Boiled part two, bentwood box lids and closures

Welcome to part two of the bentwood box build.

There are a couple of different ways to finish off the bentwood box. The first, and easiest is just to not have a lid. There are enough bases found without appropriate sized pieces for lids that it is possible that some were just open vessels to hold things. The vast majority of the illustrated pieces I have seen have lids however, and for most people lids are desirable or needed. So with that in mind we will address three lids, a friction fit, a snap lock, and a twist lock.

Friction lid

The first lid to look at I am labeling as a friction fit. It is designed to fit the body snugly but has no mechanical closure. This is also the style seen in manuscripts and document-able to the 14th century.

To make the friction lid you will need to cut a piece of lathe material wide enough to encompass the lid, as well as overlap the body of the box. The overlap will vary due to a combination of box size and personal preference. For the length of the lathe, you will need it to wrap around the body of the box and overlap securely. My preference is to keep the lines of the lid in line with the lines on the body. You will bend the lathe for the lid the same as the body, except the form you use will be the body itself. Wrap the lid and clamp it to the body to dry, once dry glue, clamp, and lace the lid as you did the body.

Snap lock

For the second closure we will look at what I term a snap lock. The snap lock is primarily found in the 17th to 18th century examples. Snapbox is a modern term used due to the sound it makes when it closes. The closures, or snaps, force the lid down and it closes with a loud snap. To open you pull the snaps apart and lift the lid up. There is a good bit of fine tuning to get a snapbox lid that is snug, but still flexible enough to open. The shape of the snaps really only require that they straddle the side of the box, go high enough above the lid to give you something to grab so you can spread them to open the box, and to have enough of an over hang to keep the id in place, but not so much you can’t pull them out enough to remove the lid. Historically they were often just a rounded tab with a notch cut in to hold the lid down. I went with a bit of creative flair to suit my taste, have fun with it and see what inspires your hand. The snap is cut with a notch to straddle the side of the box, often going to the bottom of the lathe on inside and out. Most of the examples I have seen have inset bases that are cut around the snaps, unlike friction lid boxs where the base and can be inset into the lathe or rabbited in.

I find putting a slight bevel on the snap, as well as the corresponding edge of the notches in the lid to be helpful in getting the lids to slide on and off.

My design for a snap.
historic example from Sunnfjord Museum dates to 1920’s

Swivel or twist lock

The third close is the twist lock. This is the least well documented of the closures, consisting of a reconstruction in the skansan open air museum in Stockholm, Sweden, and a line drawing attributed to the book, “woodwork in medieval novgorod”. The twist lock consists of a “T” shaped tab on one side that is fixed, and an inverted “L” shaped rotateing tab on the other side. The rotating tab is grooved and held in place through cords going through holes in the box. The fixed post is pegged to the body.

reproduction from the Skansan Open Air museum, Stockholm, Sweden

Once you have made the body and decided on the closure it is time to make your lid. If you are making a friction closure you will follow the instructions outlined above. Once you have a laced and dried band, sand as necessary to get a snug but not tight fit on the completed box. Once you have achieved a fit you like place your ring on the material you have chosen for the top and trace the ring, inside if you are doing an inset lid, or outside and inside if you are doing a rabbeted lid. Once your lid is cut and if appropriate rabbeted, secure the band to the top with pegs and begin thinking of finish options.

The lid for a snap or twist lock closure are constructed similarly.

Flip the box over and trace the top, for my personal taste I like a small overhang, about 1/2″ all around.

I also mark the box side and the lid at the point of the ellipse on both ends, this will be where the snaps or locks attach.

From here connect the lines on the lid for the points of the ellipse to get a line that should divide the box in two lengthwise. That is the center line of your closure, offset 1/2 the width of your snap or lock to either side.

To determine the depth of the cut measure in from your initial mark of the outside of the box, add the thickness of the wall of the box, and the width of the lock or snap.

Follow the marks you have cut out to make a notch in each end of the lid to hold the closure.

Next it’s time to turn your attention to the closures. The twist lock requires a little finessing and is great for use by people with limited hand strength, but is less well documented.

To start you will need to prepare two pieces of wood that are the equal in thickness to the width of the notch you put in the lid, and equal in length to the interior of the box from bottom to top plus double the thickness of the lid itself. One of the pieces will be twice as wide as it is thick, the second will be three times as wide as thick. The wider block will be cut to form the fixed tail end of the closure. Cut in on each side one third of the width of the block and equal to the height of the box plus thickness of the lid. The result should form a t shape similar to the one on the right of the following picture.

The second piece , the thinner of the two will be cut similar to the first except it will only have one of the arms of the t. This piece will then need to be worked so that the long narrow part is round. I start by removing the corners to make it an octagon and then sand from there. Once the lower portion of the piece is round you will round the back of the straight side. The right angle side can be left as is, or tapered to a wedge as personal preference dictates.

Top down of the pivoting portion of the closure.

At this point you will need to place the lid in position and use the piece you just completed to mark where the holes will go to secure it, and where to put the grooves that the cords will ride in to allow it to rotate.

At this point I will drill two holes per groove for the cord to pass through. I prefer to set the holes inside the diameter of the round part of the swivel, this helps to keep the cord in the channel.

Once your holes are drilled test fit the swivel lock in place to see it is high enough to clear the lid and that it rotates freely. Once you have adjusted the lock to rotate smoothly you can lace your cord to keep it in place and then glue and dowel the fixed portion of the closure. A slight bevel to the underside of the arms of the fixed side of the Closure is helpful. You may also find it hard to open if your tolerances are tight. I have found that beveling the underside of the lid from the notch back to the edge helps to get the lid to close snug to the body and still open with minimal struggle.

From here both the snap lock and swivel lock lids will need a handle attached, any last minute touch ups and then on to your finish of choice. I have used polyurethane and boiled linseed oil and of the two I refer the oil. The polyurethane is a tougher finish but it is also a thicker finish and may effect your closures. Oil is not as durable of a finish but it is easy to refresh as needed.

I would love to see your efforts if you try to make a box of your own. Good luck and May you always be worthy of your dreams.