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How To Apply Loctite Threadlockers

For over 60 years, Loctite have been producing a variety of threadlockers suitable for a wide range of applications. These so called “red bottle” products can be applied in place of conventional fastening methods and help to prevent loosening of threaded assemblies, which in turn can lead to serious accidents and a total shutdown of a production plant.

But once you have selected the right threadlocker, you need to apply it in the proper way to achieve all of the benefits.


Surface Preparation

Correct surface preparation is key before any bonding application, and the use of threadlockers is no different.

Loctite recommend the use of Loctite SF 7063 to degrease and clean the threaded components prior to application.

Loctite SF 7063 is a general-purpose product for cleaning and degreasing any kind of surface or machinery component before proceeding with a repair or assembly job involving Loctite adhesives. It is a solvent-based cleaner and the product leaves no residue. Loctite 7063 removes most greases, oils, lubrication fluids and metal cuttings.

All components should be dried before application of the adhesive.

"Did you know that correct cleaning can improve the grip (adhesion) of the threadlocker by as much as 60%?"

 

Activation

If you are applying a Loctite threadlocker where cure speed is unacceptably long, or large gaps are present, it is recommended that an activator is used. Two products are available:

  • Loctite SF 7649 – A solvent based activator designed to promote the curing speed of Loctite anaerobic adhesives and sealants without any significant loss of joint strength. It is especially recommended for applications with passive metals or inert surfaces and with large bond gaps.
  • Loctite SF 7240 – A solvent free activator designed to promote the curing speed of Loctite anaerobic adhesives and sealants without any significant loss of joint strength. It is especially recommended for applications where the cure conditions are under 5°C.

Application

To aid in the application of Loctite threadlockers, a range of dispensing equipment is available. This includes the Loctite Pro Pump Handheld Dispenser, suitable for both 50ml and 250ml sized bottles as well as dispensing needles in a variety of gauges that can be applied onto the dispenser or directly onto the bottles themselves.

For more information on the Loctite dispensing range, read our Loctite Application Equipment guide.

For blind hole applications, drops of liquid threadlocker should be applied down the female threads into the bottom third of the hole and the bottom of the hole. To ensure complete coverage, it is suggested that threadlocker also be applied to the threads where they are engaged.


Curing

The rate of cure of a specific Loctite threadlocker will depend on a variety of factors:

  • Use of an activator to aid the cure
  • Temperature conditions of the cure
  • The product itself – different products have different cure times
  • The substrate the threadlocker is being applied to

Please Note: for locking plastic fasteners, Loctite recommend the use of Loctite instant adhesives.