Tuesday, February 17, 2015

Custom Fitting A Box To House An Object

Our library collections hold books, but also other three-dimensional objects. These items (and even the books) are not always regular shapes that fit into commercially made housing. Sometimes we need to either build a box from scratch or adapt a purchased box to house these items. For example in 2012, we created housing for a collection of canes that required some adaptation to their rectangular boxes. There are many ways to adapt a box to hold objects, and a variety of materials can be used: Ethafoam, Volara, archival corrugated board, Tyvek, archival tissue paper, among others.

Recently a wooden cross from World War One needed special attention to house it safely. I documented the steps I took to adapt a commercially made box and have included a diagram to illustrate the mathematics of the interior boxes.

I started with a commercially purchased box that was slightly larger in all dimensions than the item.

My goal was to create a recess for the cross within the box by making interior boxes of archival corrugated board.

These interior corrugated boxes are designed to fill empty space to create the recess. They are glued shut and maintain stability by including a top (as well as a bottom), though the top isn’t strictly necessary. I calculated and constructed them based on the methods used in Andrea Krupp’s great instructions for the corrugated clamshell box, which I learned from Hedi Kyle.

When designing these interiors keep in mind where and how the item is stored (horizontally or vertically), how frequently it is handled, and how it can be removed from the box.

To create the interior corrugated boxes here are the steps I took.

1) With the cross in place, I measured the four quadrants of empty space on the box bottom. I subtracted ¼ inch from the length and ¼ inch from the width of each of those rectangles (this gives some breathing room to the cross for removal). Using the dimensions of the box bottom I adjusted my calculations so the two boxes on the left side were equivalent to the boxes on the right side boxes (as mirrored pairs). This simplified things by requiring only two sizes of boxes. I now had the length (L) and width (W) measurements. I then measured the large outer box depth for the thickness (TH) measurement. This should be very slightly lower than the box side, but keep in mind any additional layers of material (Volara, paperwork, etc.) that need to go over the top before the lid goes on and account for that in your thickness measurement.

Consulting the diagram I have drawn out while reading further might be useful.

Definitions used on the diagram:

L = length
W = width
TH = thickness
BT = board thickness
Solid lines = cut
Dotted lines = score/fold
Grey areas = cut away/remove
Tab = 1 inch

I chose to create a 1-inch tab for gluing my box together. Smaller boxes could certainly be made with thinner tabs.

Using my measurements (L,W,TH) and 1/8 inch archival corrugated board, I cut a rectangular board based on these formulas:

Height of board = 2TH + 2L + 1Tab + [4BT or 1”]

Width of board = 2TH + 1W + 2Tab + [3BT or 1”]

2) Then using the cutting and folding diagram I measured and drew out my box onto the board and cut.

A few tips:

Start measuring and marking lines from the same square corner (both horizontally and vertically).

It is easier to bend with the corrugations so keep that in mind when choosing which way to orient the board, though either way does work.

I used a scrap of board as a jig to mark my BT (board thickness) as I drew these lines out. You could laminate multiple pieces of board together to create a jig for easier measuring.

As you see on the diagram I have added a board thickness to each dimension (W, L, TH) to account for the walls and folds. I didn't add the board thickness to the three most exterior tabs since those tabs needn't be a precise size.

3) Once the box is cut out gently score the lines with a bone folder, and fold them up. Then the tabs need to be delaminated before gluing them down.

This board is made of three layers: flat paper, corrugated paper, and then another layer of flat paper. The corrugated paper in the middle of the tabs will be cut away and the two flat layers will be glued to the adjacent side, one on the interior and one on the exterior making for a strong and square attachment. You will be separating seven tabs: the four to create the box bottom and the three to attach the top to the sides.

4) Gently using a microspatula and/or an awl separate the layers.

You can also gently use your hands to pull these layers apart once you get them started.

5) When they are separated carefully bend the flat layers aside and cut the corrugated piece away.

6) Lay waste paper under the two tabs and apply glue, then fold up the side to create the 3D box and press into place. Do this to all sides of the box creating the box bottom.

7) Now prior to gluing down the top cut away two small areas in the interior tab coming off the top.

This will allow the tab to set inside the box without hitting the interior side tabs. Glue up all interior tabs (even though they may not adhere) and the exterior tab coming off the box top. Close box and press. Then glue up the remaining exterior tabs on the two sides and press.

Here are the first two boxes in place to check the fit.

After the four corrugated boxes were made, I set them within the big box. I checked the fit of the cross within the space to make sure all was as it should be. Then I cut Volara to fit into the recess so the cross was laying on something softer than the board. The friction between the Volara and the cross helps hold the object in place.

8) Once the parts were cut, assembled, and the fit tested, I first glued the corrugated boxes, then the Volara, into the box bottom with PVA.

I weighed down the corrugated boxes to ensure good adhesion.

After everything was dry the cross went into its new housing ready for the shelf.

Interior compartments can be constructed in all sorts of ways and materials. They can be adapted for use in basic or deluxe boxes. This is one method, and if you have another you would like to share, we’d love to hear it!

Written by Stephanie Wolff

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