Inspector’s Responsibilities Regarding Coating Materials

9.5.6 Inspector’s Responsibilities Regarding Coating Materials

Make sure that the coatings and allowable thinners used are those specified. Know where the coatings are stored on site. Ensure storage conditions are in accordance with specifications and the manufacturer’s latest instructions. Check containers for any sign of damage.

Know how the coatings are to be mixed, thinned, and agitated, and then ensure that this happens. Be sure all pigments are worked into the liquid coating. If the coating is a two-pack or three-pack product, be sure the correct components are stirred properly, combined as specified and then mixed thor- oughly. Make sure the workers observe manufacturer’s recommended pot life and induction or sweat-in times. Know the vol- ume of solids, wet-film and dry-film thick- nesses specified and allowable tolerances, dry, and re-coat times, and times for proper cure.

Figure 9.6 Coating Materials in Packaging

9.5.6.1 Sampling Coatings

The specification may require the contractor or inspector to take samples of the coatings on the project, spelling out the sampling pro- cedure, number of samples taken, labeling procedures, and storage requirements, etc.

The sampler should use only clean contain- ers when taking partial samples to avoid contaminating the sample. Samples may be partial 0.5 pint to 1 qt. (250 mLto 1 L) or unopened containers, 1 to 5 gals (5 to 20 L). The inspector may be required to visit the manufacturer’s plant to take samples of the coating.

Inspector’s Responsibilities Regarding Sampling Coatings

Alternatively, the coating specification may require the inspector to take samples of the coating materials on site. The inspector should follow the specification carefully, as well as the following:

• Select coatings to be sampled at random • Ensure coatings are thoroughly mixed • Place the amount specified in the correct

container • Label the sample container with the fol-

lowing data:

— Product name and number

9-14 Coating Project Specification

— Color — Batch number — Date the sample was taken — Inspector’s name

The inspector should ensure that each sam- ple container is correctly sealed and is stored under safe and appropriate conditions. To avoid sampling error, some clients prefer that an unopened coating container be sent to the testing lab, where the material can be mixed and sampled under more controlled

Figure 9.7 Proper Application of the Specified

conditions.

Coating is Critical to it’s Performance and life Cycle

9.5.7 Inspector’s Responsibilities Regarding Workmanship

9.5.8 Inspector’s Responsibilities

Inspectors must understand the nature of the

Regarding Application

work to be done. Have a copy of the manu- Ensure that the coating application is done facturer’s latest instructions and understand

as specified (in a proper “workmanlike” them thoroughly. At the pre-job conference,

manner) and is free from defects. Know ensure that workmanship performance

exactly what thickness tolerances are expectations are clearly understood by all

allowed. A good specification states a mini- participants.

mum and a maximum DFT for each coat and for the total system: for example, 4–6 mils

Observe the workers and report any unac- (100–150 µm) per coat and 12–18 mils ceptable work to the supervisor, the owner’s (300–450 µm) for the total system. If this is representative, or to the contractor for cor- not the case, then insist in the pre-job con- rection ( Figure 9.7 ). Stay safe. You are ference that clear, practical DFT standards responsible for your own safety and for per-

be established, understood, and agreed upon sonally following all safety requirements

by all parties.

established for the job. Report any question- able conditions or practices to the safety

It is important to understand that the inspec- engineer immediately.

tor’s responsibility is to ensure the specified DFT range is achieved ( Figure 9.8 ). It is a disservice to both the client and the contrac- tor if an inspector insists on an extra topcoat just to make sure that any thin spots or defects possibly missed in inspection are covered.

If the contractor fails to meet the specifica- tions to any substantive degree, and the inspector has made a reasonable effort to gain compliance, then it is important that

Coating Project Specification 9-15

this information is brought to the attention of

9.5.10 Inspector’s Responsibilities

the supervisor or the owner’s representative

Regarding Coating Repair and

for determination of appropriate remedial

Remedial Work

actions. By making a clear, accurate, and The procedure for coating repair ( Figure objective report and recommendation, the

9.9 ) should be addressed in the specification inspector may have an important bearing on

and discussed in the pre-job conference. the decisions made.

• Ensure the areas to be repaired are clearly

In extreme cases, an owner could cancel the

identified and the coated surface properly prepared (e.g., feather edged by sanding)

contract, seek legal redress, or bring various

as specified

influences to bear to gain better cooperation. In some cases, it may be more economical to • Monitor the number of repair coats

applied, observe recoat times, and check

waive compliance with the specifications,

WFT and DFT as specified

finish the work, and accept the inevitable

• Document the work

lower coating performance. Such a judg- ment, however, must be made only by the designated supervisor or owner’s representa- tive, not by the coating inspector.

Figure 9.9 Runs and Sags