If you are looking for a versatile adhesive used since ancient times, animal glue is what you need. Made by boiling animal connective tissues, this adhesive has a rich history dating back to at least 7000 BC. People used animal glue for a variety of purposes, including as a coating, sizing, in decorative composition ornaments, and as clarifying agents.
Animal glue is formed through the hydrolysis of collagen from skins, bones, tendons, and other tissues of animals such as horses, cattle, rabbits, and fish. While synthetic adhesives have largely replaced animal glue in many applications due to their convenience and cost-effectiveness, it remains a popular choice for making and restoring violin family instruments, paintings, illuminated parchment manuscripts, and other artifacts.
In this article, we will explore the history of animal glue, discuss the various types of animal glue, the advantages/disadvantages of this type of glue, and how it works. Additionally, we will delve into the question of what is the strongest type of animal glue available on the market today.
History of Animal Glue
Animal glue, one of humanity’s oldest known adhesives, has been crucial to various cultures and civilizations throughout history. The origins of animal glue trace back to prehistoric times. The first evidence of its use in cave paintings in Lascaux, France, dates back to around 15,000 BC. Paleolithic hunters are thought to have discovered the adhesive properties of animal collagen while cooking animal parts, setting the stage for its future use.
During the rise of ancient Mesopotamia, between 3000 and 2000 BC, glue became integral to various industries and daily life. Mesopotamian craftsmen and artisans started using animal glue extensively in their work. Animal glue was employed for diverse purposes, including joining stone and wooden implements, mending broken pottery, and producing ornate inlaid works of art. Woodworkers used animal glue to create sturdy furniture and affix precious gemstones and metals to wooden bases.
During the time of Ancient Egyptians, around 1500 BC, craftsman used animal glue in furniture, burial tombs, and even the construction of the iconic pharaohs’ chariots.
The use of animal glue was not limited to Egypt, however. Ancient Greeks and Romans used it for woodworking, veneering, and marquetry, showcasing its versatility and utility.
In East Asia, specifically in China during the Han Dynasty (206 BC–220 AD), animal glue was a binding medium for creating stunning lacquerware. Over time, it became an essential part of the Chinese painting and calligraphy art. Meanwhile, artisans used animal glue in traditional Ukiyo-e woodblock prints in Japan.
In the Middle Ages, the use of animal glue in Europe was widespread in various industries. Bookbinders used it to bind pages to the book’s spine, and carpenters utilized it for joinery and furniture construction. Notably, famous Italian violin makers of the Cremonese school, like Antonio Stradivari and Giuseppe Guarneri, relied on animal glue for their masterpieces, emphasizing its significance in musical instrument construction.
During the Industrial Revolution in the 18th and 19th centuries, the demand for animal glue increased dramatically. Large-scale industries, including furniture manufacturing, bookbinding, and papermaking, all required vast quantities of glue. In response, the first commercial glue factories were established in Holland and the United States, marking the beginning of the modern animal glue industry.
The 20th century saw a decline in the use of animal glue due to the emergence of synthetic adhesives. These synthetic alternatives, like polyvinyl acetate (PVA) and epoxy resins, were cheaper, easier to produce, and had longer shelf lives. However, animal glue remained the adhesive of choice for certain niche industries. For instance, traditional bookbinders, luthiers, and restorers prefer it for its unique properties, such as reversibility and natural composition.
Types of Animal Glue
As you continue to explore animal glue, it’s important to understand each type of animal glue.
Hide glue, gelatin glue, fish glue, rabbit skin glue, and bone glue are all considered types of animal glue.
Each type has its unique properties and uses in various applications, such as woodworking, bookbinding, and instrument making.
Understanding the differences between these types of animal glues will help you make informed decisions on which one to use for your specific project needs.
Hide Glue
You’ll be surprised to learn that hide glue, a type of animal glue, has been used for over 5,000 years and is still preferred by many woodworkers today. This adhesive comes from collagen found in the connective tissues of animals such as cows and horses. The production process involves prolonged boiling of the raw materials until they break down into a gelatinous substance that can be dried and formed into flakes or pearls.
One advantage of hide glue over synthetic glues is its unlimited shelf life when stored dry. Mixed glue can even be reheated for future use. Hide glue also bonds well to itself, making it ideal for furniture repair work.
However, woodworkers need to keep in mind that high humidity can weaken joints made with liquid hide glue, and water-based finishes may soften hide-glue joints.
Finally, different grades of hide glue are available, which offer varying open times during which adjustments can be made before the adhesive sets permanently.
Gelatin Glue
Get ready to be amazed by this natural and eco-friendly adhesive used for thousands of years in cultures around the world. Gelatin glue, also known as collagen glue, is a protein-based adhesive derived from eith recycled pharmaceutical and nutritional gelatin or waste animal remains.
This unique adhesive has several properties, making it an ideal choice for woodworking projects and other applications. It has exceptional, cohesive strength, making it an ideal choice for high-stress applications like wood joinery. Unlike synthetic adhesives, gelatin glue has a longer open time, giving you more time to adjust your workpieces before they stick together permanently.
As a naturally derived adhesive from waste animal remains like bones and hide, gelatin glue is less harmful to the environment than synthetic glue. The manufacturing process for this natural adhesive involves cooking waste animal remains in water to break down the collagen into raw glue. Depending on the application requirements, additional heating or drying can create desired viscosity levels.
With its exceptional strength, longer open time, and natural production process, gelatin glue is quickly becoming popular among woodworkers looking for an eco-friendly alternative to traditional synthetic adhesives.
Fish Glue
Fish glue is a type of adhesive derived from the collagen in fish bones, skin, and scales. It has been used for centuries in various applications due to its unique properties, such as its clear drying characteristics and pliability when set.
Ancient civilizations used fish glue for woodworking, binding, and even creating musical instruments. Fish glue was often used in traditional papermaking and bookbinding in East Asia due to its flexibility and longevity. It also served as an important component in traditional Asian lacquerware, a decorative technique renowned for its high gloss finish and durability.
The process of creating fish glue begins with the extraction of collagen from fish parts. The production of fish glue begins by boiling the parts in water until the collagen breaks down into a gelatinous substance. This substance is then purified, concentrated, and dried, resulting in the final product you can reconstitute with water.
In modern times, fish glue use lessened due to the introduction of synthetic adhesives, which are cheaper, easier to produce, and offer more consistent results.
However, fish glue still holds a niche market in certain industries and crafts. For instance, restorers use fish glue to restore and repair antique furniture and artworks due to its reversibility and natural formulation. Some artists and craftsmen also prefer fish glue for its clear finish and the fact that it doesn’t affect the tone of natural materials like wood, making it popular in some musical instrument construction.
In conservation and restoration, fish glue’s easy removability and non-reactive nature make it a favored choice. As an eco-friendly alternative, it’s also seeing some resurgence in sustainable and traditional crafting communities.
Isinglass
Isinglass, derived from the swim bladders of sturgeon, has a long history of use as a clarifying agent in alcoholic beverages and as a pure form of gelatin in cooking and art conservation.
The primary uses of isinglass have traditionally been in the clarification of beer and wine, where it helps remove suspended particles, and in certain specialty adhesives, such as those used in restoring antique artwork and in bookbinding, where its ability to create a flexible, reversible bond can be advantageous. Medieval illuminators also utilized isinglass to glue gold dust onto manuscripts.
Unlike other types of fish glue, isinglass comes exclusively from the swim bladders of sturgeon, which are particularly rich in collagen. Due to its unique properties, it can be used as an alternative to traditional animal glues in woodwork and restoration projects.
Rabbit Skin Glue
Rabbit-skin glue, a traditional adhesive made from refined rabbit collagen, was commonly used in oil painting to seal canvases and create a smooth surface for fine detailing. This type of animal glue has been used since ancient times due to its fast bonding and low creep properties. However, it’s also known as one of the major causes of cracking in oil paintings.
Despite being replaced by synthetic adhesives in the modern industry, rabbit skin glue remains popular among artists who prefer traditional methods. The preparation involves boiling animal connective tissue, particularly hides in the case of rabbit skin glue, using the correct water-to-glue ratio.
It has been widely used throughout centuries, not only in art but also for other purposes such as wood furnishings and illuminated parchment manuscripts. Artists sand rabbit-skin glue for a flatter texture for finer detail in oil painting. Rabbit skin glue should only be dissolved at 50-60°C, before applying on canvas or other materials. It’s important not to exceed this temperature range as it could denature the proteins in the glue, causing it to lose its adhesive properties.
Bone Glue
If you’re looking for a natural and effective adhesive used for centuries in furniture making and restoration, bone glue is worth considering. Made from animal bones, this type of glue was predominantly used until the middle of the twentieth century and is still popular today due to its safety and environmental friendliness.
Unlike synthetic adhesives, bone glue can be dissolved by applying heat, allowing for easy repairs and corrections.
Creating bone glue involves boiling the animal parts in water until they break down into a gelatinous solution. This solution is then evaporated into a concentrate causing it to gel. The resulting gel is then dried and ground to create the final product. In the nineteenth century, specialized factories were devoted solely to producing animal glues like bone glue.
This traditional adhesive remains an important part of woodworking and restoration projects due to its unique properties and long history of use.
Hoof Glue
Hoof glue is another type of animal glue made primarily from the collagen in the hooves of animals, typically cattle. Like bone glue, hoof glue offers unique flexibility and reversibility, making it a valued adhesive in certain applications.
Historically, the production of hoof glue involved cleaning and boiling animal hooves for extended periods to extract the collagen. This process would break down the collagen into a gelatinous substance, concentrated, dried, and processed into a usable adhesive.
Hoof glue was widely used in a variety of applications, including woodworking, bookbinding, and even in creating decorative glass objects known as “gelatin dioramas” or “Victorian glass pictures”.
Hoof glue was particularly valued for its flexibility, making it a popular choice in manufacturing flexible goods such as leather book bindings and horse-drawn carriages. Its reversibility also made it a preferred adhesive in repairing and restoring antiques, allowing adjustments even after the glue had set.
In modern times, like other animal glues, hoof glue has largely been supplanted by synthetic adhesives. However, it still holds a niche in certain industries. For instance, traditional bookbinders and restorers often prefer hoof glue for its more flexible bond.
Advantages and Disadvantages of Animal Glue
Although synthetic adhesives have largely replaced animal glue, it still holds some advantages over their modern counterparts. One of the biggest advantages of animal glue is that it’s reversible, so if you make a mistake or need to disassemble something you’ve glued together, you can add moisture and heat to break down the bond.
Animal glue forms a strong bond with surfaces, making it a popular choice for artists and craftsmen. However, there are also several disadvantages to using animal glue as well.
- Firstly, prolonged boiling can produce unpleasant odors and fumes because animal glue comes from animal skin and connective tissue.
- Secondly, animal hide glue is sensitive to changes in temperature and humidity, which can cause the bond to weaken or even break over time.
- Finally, while woodworkers may use animal glue as a traditional wood adhesive because of its strength and workability with wood grain patterns, many have moved on from this adhesive due to the disadvantages mentioned above.
How Does Animal Glue Work?
Learning how animal glue works is fascinating, creating strong bonds and bringing art and artifacts to life.
- Animal glues are made through the prolonged boiling of animal connective tissue, which results in a gelatinous substance used as an adhesive.
- The collagen in the animal tissue is broken down into smaller molecules by the heat and water, forming a sticky liquid that can bond with various materials.
- When applied to surfaces, animal glue penetrates the fibers of the material and forms a strong bond as it dries.
- As it cools and dries, animal glue contracts, pulling the two surfaces together and creating a very strong bond.
What Is The Strongest Animal Glue?
The strongest type of animal glue comes from the hides and bones of cattle. This type of adhesive is made by prolonged boiling of connective tissue, resulting in a high-quality protein-based glue that can create an exceptionally strong bond. The hides of animals, particularly cows and rabbits, typically contain more collagen than bones or hooves.
Frequently Asked Questions
What is the process for rendering animal connective tissue to make animal glue?
You’ll need to render connective tissue from animals such as horses, cattle, rabbits or fish to make animal glue. Boil the tissue to create a hydrolyzed collagen solution that for use as an adhesive, coating, sizing, or clarifying agent.
Are there any ethical concerns surrounding the use of animal glue?
You may have ethical concerns about using animal products, including animal glue. While the process of making it involves rendering connective tissue from animals like horses and rabbits, some argue that you should use alternative synthetic adhesives to avoid potential harm to animals.
Can animal glue be used on all types of surfaces or materials?
Use animal glue on materials such as wood, paper, and fabric. However, it will not be suitable for non-porous surfaces or exposure to moisture or high temperatures.
How does the adhesive strength of animal glue compare to synthetic adhesives?
Animal glue has a moderate adhesive strength compared to synthetic adhesives. However, its ability to form strong bonds with porous materials and its reversibility make it useful for restoration work and traditional crafts applications.
Are there any safety precautions to take when using animal glue?
When using animal glue, safety precautions are necessary. It contains organic matter that can attract mold and insects if not stored properly. Wear protective gear since animal glue can cause skin irritation or respiratory problems when exposed to high temperatures during application.
Conclusion
Congratulations! You’ve just learned all about each type of animal glue.
In conclusion, understanding the history, types of animal glues available in the market today, and their respective advantages and disadvantages can help you make an informed decision on choosing an animal adhesive for your specific application needs.
