Finishing materials by applying hot dip treatments
Overview
This standard identifies the competencies you need to carry out hot dipping processes to various substrates, in accordance with approved procedures. You will be required to access the appropriate specifications, to check that these are the current issue and to extract all necessary information in order to carry out the hot dipping operations. You will be required to carry out all necessary preparations to the base materials prior to dipping them and this will include such items as aqueous degreasing, acid cleaning, biological cleaning, mechanical cleaning, rinsing and other appropriate treatments.
The hot dip treatments will include wax coating of steel as a masking material prior to electroplating, coating steel with tin, coating steel with zinc (galvanising) and applying organic coatings for insulation. You will be expected to adjust various parameters to give the desired coating characteristics. You will also need to demonstrate that you can test coatings for compliance to the coating specifications.
Your responsibilities will require you to comply with organisational policy and procedures for the hot dipping activities undertaken and to report any problems with these activities or with the materials and equipment used, that you cannot personally resolve, or are outside your permitted authority, to the relevant people. You will be expected to work with a minimum of supervision, taking personal responsibility for your own actions and for the quality and accuracy of the work that you carry out.
Your underpinning knowledge will provide a good understanding of your work and will provide an informed approach to applying hot dipping procedures. You will understand the dipping procedures used and their application and will know about the base materials, finishing materials and their preparation requirements, in adequate depth to provide a sound basis for carrying out the activities, correcting faults and ensuring the finished components are to the required standards and to the customer's expectations.
You will understand the safety precautions required when carrying out the preparation and hot dipping operations. You will be required to demonstrate safe working practices throughout and will understand the responsibility you owe to yourself and others in the workplace and towards the environment.
Performance criteria
You must be able to:
- work safely at all times, complying with health and safety legislation, regulations, directives and other relevant guidelines
- follow relevant job instructions and specifications
- ensure the material surfaces to be treated are prepared for the finishing operations
- check that the finishing equipment and treatment solutions are set up and maintained at required operating conditions and levels
- carry out finishing according to operating procedures and to meet specifications
- check that the treated workpiece achieves the required characteristics and meets the finishing specifications
- deal promptly and effectively with problems within your control and report those that cannot be solved
- ensure that work records are completed, stored securely and available to others, as per organisational requirements
- leave the work area in a safe condition on completion of the activities, as per organisational and legal requirements
Knowledge and Understanding
You need to know and understand:
- the specific safety precautions to be taken whilst carrying out the activities (including any specific legislation, regulations or codes of practice relating to the activities, equipment or materials)
- the health and safety requirements of the work area and the activities, and the responsibility these requirements place on you
- the hazards associated with the activities, and how to minimise them and reduce risks
- the personal protective equipment and clothing (PPE) to be worn during the activities
- the importance of checking that all substrates and jigs are completely free of water or other solvents prior to hot dipping and the potential consequences of failing to check this
- the advantages and disadvantages of the hot dip coating systems
- the types of specifications that are used during the hot dipping activity and how to check that they are latest issues
- how to assess component suitability for hot dip coating (to include methods of handling, method of pre-treatment, the coating material to be applied)
- the setting up and correct technique for efficient use of the hot dipping equipment (including limitations of geometry of parts for dip coating, operation and locations of emergency stops)
- the selection and setting up for efficient use of the environment (including suction methods for controlling vapours)
- how to clean and prepare the substrates in readiness for the hot dipping process
- methods for jigging, or otherwise holding, components for application of hot dip coatings; the relevance of the jigging material and its compatibility with the hot dip process
- the suitability of the various substrates for hot dipping, and the effects that various elements in the substrates may have on the applied coatings
- properties of the different coating materials and how different characteristics can be imparted to coating materials by the addition of trace materials (for example, the addition of aluminium and nickel to zinc for galvanising)
- how to identify and correct hot dip processing faults and the importance
and control of temperature - how to recognise treatment defects and their prevention and/or correction (including how to remove poorly applied dip coatings without damaging substrates)
- the simple, non-destructive testing procedures to ensure specification compliance
- how to remove poorly applied coatings without damaging substrates
- the cleaning and maintenance procedures of the hot dip processing plant and equipment, including the use of 5S or similar techniques
- the extent of your own responsibility and whom you should report to if you have problems that you cannot resolve
- how to access, use and maintain information to comply with organisational requirements and legislation
Scope/range
Scope Performance
Finish materials by applying hot dip treatments, carrying out all of the following:
- use the correct issue of process and other related specifications
- adhere to health and safety regulations, systems and procedures to realise a safe system of work
- ensure that the equipment is correctly prepared for the hot dip treatment operations
- ensure that any meters and gauges to be used are within their calibration periods
- clean all tools and equipment on completion of the hot dipping activities
- complete the production documentation (such as condition/pre-treatment of substrates, coating material preparation, equipment settings, confirmation of standard of finish)
- leave the work area in a safe and clean condition
Clean and prepare the substrate by carrying out three of the following activities:
- aqueous degreasing
- biological cleaning
- rinsing
- acid pickling
- mechanical cleaning
Carry out one of the following hot dip treatment methods:
- immersion of parts on jigs
- rolling components in coating materials
- immersion of components on hooks
- dip spin coating
- other coating methods
Apply a hot dip coating, using methods and techniques to deal with three of the following issues:
- material type(such as variations in elements that are allowed in the material specification)
- substrate compatibility with the material being applied
variations in porosity - melting point
- geometry
- correct jigging methods
Monitor, measure and (where applicable) correct two of the following hot dip treatment conditions:
- coating thickness
- level of agitation
- spin speeds (where applicable)
- contamination levels
- viscosity
- temperature of coating material
- evaporation rates
- immersion times
- temperature of component
Handle hot treated parts after immersion, using one of the following techniques:
- forced cooling (where applicable)
- rotation of parts during cooling
- water quenching
Apply one of the following types of hot dip coatings:
- molten wax (such as coating of steel as a masking material prior to electroplating)
- molten tin to steel (tinning)
- molten zinc to steel (galvanising)
- organic coatings (such as insulation)
- other specific coating
Carry out three of the following tests:
- thickness of coating
- corrosion testing
- porosity of coating
- surface roughness checks
- abrasion resistance
- appearance of deposits
Check applied coatings comply with one of the following quality and accuracy standards:
- military or aviation standards
- current industry standards and codes of practice
- international standards
- company standards and requirements
- customer standards and requirements