Anaerobic adhesives are single component, solvent-free adhesives that cure in the absence of air and in the presence with metal ions. Anaerobic adhesives stay liquid until isolated from oxygen in the presence of metal ions, such as iron or steel. For instance, as soon as an anaerobic adhesive is sealed between a nut and a bolt on a threaded assembly, it quickly “cures” or hardens to form a tough cross-linked plastic. The liquid adhesives are designed for use in challenging applications to fill the spaces and surface irregularities between tightly mated thread or cylindrical parts thus eliminating the need for washers and gaskets.
Anaerobic adhesives are intended for metal-to-metal assemblies though they can be used with other materials as well from time to time. Due to the presence of metal ions, it speeds up the cure of these products. Upon assembling parts with the use of these adhesives and you have excessive liquid squeeze out; it will not set because of the air exposure. To remedy this, basically wipe up the excess away with a common solvent such as acetone or isopropyl alcohol.
Basic Use of Anaerobic Adhesives
One of the best characteristic of anaerobic adhesive is that it cures rapidly. Basically, the bonded parts are fixed in less than 10 minutes depending on the grade of the adhesive. Most of the time, it takes 24 hours to completely cure the joined parts. If there is a need to accelerate the curing time of threadlocking adhesive, you can do so by simply applying heat. On average you can heat cure these products at 250°F (121°C) for approximately an hour or at 150°F (65°C) for more or less three hours. Doing this acceleration process will result to reduced ultimate strength. This is because whenever you speed up the cross-linking of the polymer, its ultimate strength eventually decreases. Knowing this information is critical in order for you to assess whether it is suitable for your application to speed it up.
The following are some of the valuable uses of anaerobic adhesives:
- Augments the seal or holding force of a mechanically connected assembly
- Threadlockers – An anaerobic adhesive prevents corrosion and loosening of the fastener.
- Thread sealants
- Retaining materials – An anaerobic adhesive allows bonding or joining together parts that were previously only possible with the use of press fits.
- Pipe sealants
- Gasketing – improves load transfer and stress distribution across flanges.
Advantages of Using Anaerobic Adhesives
With all the uses of an anaerobic adhesive, here are lists of benefits you can get in using it.
- Stability and consistency of performance to meet the needs of nearly all gasketing, threadsealing, threadlocking, pipe-sealing, and retaining applications.
- Distinctive chemistry that more often than not gets rid of the need for priming inactive metals.
- Improved product reliability
- Superior production output
- Lighter weight assemblies
- Enhanced finished product quality
- Quicker cure times
- Dependable on active or inactive surfaces
- Easy to apply
- Supports a more reliable finished product
- Removes corrosion
- Eradicates vibration loosening
- Reduces fastener fatigue
- Eliminates other mechanical locking devices
- Allows for relaxed machining tolerances
- Reduces cost