Curing Anaerobic Adhesive
Consistently Curing Anaerobic Adhesives
Anaerobic Adhesives (AAs) are often identified by the job they perform; threadlocking, thread sealing, retaining compounds, & gasket makers. They cure only in the absence of oxygen and presence of metal. Similar to cyanoacrylates (instant adhesives) there is a maximum gap that anaerobic adhesives will cure through. Controlling that gap is critical to achieving full anaerobic curing. The speed of the cure is related, not only to the gap, but also the reactivity of metals being used. For example brass is more reactive than steel which is more reactive than anodized aluminum.
For Consistent Anaerobic Curing:
- Maintain a consistent gap between the parts
- Ensure that components are consistently reactive – for example zinc plated finishes can vary batch to batch – the differences in cure speed are small but can be detected.
- Temperature also plays a role. This can be significant as many of these products are used in heavy equipment which is often assembled or repaired in all weather.
The following shows typical cure times for an anaerobic threadlocker at 23°C. Note copper will follow the faster cure curve where passivated surfaces like stainless steel will be closer toward the slower cure curve. Lower temperature and larger gaps will reduce anaerobic curing speed.
Accelerate Anaerobic Curing
Surface conditioners can be used to activate inactive surfaces to allow or accelerate the cure. Parts can be activated with ASC10 up to 30 days prior to applying the anaerobic adhesive or sealant.