Loctite is relied upon every day for its incredible strength and durability. Rapid is proud to be able to supply customers directly with a comprehensive range of Loctite products, so that you are never stuck for a solution.
Harnessing this super strength adhesive for your everyday applications is the key to the appeal of Loctite. Superior bond strength, long life and flexibility are just some of the characteristics that go into making Loctite adhesive such an effective way to bond, seal, retain and secure.
Why do people love Loctite? Is it because the same type of threadlocking adhesive you might use around your workshop also secures the bolts of the gigantic boring machines that have dug the Crossrail tunnels deep beneath London? Or that just three grams of structural bonding adhesive is enough to pull a freight train with a combined weight of 208 tons?
Rapid has developed a very close bond with Loctite. We are delighted to offer customers a comprehensive service, supplying a range of products that meet all of your adhesive, sealant, cleaning and degreasing requirements. We have the product knowledge and the technical expertise to fully support you.
Threadlocking
It was in 1953 that Vernon K. Krieble invented anaerobic threadlocking – an adhesive that only cures in the absence of air – and in so doing the Loctite story began to flow. Krieble’s discovery was regarded as so pivotal that the Loctite brand was created to promote and sell his invention (the name itself came from Krieble’s daughter-in-law). Loctite and threadlocking are bound together like nut and bolt – and remain the go-to brand for threadlocking adhesive.
How Loctite Keeps Assemblies Secure
Self-loosening of metal screw joint bolts is one of the key reasons mechanical assemblies fail.
In certain applications, such as automotive, this is an outcome which could lead to catastrophic equipment failure and potential loss of human life. Any number of factors can contribute to a loss of bolt tension – changes in temperature, poorly fitting parts, vibration or insufficient clamp loads. These load changes produce short-term frictionless situations where the bolt unwinds from the nut and eventually leads to a relaxation of tension in the threaded assembly.
Finding a solution to this issue is what drove the founder of Loctite, Vernon K. Krieble, to experiment with chemical threadlocking adhesives. He patented a threadlocking fluid technology which cured only in the absence of air – in other words, when the fastener is applied and maximum torque is attained. The anaerobic adhesive acts like a lock, filling every available space between the thread and the nut.
Chemical threadlocking adhesives can also be epoxy-based, characterised by extremely strong bonds and resistance to heat and chemicals, but they need to be mixed with a hardener in order to cure. Mechanical threadlockers such as nylon increase friction between the mating threads, and require a higher installation torque, but generally are only about 50% as strong as chemical threadlocking products. Other common thread treatments include thread sealants and anti-seize compounds.
Even if removal of the part is required during its lifetime, a chemical threadlocker could still be used, such as Loctite 222. The incredible spectrum of applications in which Loctite threadlocking adhesive is employed underlines its universal appeal and the degree to which the brand is seen as the definitive threadlocking solution.
Structural Bonding Adhesive
Rapid stocks a comprehensive range of epoxy and acrylic-based Loctite adhesives to meet all the demands of industrial bonding, sealing and assembly.
Some surfaces are more difficult to bond, or are used in environments with specific challenges or operational requirements (such as food preparation). Structural bonding adhesives are also ideal for bonding combinations of substrates, such as metal to plastics, metal to glass and metal to wood. Epoxy adhesives provide rigid bonding for small to medium surfaces, while acrylic structural bonders offer a solution for rigid to slightly flexible bonding of small surfaces.
How to Apply your Adhesive
Applying your Loctite adhesive correctly is vital to achieving an effective bond or seal. Check you are doing things right below.
Threadlocking
Through hole
- Assemble bolt first, then apply threadlocker
Blind hole
- Apply onto lower third of bolt
- Add a few drops into the blind hole
- Get even threadlocker distribution when assembly is screwed together
Post assembly
- Assemble nut and bolt and dispense product at the edge of nut and bolt
If several bolts are being tightened, torque them down to the correct value within the fixture time of the product or use a slow curing product.
Thread Sealants
- Apply a 360° bead to the leading male thread, leaving the first thread free
- For bigger threads, apply both on male and female threads
- If using Loctite 55, wind the cord onto the pipe thread in the same direction as the thread, starting from the end of the pipe. For optimised performance, apply in a criss-cross pattern
Gasketing
- Apply as a continuous closed bead onto one flange surface. Place the bead close to the inner rim of the flange and encircle all holes. Small scratches can be filled by the adhesive
- Loctite 510 and Loctite 518 can also be applied by roller onto large flanges
- Assemble flanges and tighten bolts immediately
Retaining
For slip fitted assemblies
- Apply adhesive around the leading edge of the male component and inside the female component. Use rotating motion during assembly to ensure good coverage
- Recommended products: Loctite 603, 638, 660
For press fitted assemblies
- Apply adhesive thoroughly to both bond surfaces. Assemble at high press on rates.
- Recommended products: Loctite 603
For shrink-fitted assemblies
- Apply adhesive onto the shaft, heat the collar to create sufficient clearance for free assembly
Instant Adhesives
- Apply adhesive by drop or bead to one of the bond surfaces (not to surfaces on which activator has been applied)
- Assemble the parts immediately. Bond should be held or clamped until the adhesive has fixtured
Structural Bonding
Acrylics & Epoxies
- Before mounting the static mixer onto the cartridge, push out a small amount of product to equalise pistons
- Mount static mixer and push some product out until a uniform colour is achieved
- Directly after mixing, apply an even coverage of adhesive to the bonding area
- After use, leave the static mixer in place and use it as a cap
- Joint should be allowed to develop full strength before being subjected to any service loads
Metal-filled Compounds
For applying Loctite 3471 & 3475
- Apply adhesive to the working area with the spatula provided
- Prevent the repaired parts from moving during cure
- Full cure achieved at room temperature after 72 hours
Sealants
Loctite's sealants meet the diverse needs of production environments and commercial industries. See below for Rapid's range of silicone, gasketing, pipe and thread sealants for high quality bonding and sealing.
Cleaners & Degreasers
Substrates need to be free of contaminants to get the best results from your Loctite adhesive. Using cleaning and degreasing solutions, activators and primers will ensure the best possible surface for working.
Lubricants
Loctite anti-seize and silicone grease provide exceptional lubrication performance for a wide range of plastics and metals, including stainless steel, copper, brass and aluminium.
Equipment, Systems & Solutions
At a certain scale, dispensing adhesive has to be integrated within fully automated factory procedures. This results in improved process efficiencies, minimal material waste and reduced manufacturing costs.
Loctite has developed a comprehensive range of industrial equipment solutions, from UV curing equipment and volumetric dispensing to dispense reservoirs and robotic systems.
Controllers, Reservoirs & Dispense Valves
Loctite’s dispensing units include controllers and reservoirs combined into single units, with digital timing control for up to two automatic dispense valves. The integrated dispense reservoirs are suitable for all single component Loctite adhesives up to 80,000 cPs. Multi-function controllers featuring digital timing and programmable logic control for up to three independent pneumatic or electric functions, allowing for storage of up to ten programs. Single function controllers provides control for the manual and timed opening and closing of dispense valves.
Volumetric Dispensing Systems
Volumetric dispensing systems control the dispensing of adhesive by cartridge, syringe and bottle. Posi-Link Actuators effect incremental movements of a piston and displace programmable quantities of adhesive. The volumetric dispensing systems also include a peristaltic dispenser for applications that require a specific flow rate, as well as single and dual rotor volumetric displacement devices for precise applications from product reservoirs. The single and dual rotor equipment can apply Loctite products such as 2-part MMAs, epoxies, polyurethanes, silicones, anaerobics and acrylates with a high precision level.
Robotic Systems
From benchtop to gantry operation, Loctite offers a range of solutions to allow manufacturers to reliably dispense patterns of liquid material on a programmed basis. Benchtop robots are designed specifically for precision dispensing of adhesive and sealants onto complex surface configurations. Gantry robots include a custom gantry design configuration that make them ideal for integrating with automatic transfer lines and conveyors. The SCARA robot provides maximum flexibility for complex dispensing applications, with a multi-jointed arm that moves above the work surface. The Rotary Dispensing system is designed to control a syringe system, cartridge or dispense valve for dispensing adhesive in a circular pattern.
Light Curing Systems
Specifically designed for UV adhesive, Loctite’s UV curing equipment includes spot wand units, flood units, chambers, conveyors and light meters designed for use in a wide variety of bonding, potting, tacking and sealing applications. Single and quad spot controllers can be operated in continuous or programmed light output modes; flood light units are available in bench top and hand held models; chamber and conveyor units operate by mounting the adhesive assembly into enclosed areas and conveyor belts; while light meters detect major malfunctions as they occur in the dispensing process.
View Loctite’s brochure for more information about any of these products
Importance of surface preparation
Buying that premium tube of threadlocking adhesive is no guarantee of achieving an unbreakable bond. Before adhesive is even applied proper surface preparation should take place. Unless surfaces are free of contaminants like rust, water, oil, dirt and dust, the quality and lifetime of the bonding joint will be adversely affected.
It all comes down to something called ‘surface energy’. Ensuring that your substrate has a higher surface energy than the adhesive you are applying will create a better bond. Dirt and other contaminants reduce the surface energy of the substrate, so using cleaners and degreasers is an effective way to increase the strength of your bond.
1. Imagine water on the bonnet of a car
A good example to use to explain the concept of surface energy is that of a waxed car bonnet. A bonnet that has been waxed after washing has lower surface energy than water, so water just rolls off the bonnet surface like a ball. This is called ‘minimal wetting’. A car that has not been waxed has much less friction and higher surface energy, so that when it comes into contact with the water, the water spreads out and fills the contact area.
The objective of surface preparation is to increase the wetting process and give your adhesive a greater area in which to expand into.
2. Cleaning & degreasing the substrate
While it might look clean enough with the naked eye, your substrate can hold contaminants from machining, handling, protecting, manufacturing and facility surroundings. It is estimated that even a thin film of oil will reduce adhesive performance by as much as 60%. Applying a cleaner, isopropyl alcohol or a degreasing solvent such as Loctite 7063 will remove dirt and debris. It may be necessary to immerse the substrate in a fresh bath of solvent, rinsing and then drying before applying the adhesive.
3. Roughing up the substrate
We all know that we should sand a surface before painting it. The same applies to adhesion and surface preparation. Giving the substrate a rough abrasive workover with sandpaper or a wire brush will remove heavy deposits as well as creating a surface area with greater peaks and valleys, which has the effect of giving the adhesive more to grip to and increasing adhesive properties. Degreasing should take place before and after the abrasion process.
4. Applying a primer
Once the part is clean, dry and rough, it might still have a low surface energy. Some materials are notoriously hard to bond, like polyethylene, polypropylene, polytetrafluoroethylene (PTFE) and thermoplastic rubber materials. If that is the case, applying a polyolefin primer such as Loctite 770 can increase the surface energy of these substrates so adhesives bond more effectively. Apply by spraying, brushing or dipping at ambient temperature.
