ContentsThere are many surface coatings and treatments for steel of varying costs and effectiveness. The best in most cases is the one which provides required protection at lowest cost over planned service life. The economics of steel protection have changed markedly in recent years. Typically, a galvanized coating now costs less to apply than a three or four coat paint system on all but very heavy structural members.
In general, galvanizing's lower first cost and longer maintenance free life ensure lowest total long term cost, regardless of the method of cost assessment applied.
In cases where the inital cost of galvanizing is higher than an acceptable alternative coating the longer maintenance free life of the galvanized coating usually ensures superior long term economics.
Selection from the wide range of protective systems for steel normally depends on economics. Factors which determine the economics of a given coating system for a particular application include:
1. Initial cost of coating
2. Costing life of first maintenance
3. Cost of maintenance
4. Hidden costs
In the majority of applications, hot dip galvanizing will provide a long, maintenance-free life without any requirement for maintenance painting.
There are ways of calculating the benefits or disadvantages of different methods of corrosion protection. The most common method is to calcualte the Net Present Value (NPV) of each method and compare the results. This calculation takes into account the cost of borrowing money, the initial cost of protection, susequent maintenance costs and the lifetime of the project. It is frequently used by companies to measure the likely outcome of a capital investment project.
