Tag Archives: hot glue

Who invented the hot glue gun?

The hot glue gun is one of the main tools in a props person’s arsenal. Some people love them, some despise them, but at one point or another, all will use one. They can also be referred to as hot melt glue guns and hot melt adhesive guns. They use sticks of hot glue, or hot melt adhesive, thermoplastic adhesive, or thermoplastic cement, depending on your preferred nomenclature.

So who invented the hot glue gun, and how did it come to be? If we Google the phrase “who invented the hot glue gun”, we find the following results:

Google search for "Who invented the hot glue gun"
Google search for "Who invented the hot glue gun"

The first few results list “Robert Brooklyns” as the inventor. Let’s see what a Google search on him turns up:

Google search for "Robert Brooklyns"
Google search for "Robert Brooklyns"

When I did the search, Google returned around 83 results. All of them basically parroted the same sentence. Basically, one site (Answers.com is my guess) made this completely uncited statement, and it has been echoed throughout content farms and superficial sites across the internet. No one with this name shows up in a deeper search through books or patents, which seems surprising, given how important the hot glue gun is.

You may have noticed in the first image that a result shows up with an obituary for George Schultz, whom the Boston Globe calls the “inventor of the first industrial glue gun”. According to the Globe, he founded Industrial Shoe Machinery in Boston in 1954, which he sold to 3M in 1973. Somewhere along the way, he invented the Polygun, the “first industrial glue gun”. 3M manufactured hot glue guns under the name “Polygun” until 2006, when they changed the name to “Scotch-Weld”.

The earliest related patent I could find for George Schultz was for an Apparatus for Dispensing Thermoplastic Material. It was issued on June 2, 1971.

George Schultz's glue gun
George Schultz's glue gun

The diagram shows a glue gun with a trigger, but the glue is held in an internal reservoir rather than fed through as sticks. While Mr. Schultz was certainly the inventor of a hot glue gun, he was hardly the inventor of the hot glue gun.

The Wikipedia article on adhesives has an uncited claim that thermoplastic adhesives were invented in the 1940s by Proctor and Gamble by a man named Paul Cope. Again, this becomes hard to verify, because innumerable content farms merely copy the Wikipedia article, and most of the search results are variations of this same initial claim (many have the same exact wording). At least we can find evidence that Paul Cope was a real person who worked at Proctor and Gamble. He even filed a number of patents having to do with improvements in packaging. Whether he had anything to do with thermoplastic glues seems to be a moot point, as mentions of thermoplastic adhesives can be found in literature and patents much earlier than that, as far back as 1907.

Perhaps the earliest proto-hot glue gun was this Plastic Extrusion Gun created by William R. Myers and Albert S. Tennant in 1949. The device was created for melting plastic and extruding it onto fishing hooks to manufacture fishing flies. The plastic was fed into the device as ribbons rather than as sticks, and it did not use thermoplastic adhesive. Regardless, many of the parts and components of a modern hot glue gun are there, and later inventors referred to the Myers and Tennant plastic extrusion gun quite a bit in their patents.

Myers and Tennant Plastic Extrusion Gun
Myers and Tennant Plastic Extrusion Gun

 

 

In 1965, Hans C. Paulsen, working for United Shoe Machinery Corporation, was granted this patent for the Portable Thermoplastic Cement Dispenser. It predates Schultz’s invention by six years.

Paulsen's portable thermoplastic cement dispenser
Paulsen's portable thermoplastic cement dispenser

 

That December, Popular Science ran an article about this glue gun, named the “Thermogrip”. The article proclaims “A black plastic pistol with an electrical heating element and an aluminum nozzle that extrudes hot-melt glue is one of the newest tools for home and shop.” I find the Thermogrip notable for its use of glue sticks and for the fact it was marketed and sold to home users, as opposed to previous glue guns which were tailored for specific industrial processes. I would consider this to be the first “hot glue gun” in the sense which we are most familiar today.

As with any invention, it is perhaps futile to try and trace its invention to a single person. The hot glue gun relies on a number of parts and components, such as the development of thermoplastics, the evolution of plastic extrusion guns, and the societal need for a portable device which accomplishes all of this. The modern-day glue gun we all know and love has any number of features and improvements which were not present in the earliest iterations.

That said, the hot glue gun was certainly not invented by a (perhaps imaginary) man named Robert Brooklyns, and hot glue was not invented by Paul Cope. This goes to show how easily an unverified claim can infiltrate the Internet. Remember kids, more search results in Google does not equal more reliability. An unsourced claim is still an unsourced claim even when it shows up on thousands of websites.

Review: The Prop Builder’s Molding and Casting Handbook

The Prop Builders Molding and Casting Handbook
The Prop Builder's Molding and Casting Handbook

In Thurston James’ second book, he tackles the subject of molding and casting for prop makers in more detail. The Prop Builder’s Molding & Casting Handbook guides you through the most common materials and methods used in many prop shops. Because of its specific focus (and better organization), this book is far more successful than his previous Theatre Props Handbook, which, as I mentioned in my review, meandered through disparate topics with no way to quickly find information.

Though written in 1989, the methods described in this book still hold true today. Though the range of materials we can use today have grown dramatically, they remain improvements and new formulations to older materials whose predecessors can be found in this book.

It remains one of the most widely recommended books for molding and casting props because of the unique niche it fills. It describes the most common materials and methods used in props shops and by hobbyists; these materials are used because of their cost, ease of use, availability, and proven results. Books on molding and casting for manufacturing and industry are more focused on specific or specialized materials, and they aim for a level of consistency and cost efficiency which the prop artisan would never possibly need. Shaving a tenth of a cent off the cost of a casting makes a difference if you are casting ten thousand pieces, but it will be impossible to notice if you are only making ten.

James seems to have had an epiphany in shop safety between this book and the last, as he now presents clear and accurate safety precautions in the beginning of the book, and continues to reiterate them throughout. In his Theatre Props Handbook, safety precautions were nearly nonexistent.

The book does a good job of covering the generalities of mold making and casting. It discusses the model and its preparation, and defines a number of necessary terms, such as undercuts, release agents, mother molds and the like. It describes the considerations of making a mold of your specific piece, and breaks the various molding materials and casting agents into categories. In a way, it describes the process of choosing your materials in an almost flowchart-like manner. If you know what your model looks like, and you know what kind of properties and appearance your castings need, then you can narrow your choices of mold material and casting material down to a few choices. In the book, he describes over thirty of these material choices.

The bulk of the book is used to guide you through the specifics of working with each of these materials. Specifically, he talks about plaster, alginate, latex rubber, and silicone rubber (RTV) mold-making. The casting materials he describes include latex, neoprene, papier-mâché, Celastic, fiberglass (GRP), hot melts (such as wax, plasticine, hot melt glue and hot melt rubber, breakaway glass, thermosets (specifically polyester resin), water-extendable polyester, and urethane. He also has a section on casting with hardware store products, like caulk, autobody filler, water putty, and several others. Finally, the last section of the book describes vacuum forming and how to construct a vacuum forming machine.

Five Prop Quick-Fixes

Sometimes you need to fix things right, and other times, you need to fix them right now. Here are four things which prop people rely on to fix a prop when the audience is already seated and the curtain is about to go up.

Hot Glue

hot glue gun
Hot Glue Gun

It’s a common prop adage that “anything can be fixed with hot glue.” That’s true in many cases, and the fact that it cools in minutes (sometimes seconds) and is removable makes it a great candidate to hold two things together at the last minute. When you need to separate the items, just peel them apart. Keep in mind that it is not structural, and it will not come out of most fabrics.

Gaff tape

gaffers tape
Gaffer's Tape

Gaff tape is short for gaffer’s tape, so named because of its use by gaffers to tape down cords and cables. It’s like duct tape for prop people; unlike duct tape, it leaves no residue when removed, and most importantly, it comes in black, so it disappears on stage (and can be used in a pinch to make other things disappear on stage as well).

Wire

wire
Wire

Wire of all different thicknesses is great for tying things together when adhesives just won’t stick. It’s also key for hanging things from walls or ceilings. With glue, there’s always a chance the weight will prove too much for the bond and cause the prop to come crashing down on someone’s head.

Mortite

Mortite rope caulk
Mortite Rope Caulk

Mortite, or rope caulk, is a type of caulk that will not dry out. It’s great for keeping glasses from sliding around on a tray, or vases from toppling off of a shaky table. It also makes it very easy to remove the prop when needed, as when an actor needs to pick up the vase during a scene.

5-minute Epoxy

5 minute epoxy
5 Minute Epoxy

I prefer the kind that comes in the easy-dispense tubes, which makes this product as idiot-proof as possible. Epoxy resin is a liquid which comes in two parts; when mixed, it sticks to many materials and becomes rock-hard. As the name implies, 5-minute epoxy hardens in 5 minutes, making it one of the quickest ways to get a very secure bond.