Fish glue
Fish glue
EXPERT KNOWLEDGE FISH GLUES
Production and properties of fish glues
Fish glues are produced from the swim bladders and other collagen-rich components of fish. Similar to other glutin glues, the collagen is converted into glutin, which gives the glue its adhesive strength. One major difference to Bone glues is that Fish glues are often used as cold glues and do not necessarily have to be heated.
It is usually sold in liquid or granulated Shape. The liquid version is ready to use immediately and is therefore particularly convenient for smaller repairs or delicate work. Granulate, on the other hand, is prepared by soaking in cold water and then heating in a water bath.
Difference to Bone glues
The main difference between Fish glues and Bone glues lies in their consistency and use. While Bone glues shape a hardness to glass-hard bond, Fish glues remain elastic, making them ideal for bonds that need to tolerate slight movement.
Fish glues:
- Available in liquid and ready-to-use form
- Shapes elastic bonds
- Can be processed cold
Bone glues:
- Must be heated
- Dries as hard as glass
- Particularly suitable for use where maximum strength is required
Areas of application for fish glues
Thanks to its elasticity and versatility, Fish glues are a popular adhesive for numerous ranges of application:
- Wood joints: Ideal for restorations and intricate woodwork, as it combines well with other materials.
- Papers and bookbinding: Its elasticity makes it perfect for papers, as these expand and contract when exposed to moisture.
- Ceramics: Fish glues also adhere to smooth surfaces and provide a strong but flexible bond.
- Restoration: Like other glutin glues, fish glues are reversible, making them particularly easy to repair.
Processing fish glues
Fish glues are particularly easy to work with as they are often supplied already liquid and ready to use. The rules for working with granules are similar to those for bone glues:
- Preparation: the granules are pre-soaked in cold water until they have reached a gel-like consistency.
- Heating: The glue is then heated in a water bath to the desired temperature (approx. 60-70 °C). It is important not to use metal such as iron rods for stirring, as this can impair the adhesive strength.
- Use: The glue is applied evenly to the surfaces to be joined. Excess glue can be removed with a damp cloth.
Liquid Fish glues can be applied directly without prior heating or mixing.
Tips for shelf life: To prevent mould from forming on unused glue residues, a few drops of citric acid can be added. Alternatively, the glue can be stored in the fridge.
Advantages of Fish glues
Fish glues offer numerous advantages that set them apart from synthetic adhesives:
- Ease of repair: its solubility in water means it can be removed or renewed at any time.
- Resistance to ageing: Fish glues are durable and remain stable for years.
- Environmentally friendly: As a natural glutinous glue, Fish glues are biodegradable and free from synthetic additives.
- Can be painted over: Unlike many synthetic glues, cured Fish glues can be painted or stained over without any problems.
Disadvantages and restrictions
Despite its many advantages, fish glues also have some weaknesses:
- Water sensitivity: Fish glues are not waterproof and are therefore only suitable for indoor uses.
- Limited strength: Compared to bone glues, the adhesive strength is somewhat lower, which makes it less suitable for highly stressed joints.
- Storage: Liquid Fish glues have a limited shelf life and must be stored in a cool place to prevent mould growth.
In our range you will find Isinglass glues granules and liquid Fish glues, two high-quality glutinous glues of animal origin, which are obtained from fish raw materials such as swim bladders or skin. Both glues are characterised by special properties that make them ideal for different uses.
Isinglass glues are produced from the swim bladders of sturgeon fish and offer a particularly pure and high-quality form of glutinous glue. It is available in granulate or sheet form and is known for its high adhesive strength and transparency. Before use, the granules must be soaked in water and then heated to around 60-70 °C in a water bath. However, this complex preparation allows the viscosity and strength to be customised, making it ideal for restoration work, musical instrument making or delicate tasks such as bonding paper and parchment. The joints are glass-hard, less elastic and dry quickly on cooling, which makes it ideal for static bonding.
In contrast, liquid Canadian Fish glues are ready to use and can be applied directly without heating. It is made from a mixture of collagen-containing fish components and is ideal for minor repairs and restorations thanks to its uncomplicated handling. Its elastic dry structure allows easy movement, which is why it is often used when working with delicate materials such as wood, ceramics, paper or leather. Due to its flexibility, it is ideal for uses such as bookbinding or furniture repairs where a certain pliability of the joints is desired.
In terms of adhesive strength, Isinglass glues outperform liquid Fish glues as they produce extremely strong and durable bonds. In comparison, liquid Fish glues offer a slightly lower but still robust adhesive strength and score points for their adaptability to flexible joints.
There are also differences in storage: Isinglass glues granules have an almost unlimited shelf life when dry, but must be used within a few days of mixing as they quickly go mouldy. Liquid fish glues, on the other hand, should be stored in a cool place and have a limited shelf life due to their ready-to-use consistency, which can be extended with preservatives.
