Final topcoating after erection is considered good practice. Topcoating 

 before erection is infrequent because of the damage problem during erection. 

 Damaged coatings should be removed. Abrasive grinding or wire brush pro- 

 cedures may be used for removal. The edges of the adjacent nondamaged 

 coated areas should be feathered and slightly roughened (for good adherence 

 of the repair coating). The repair coating system should be applied and 

 should overlap the previous coating about an inch or two. 



Touchup and repair topcoats are usually semigloss. Most industrial 

 coating systems utilize a semigloss topcoat rather than a high gloss topcoat. 

 Semigloss colors are much easier to match (in texture and color). High 

 gloss products tend to show up any slight variations of color or texture. 



Maintenance of a coating system is essential for long life and minimum 

 cost. In general, all critical areas including splash zones and the like 

 should be inspected at least once a year. Protective coatings, regardless 

 of type and service, will eventually wear or erode away. They require 

 periodic touchup and restoration. The effective service life of a coating 

 system will vary widely with the service condition, as well as coating 

 type, surface preparation and application. For good coating life, no fixed 

 maintenance program can be developed, unless accurate periodic inspection 

 records are kept. The most effective time for maintenance work will require 

 careful analysis of the periodic examination records. 



The expense of corrective maintenance work can be greatly reduced by 

 proper timing, as well as the choice of the proper repair materials. A 

 good maintenance program will initiate repair work before coating failure. 

 It is simple and inexpensive to apply a fresh topcoat. It is costly and 

 time consuming to remove a failed coating, clean the surface and reapply a 

 coating system (primer and topcoat) . In choosing a repair topcoat it is 

 important to select a product which will adhere to the old coating and one 

 which is compatible. It is recommended that product suppliers be consulted 

 in such choices. When the coating failure is greater than 10 percent or 

 there is widespread delamination, cracking or incipient surface rusting, it 

 is best to remove the old coating completely and recoat. The best maintenance 

 program is a good inspection program coupled with the application of a 

 fresh topcoat before excessive failure initiates. A good weathering 

 topcoat, such as an acrylic, can add many years of life to a coating system 

 at minimum cost. 



h. Specifications. A satisfactory coating system and protective 

 coating program begins with the specifications. Yet, many coating specifica- 

 tions are vague and wordy. All too frequently, the importance of developing 

 a structure is given so much time and preoccupation that the architect- 

 engineer underemphasizes the necessity for clear-cut coating specifications 

 to protect the structure. 



Writing appropriate coating specifications will do more than almost any 

 other one phase of coating work to achieve long life economical protection 

 in any harbor facility. These specifications play a conspicious role in 

 terms of both initial cost and a cost per square meter per year of service 

 life. 



Many specifications, primarily because of efforts to streamline this 

 aspect of the job or to place them in the category of "routine work," open 



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