Security seals are a simple way to show whether an adjustment screw, valve, housing or calibrated setting has been disturbed. In production, service and maintenance, lacquer torque-seal products are commonly used as visible tamper indicators, while anaerobic threadlockers provide actual thread locking where resistance to self-loosening is required.
The right choice depends on the component, substrate, temperature, process media, electrical requirements and audit rules. A red lacquer is not automatically suitable for every application.
Key takeaways
- Lacquer security seals are primarily visual indicators of tampering, movement or inspection status.
- Threadlockers and lacquer seals perform different functions: a threadlocker secures the threaded joint, while the lacquer provides a visible reference or tamper mark.
- Fast Dry products are useful where short drying time, anti-sag behaviour and electrical insulation are important.
- Water-based Zero products reduce solvent emissions, but suitability for food-industry applications must always be verified against the exact product documentation and plant requirements.
- Product selection should consider temperature, chemicals, washing, vibration, substrate and application method.
- TAGGR markers complement security seals by providing durable operational markings on difficult surfaces.
What is a security seal and when is it useful?
In an industrial context, a security seal is an element or coating used to make interference with a defined setting or closure visible. Depending on the system, it can:
- show whether a screw, knob, lever or valve has moved,
- leave a visible trace when the setting is disturbed,
- provide identification by colour, code or inspection convention,
- serve as a reference mark for a calibrated or inspected position.
Typical applications include adjustment screws, machine guards, controller housings, valves, fittings, meters and measuring equipment.
Mechanical vs chemical security seals
Mechanical seals
Mechanical systems include plastic pull-tight seals, cable seals and tamper-evident labels. They are most useful when the goal is to control access to a container, door, cabinet or housing.
- Plastic pull-tight seals – disposable and often individually numbered.
- Cable or metal seals – used where higher mechanical resistance is required.
- Tamper-evident labels – used on housings and access covers where removal should leave visible evidence.
Chemical seals – lacquer indicators and threadlockers
Lacquer security seals are applied as a dot or bridge across a screw head, nut or joint. When the relative position changes, the lacquer cracks, separates or becomes misaligned, making the movement visible.
They can therefore be used to:
- indicate unauthorized adjustment,
- show spontaneous movement during inspection,
- mark the approved or calibrated position of a screw or control element,
- provide a visible inspection or process-status mark.
BADER and WIKO lacquer seal families
Standard – general-purpose lacquer security seals
Standard solvent-based lacquer seals are intended for general industrial marking and tamper indication. They provide a clearly visible mark and form a coating that can show movement or interference with the joint.
They are commonly used on screws and adjustment points in machines, electrical cabinets and measuring equipment.
Fast Dry – quick drying and anti-sag behaviour
BADER Fast Dry is designed for applications where short drying time and good behaviour on vertical or overhead surfaces are important. Current Melkib product data for Fast Dry also describes the material as non-conductive and resistant to a range of process media.
For the current 50 ml tube version, Melkib lists an approximate drying time of 1 minute and full cure of approximately 24 hours. Actual drying depends on film thickness and environmental conditions.
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Zero – water-based sealing lacquers
The Zero series uses a water-based formulation without organic solvents. It is intended for applications where reduced solvent emissions and lower odour are important.
For food, pharmaceutical or packaging environments, do not rely only on the name “Zero” or a general marketing statement. Verify the exact product documentation, intended contact scenario and internal requirements such as HACCP, IFS or BRC before use.
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Secure and Topsecure
Secure and Topsecure variants are intended for applications with a higher requirement for tamper indication and resistance to attempted removal. They are relevant where unauthorized adjustment must remain clearly detectable during inspections or audits.
WIKO lacquers for thread and position marking
WIKO marking lacquers are used to create a visible reference mark across screws, nuts and joints. Their main function is to show movement or interference and to document the approved position.
They should not be treated as substitutes for anti-corrosion coatings or dedicated threadlocking adhesives unless the exact product documentation states otherwise.
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Anaerobic threadlockers as a complementary solution
Where the joint must resist self-loosening under vibration or dynamic load, anaerobic threadlockers such as selected LOCTITE products may be appropriate. They lock the threaded connection itself rather than merely providing a visual mark.
In demanding applications, a threadlocker and a visible lacquer mark can be used together: one provides mechanical locking, while the other provides a quick visual inspection reference.
When should you choose lacquer, mechanical seals or threadlocker?
| Solution | Main function | Typical application |
|---|---|---|
| Mechanical seal | Shows whether access has been opened or the seal physically broken. | Doors, cabinets, containers, transport packaging. |
| Lacquer security seal | Shows movement, adjustment or tampering at a specific point. | Screws, valves, adjustment points, electronics. |
| Anaerobic threadlocker | Mechanically secures threaded fasteners against loosening. | Threaded joints exposed to vibration or dynamic load. |
| Industrial marker | Creates a durable operational or identification mark. | Machine numbers, arrows, service marks, process identification. |
How to choose the right security seal
1. Define what you are sealing
- an adjustment screw, nut or retaining ring,
- a valve, fitting, meter or sensor,
- a cover, service access point or housing,
- an electronic device or control module.
2. Check the operating conditions
Consider:
- temperature – including both application temperature and later service temperature,
- process media – oils, fuels, coolants, cleaners and solvents,
- washing and humidity – including CIP or pressure washing where applicable,
- vibration – if the joint itself must be secured, consider a suitable threadlocker in addition to the visible lacquer mark.
3. Check electrical and hygiene requirements
For electrical and electronic applications, confirm that the product is non-conductive and suitable for the component and environment.
For food, pharmaceutical or cosmetic production, check the exact regulatory and plant requirements. A water-based formulation by itself does not prove suitability for every food-contact scenario.
4. Choose the package and application method
Lacquer seals are available in different formats for service work, manual production and automated dispensing. Selection should consider the number of application points, required bead size, workstation ergonomics and the available dispensing equipment.
5. Prepare the surface correctly
- remove loose contamination and old coating fragments,
- degrease the intended application point using a compatible cleaner,
- allow the surface to dry completely before applying the seal.
Poor surface preparation can make even a correctly selected product an unreliable tamper indicator.
Common mistakes when using lacquer security seals
- Applying to a greasy surface – reduces adhesion and can cause the mark to detach without a meaningful tamper trace.
- Applying an excessively thick layer – can extend drying time and alter cracking behaviour.
- Ignoring temperature and chemical exposure – can cause softening, discolouration or loss of adhesion.
- Assuming every lacquer is non-conductive – always confirm the exact product properties.
- No process documentation – makes it difficult to determine what product, colour and inspection standard were used.
Security seals in practice
- Machines and production lines – adjustment screws, stops, valves and pressure settings.
- Electronics and automation – potentiometers, switches, connectors and control modules where a non-conductive product is required.
- Food and pharmaceutical production – selected water-based sealing products where the exact documentation and plant requirements permit their use.
See lacquer security seals in use
This Melkib video shows practical differences between selected Standard, Zero and Fast Dry security-seal products and demonstrates typical application methods.
TAGGR industrial markers – a complement to security seals
TAGGR industrial markers are not security seals in the strict sense because they do not lock a threaded joint or create a dedicated tamper-evident bridge. They are useful as a complementary marking system for machine settings, service points, flow directions and identification.
What surfaces can TAGGR Rough Surface Markers be used on?
According to the current manufacturer and Melkib descriptions, TAGGR Rough Surface Markers are intended for difficult industrial marking conditions, including:
- smooth and rough metals,
- greasy, oily and dirty surfaces,
- wet surfaces and selected underwater marking applications,
- concrete, stone, rust, wood, plastics, glass and neoprene.
Key properties of TAGGR markers
- high-covering permanent lacquer,
- weather resistance referenced to DIN EN ISO 2810 in manufacturer information,
- wide temperature capability depending on colour and product variant,
- resistance to selected media according to the product documentation,
- electrically insulating lacquer system where confirmed for the exact variant,
- steel-ball writing head designed for difficult industrial surfaces.
Marker or security seal?
Use a lacquer security seal or threadlocking system when the goal is to detect unauthorized adjustment or secure a threaded joint. Use a TAGGR marker when you need a durable operational marking on a difficult surface.
FAQ – security seals
Does a lacquer security seal prevent a screw from loosening?
Its primary purpose is to indicate movement or tampering. If mechanical resistance to self-loosening is required, use a suitable threadlocker or another fastening method specified for the joint.
How should I choose the seal colour?
Choose a colour that is clearly visible against the substrate and consistent with the plant's inspection standard. Different colours can also be assigned to shifts, process stages or inspection periods.
Are Zero seals automatically food safe?
No universal statement should be made for every application. Their water-based formulation reduces solvent emissions, but suitability must be verified against the exact product documentation, the location of use and the plant's food-safety requirements.
Can a lacquer seal be removed and reapplied without leaving evidence?
A correctly selected and applied tamper-indicating lacquer should make movement or removal visible. The exact failure pattern depends on the product, substrate and application thickness.
How long does a Fast Dry seal take to dry?
For the current BADER Fast Dry 50 ml tube product, Melkib lists an approximate drying time of 1 minute and full cure of approximately 24 hours. Actual times depend on film thickness and environmental conditions, so verify the current TDS and validate the process.
Can I combine lacquer seal with a threadlocker?
Yes. This is often useful where the threadlocker secures the joint mechanically and the lacquer provides a visible inspection or tamper mark.
Summary
Security seals should be selected by function, not colour alone. Mechanical seals control access, lacquer products provide visible evidence of movement or tampering, anaerobic threadlockers secure threaded joints, and industrial markers provide durable operational identification.
For a reliable process, verify temperature, media exposure, electrical requirements, substrate, surface preparation and the exact technical documentation for the selected product.
Need help selecting a security seal?
Send us information about the component, substrate, operating temperature, process media and whether you need tamper indication, thread locking or only a durable marking. This makes it possible to choose the correct solution rather than relying on colour alone.
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