooves cut, I measure the depth of the groove and mark it on the bottom of my box sides. I then use a ruler to measure the length and width needed for the box bottom. I like to leave approximately 1/16th of an inch of extra room for wood expansion and contraction. I then cut the box bottom to size.
Step 7: Assemble & Glue the Box
Using wood glue, I assemble the box by applying glue to the rabbets of the long pieces. I like to place a dab of glue inside the center of the groove in the short sides. But I do not put glue in the grooves of the long sides. Wood expands with humidity, but it does not increase in length. The glue in the short sides helps to keep the bottom in place, but still allows the wood to widen or contract through the seasons.
I apply clamps on the box until the glue dries.
Step 8: Mark & Cut the Lid
My lid is maple so I take the box and lay it on a piece of maple and mark out the size needed. I use the bandsaw to cut the lid to rough size, and then I joint and plane the board. I want the lid thickness to be about 3/4". The lid is then cut to final size so that it’s the same size of the box (5”x7”).
Step 9: Fit the Lid Onto the Box
I place a dado stack blade in my table saw so that I can cut grooves around the perimeter of the lid. The dado stack is the same width as the box sides. I cut all four edges so that the lid fits inside the box. This can also be done with multiple cuts with a ripping blade.
Step 10: Layout and Cut the Shape of the Box.
To make the curved sides, I take a thin scrap of wood and cut
little notches on each side. I then take a piece of twine and tie it to each groove, bending the stick. I place the stick on each corner of my box and trace a line for my curve. I do this on all four sides.
At the bandsaw, I cut the curves, staying just outside of my pencil lines. I’m using a 3/4” wide bandsaw blade. If I were to make sharper curves, I would switch to a thinner blade that allows for tighter curves.
Step 11: Sanding the Box
Using a spindle sander, I sand the curve on each side until I get to my pencil line. One tip to gauge your progress is to flip the lid around throughout the sanding process. This will help to see if your sides have the same curve or if you need to sand certain areas more.
It can be difficult to get a smooth finish with a spindle sander, so I hand sand the sides until they are smooth, working my way up to 220 grit. I also sand the bottom of the lid and any spots inside the box that need it. I also take time to round over the edges on the box and lid.
Step 12: Apply Finish to the Box
Using a wipe-on varnish, I apply multiple coats of finish to
the box and lid. After each coat dries, I sand it with 600 grit sandpaper before applying the next coat. Once I’m satisfied with the look and the finish is dry, I give it a light sanding with 2000 grit paper to make the box smooth.