Conserve O Gram August 2008 Number 17/5 How to Make a Board Crate

Crates and for shipping museum objects rene core. They are not archival and not as can be made from a variety of materials. Poly- strong as either the honeycomb central core ethylene, and cardboard are three of the panels or the tri-walled cardboard. most prevalent materials. The crate must be strong enough to ensure the contents are safe . Hot melt adhesive is the most con- during handling and shipping. The more often venient material to use for the rapid and strong a crate is used, the stronger it must be. If a construction of the paper board crates. Choose crate is repeatedly used, then the materials used a hot melt adhesive with the longest “open” to construct it should be able to withstand time possible to provide flexibility during con- shock, vibration and mishandling. When a struction. “Open” time refers to the length of crate is only used once or twice, it can be made time the adhesive is tacky and workable provid- from materials that are more easily worked. ing an adequate bond. Use archival quality materials that come into contact with the museum object. • Low melt adhesive such as 3M Products 3792LM is a clear adhesive. It has an open Materials Needed to Make the Crate time of about 40 seconds.

Crate Walls. These will be fabricated from one Skid Materials. These are needed to create a of the following and should be cut with a band pedestal that raises the crate off the floor. These saw, bench saw or a sharp knife are essential to allow the crate to be lifted with a forklift or jack. • 350 Board – this is tri-walled cardboard made of three layers of corrugated card- • Rough cut lumber - this can be 4” x 4” or board adhered to a 5/8” approximate thick- 2”x 4” ness. It is not an archival grade board. This provides a very strong crate. Filament adhesive tape. This is 2” wide, high performance, pressure sensitive, filament rein- • Honeycomb central core panel - has each forced tape used to adhere the top of the crate face of the board covered with cardboard in place. and contains a central core of honeycomb board. The panel is ½” thick. An archival Calculate the Crate Size grade of this type of panel uses the brand name Tycore. Determine the outside dimensions for the crate. If double boxing, calculate the size of the • Foam cored boards - are clay-coated inner crate by this method. Calculate the outer boards bonded to a rigid extruded polysty- crate dimensions (using the exterior size of the National Park Service Conserve O Gram 17/5

interior crate as the object size) and eliminate pallet jack or forklift. The two skids need a the allowances for . minimum of 28” between them. (4” x 4” x 38-1/4”) Table 1. Determining Crate Size Dimensions Length Width Height Assemble the Crate Size of the object 32” 29” 14” Allow 2” for 4” 4” 4” • Place the crate bottom board on a flat sur- tissue and bubble face. Mark placement lines for the skids. wrap on each side Run a large quantity of hot melt adhesive Allow 2” for ure- 4” 4” 4” thane foam pad- on the skid and then place the skid on the ding on each side bottom board at the marked area. When Sub total 40” 37” 22” the adhesive has dried, turn the board over. Allow 5/8” for 1-1/4” 1-1/4” 1-1/4” Use nails or screws to reinforce the bond of the depth of the the skids to the bottom board. board on each • With the skids on the under side, run a side bead of adhesive on the crate bottom board Total outside 41-1/4” 38-1/4” 23-1/4” along one of the outside edges. Position crate dimension a side board in place and hold for a few seconds until the glue reaches a hardened state. (Scrap of heavy board can be set at a Cut Boards to Size right angle to support the side wall board until it dries.) Repeat for the second side Using the examples shown in Table 1: wall. • Test fit the end panels to verify the accu- • Cut one top and one bottom board of the racy of their cuts. To adhere the end wall same size. These are cut using the total in place, run a bead of glue along the crate length and width dimensions of the crate. bottom and along the inside edge of the ( 41-1/4” x 38-1/4”) two sidewalls. Place the end panel in posi- • Cut two side wall boards of the same size. tion. Use masking tape to hold all boards The sidewalls sit on the crate bottom board in position while the adhesive solidi- and are covered by the so do not need fies. Repeat with the other crate end. To the two allowances. These boards are cut strengthen the crate, run a bead of glue using the sub total height and the sub-total along all seam joins. length dimensions. (40” x 22”) • Cut urethane foam padding to fit the inte- • Cut two end wall boards of the same size. rior of the crate. Place the bubble-wrapped The end walls sit on the crate bottom board object in the crate. The urethane foam and are covered by the lid so do not need liner dampens the shock and vibrations the two allowances. These boards are cut experienced by the wrapped object. Use using the sub total width and the sub-total sheets of it to hold the wrapped object height dimensions. (37” x 22”) in place within the crate. If the wrapped • Cut two crate skid feet of the same size. object can move in any direction, use addi- These are placed on the bottom of the tional foam to secure the position. crate to lift it above floor level for use of a • Place the crate lid on top of the crate and

2 How to Make a Paper Board Crate National Park Service Conserve O Gram 17/5

secure it in place with 2” wide pressure Selected Sources sensitive . Place one or two strips of tape in place at the center point McMaster – Carr of each of the four sides. Then complete 6100 Fulton Industrial Blvd. SW the taping. The tape should run from the Atlanta, GA 30336-2853 top of the crate over the joining edge and Phone: 404-629-6500 down the crate sides approximately 6 to 8 www.mcmaster.com/ inches. The tape should overlap making a completely sealed edge. Packaging Services of Maryland • Indicate which end it up with an up arrow 16461 Elliott Pkwy and note the contents are fragile in large Williamsport, MD, 21795-4082 letters. Phone: 301-223-8622 • Mark a dotted line with a permanent FAX: 301-223-8247 marker on the upper surface to alert the Toll Free Phone: 800-223-6255 recipient to the preferred opening proce- www.psimd.com dure. Using this method to open the crate allows for reuse. Alice Newton Supervisory Museum Specialist, Harpers Ferry Center For additional information, see COG 17/3. National Park Service Harpers Ferry, WV 25425

Figure 1. Paper Board Crate

The Conserve O Gram series is published as a reference on collections The series is distributed to all NPS units and is available to non- management and curatorial issues. Mention of a product, a manu- NPS institutions and interested individuals on line at . For further information and guidance con- Park Service. Sources named are not all inclusive. It is suggested cerning any of the topics or procedures addressed in the series, that readers also seek alternative product and vendor information contact NPS Park Museum Management Program, 1849 C in order to assess the full range of available supplies and equipment. Street NW (2265), Washington, DC 20240; (202) 354-2000.

How to Make a Paper Board Crate 3 How to Make a Paper Board Crate