QA Inspection Service

If we are not the contractor, we can offer an independent inspection service.  If we are the contractor, our internal quality control is to the same high standards.

On arrival at the site the Inspector will establish lines of communication with the Client, the Contractor and with teh company Inspection Services Head Office for the submission of reports and routine records.

The Inspector’s first objective is to ensure that the equipment to be used is in working order and is in accordance with the Client’s and the Paint Manufacturers specification. If necessary he will advise on modification, alteration or repair of any defective equipment and the purchasing of any replacement items.

Prior to blast cleaning, the Inspector will examine the initial preparation of the steel to check for weld spatter in the case of prefabricated sections and will ensure that all sharp corners and edges have been rounded off. Any laminations which are obvious at this stage will be brought to the attention of the Site Engineer or Steel Superintendent for his consideration.

After the blast cleaning has commenced, the Coating Inspector will make regular examinations of all blast cleaned steel to assess whether the standard of cleanliness required in the specification is being obtained, and to ensure that the maximum cleaning rate and efficiency is being achieved - but he will not cause undue delays by doing so. Once the job is progressing smoothly and an efficient work method has been established, the Coating Inspector will examine cleaned surfaces whenever the blasting foreman feels that the overall condition of the steel section being blasted will be of a standard acceptable to the Inspector.

In polluted industrial environments checks for soluble iron in the forms of chloride or sulphate can be carried out to assess the degree of steel contamination. Similarly, copper sulphide tests can be carried out to determine trace quantities of millscale remaining on the surface of new steel after blast cleaning.

Before application of the coating, the Inspector must verify that the climatic conditions are within the specified limit.

This is carried out using properly calibrated electronic or traditional instrumentation to determine substrate temperature and relative humidity / dew point.

Relative Humidity:
This figure is obtained by means of a Whirling or digital Hygrometer and is converted into Dew Point.

Steel Temperature:
This is measured by a magnetic adhering thermometer in ° C.

We Inspection Services have supervised and inspected many projects utilising the new generation of surface tolerant coatings. We are therefore very experienced in assessment of the lower grades of preparation that can be allowed for atmospheric exposure conditions.

We also liase with the coating manufacturers on behalf of our clients, to enable optimum use and performance from the specialised systems available.

No painting will take place if the Steel Temperature is equal to or less than the Dew Point because when the Steel Temperature is less than the Dew Point water vapour condenses on the Steel Surface. Ideally, the cleaned steel should be coated immediately after blast cleaning and the Coating Inspector must strike a fine balance between producing too much cleaned steel and too little. Too little could result in not meeting target dates, on the other hand too much could mean that all the coating could not be applied before the steel had ‘turned’, resulting in the need for reblasting which could cause even more delay.

The problems of application and spray techniques should have been solved during the ‘dummy run’, (see Initial Appraisal) but the Inspector should observe the first few spray passes and correct any faults in application. When the spray operator has mastered the application he will be allowed to operate without direct supervision, the Coating Inspector making visual inspections and taking wet film thickness measurements from time to time.

When sufficient area has been covered to make the calculations significant the Inspector will estimate spreading rate, paint consumption and the quantity of material required to finish the job. He will indicate ‘holidays’ and areas of too thin coating and ask for these defects to be made good.

The drying and curing times will be checked by the Inspector using the ‘solvent rag test’ as a guide where applicable, and he will ensure that the inter-coat time intervals are observed and that the surface is in a condition to receive the subsequent coats of the paint system. Contamination of paintwork by oil, dust and moisture between coats must be avoided at all costs.

Shop-primed prefabricated steel sections, blast cleaned automatically or manually and coated with wash-type primers, red oxide epoxies and zinc epoxies, pose their own specialised problems in the application of subsequent coating systems. We will advise on the preparation of weathered shop-primed steel, which has accumulated rust from damage caused by fairing, welding and physical damage sustained during storage and transportation.

During mixing and spraying operations the Inspector will ensure that fire safety precautions are observed and that there will be no build up of inflammable vapours in enclosed spaces.

When the coating has dried or fully cured the Dry Film Thickness will be measured and, where specified, the incidence of ‘holidays’ in the coating and its adhesion to the steelwork will be measured by using an Elcometer Adhesion tester or cross hatch test.

The Inspector will decide when a section of coated steel has cured sufficiently to be handled without causing damage to the coating and will ensure that when it is handled great care it taken to prevent damage.

The work of actual inspection finishes at this point and is followed by the equally important phase of report writing and documentation.