ELEMENTS OF A TYPICAL COATING SPECIFICATION

Coating with the primer after the blasting of the manifold 3



Most specifications are formal, structured documents. What then do you expect to find in a good coating specification? A good coating specification will contain most or all of the following sections, each with information and criteria for the job:

1.      Scope of work: Describes the work to be done and when and where it will be done.

2.      Reference standards and codes: The specification will include a list of published standards referenced by particular sections or parts of the document.

3.      Safety

4.      Pre-job conference: A good specification will require a pre-job conference so that all parties will meet-the owner, contractor, coating supplier and inspectors as to review standards and work procedure for the project. Discussion should include all aspects of the specification but most likely to focus on: 

a.   Scope

b.   Safety practices

c.   Pre-cleaning inspection

d.   Coating materials and handling

e.   Application procedures

f.   Inspection (tools, methods, and sequence)

g.   Contractor submittals

h.   Change order, if any

5.      Surface Preparation: It is generally believed that fully 60 to 80% of all premature coating failures are attributable to inadequate surface preparation. This section is of course a very vital part of the specification.

6.      Coating materials (includes the coating schedule): Selection of coating materials involve matching a coating with the environment and in-service conditions to which it will exposed to. The specifier must be able to assess each area to be coated and rank each according to the anticipated operating conditions; then he determines which coating to use in each environment.

7.      Sampling coatings: The specifier may require the contractor or inspector to take retain samples of the coatings being used on the project. He may have to spell out the sampling procedure including number of samples to be taken labeling procedure, storage requirements etc.

8.      Workmanship: This has to do with the qualification of the work force: blasters, coating applicators etc and has to be in accordance to the principles of good workmanship described in SSPC-PA 1.

9.      Application: This section defines the approved methods of coating application:

a.   Brush

b.   Roller(hand or power-type)

c.   Air spray

d.   Airless spray

e.   Plural component spray

f.   Air –assisted airless spray

g.   Thickness(wet film, dry film)

9.      Work schedule(sequence of work to be done)

10.   Repairs and remedial coating work

11.   Inspection

12.   Documentation

To be continued.

Sent in by Richard Soroketa-Chukwuemeka Nwokocha, BSc. Industrial Chemistry, QC Inspector in Coating and Insulation.



DRY FILM THICKNESS (DFT) CHECK