My tool holder design is a reflection of my interests in electronics and modern materials. As such, I decided to incorporate an appropriate “found object” into my design: a discarded circuit board that had been made into a novelty clipboard…
I was able to remove the clipboard hardware by deforming the rivets mechanically, using a pair of needle-nose pliers. I then explored how I might cut the circuit board down to a smaller size. In my search for the best method, I learned that circuit boards are primarily made of fiberglass, and cutting them is hazardous because it generates glass-wool fibers that should not be inhaled. The fibers are both irritating and carcinogenic. The boards are best cut on a table saw with a diamond blade, and then the edges need to be refinished.
These findings convinced me to use the circuit board at its original dimensions–11-21/32 in. x 9-1/2 in. x 1/16 in–as the sliding-lid panel of an acrylic box. I visited T&T Plastic Land in Tribeca to look at samples of materials and settled on 1/4-inch fluorescent-green acrylic for the walls and dividers of the box. (T&T Plastic Land also sells a variety of acrylic boxes and solid shapes, including gems, that are a lot of fun!)
I developed a design that would accommodate tools of various lengths and widths by making the compartments staggered in length. The dimensions of the pattern pieces were as follows:
11-5/16 x 9-1/4 in.
Side where lid slides out:
9-1/4 x 2-1/4 in.
Remaining 3 sides:
11-13/16 x 2-1/2 in. (qty: 2)
9-1/4 x 2-1/2 in.
Five dividers inside the box:
6-3/4 x 2 in.
6-1/2 x 2 in.
6-1/4 x 2 in.
6 x 2 in.
5-3/4 x 2 in.
2 x 2 in. (qty: 4)
1-13/16 x 2 in.
1-1/2 x 2 in.
After carefully cutting out my foam core at all of these dimensions, I assembled them into a final prototype.
I then explored how the piece would be created in acrylic. While the acrylic can technically be cut on a table saw, it leaves the edge too rough for joining. To produce the smoothest possible edges in preparation for joining, I learned that it’s best to cut the pieces with a laser. It is also important to know that the process by which acrylic pieces are joined is technically not an adhesive process. Instead, it is known as “solvent welding” because the acrylic is softened at the interface of the two surfaces, causing the polymer chains to intertwine across the original interface, which literally disappears. The name “acrylic” is only partially accurate. The IUPAC name for the material used is poly(methyl 2-methylpropenoate), which is abbreviated as PMMA for Poly(methyl methacrylate).
TAP Plastics is a West Coast acrylic vendor whose excellent website and instructional videos provided a solid overview (especially their video “How To Glue Acrylic”) According to them, the best product to use for my project would probably be IPS Weld-On 4, which contains methylene chloride and methyl acetate. (See here for other types of plastic cements offered by TAP Plastics).
The reason a table saw could not be used to cut the pieces in preparation for solvent welding is related to the method of application of the IPS Weld-On 4. A small amount of the liquid is transferred from the source container to a “hypo-applicator,” a squeeze bottle with a 25-gauge blunt needle that’s 2 inches long.
The liquid is clear and runny. It does not fill gaps as some glues would, and it’s not applied to the surfaces to be joined. Instead, the surfaces to be joined are placed in position, and the needle is run along the edge of the joint, depositing a thin line of liquid. This is drawn between the two surfaces by capillary action (this only occurs with smooth edges, which is why a laser-cut edge is preferred over a sawed edge)! In a few minutes, the join is achieved, but has to set for several hours as the remainder of the solvent evaporates.
Here are several photos of the completed tool holder, which is fun to use and turned out nicely. The play of light on the acrylic is just as I’d hoped. It also accommodates all my tools very well.
Thanks for reading about one of the many tool boxes we have made this year!