What type of Finishes are available?

Hot Dip Galvanizing (HDG) - Hot dip galvanizing after manufacture is an excellent, economical protective finish used on support systems in many industrial and commercial applications. The galvanized coating is applied as a final manufacturing process by immersing a steel component (after various pre-treatments) in a large bath of molten zinc; the zinc forms an alloy with this the steel substrate and protects the steel from corrosion as above. The life of a zinc coating is directly proportional to its thickness but in different environments this life does vary. However, because hot dip galvanizing has been used for many years its life in diverse environments has been well established.

In the presence of certain atmospheric pollutants (such as sulfur dioxide in industrial areas) or when installed in an aggressive coastal or marine environment the rate of dissipation of the zinc will be accelerated; however in most situations hot dip galvanizing remains an extremely effective and economical corrosion resistant finish.

Pre-galvanized (PG) - A zinc coating can be economically applied to steel sheet immediately after its manufacture; the result, pre-galvanized steel can be an attractive, bright material which is suitable for non-arduous environments. Pre-galvanized (or mill galvanized) steel is produced by unwinding steel coil and passing it continuously through a bath of molten zinc and then past air jets to remove excess zinc from the surface. The process is closely controlled to produce a thin, even and ripple free zinc coating with very few imperfections. Because this pre-galvanized steel coil must then be cut to shape during subsequent manufacture of support equipment, the edges of the finished components will have no zinc coating. This aspect, together with the relatively light zinc coating provided by the process, make pre-galvanized service supports suitable for indoor, low-corrosive environments (particularly where an aesthetically attractive appearance is important) but unsuitable for humid indoor or outdoor applications.

Other applied finishes - Powder coating may be applied as a protective finish but more generally it is requested as a decorative layer applied to systems already protected by a zinc coating.

Stainless Steel - For most practical purposes stainless steel can be regarded as maintenance free and suffering no corrosion. Inevitably there is a relatively high price to pay for these attractive properties but, in aggressive environments or where the cost or inconvenience of gaining subsequent maintenance access is prohibitive, this initial cost premium may well be justified. Stainless steel contains a high proportion of chromium (usually at least 11%) and the steel’s remarkable immunity to corrosive attack is conferred by the chromium-rich oxide film which occurs naturally on its surface. This invisible film is not only inert and tightly bonded to the surface; it also re-forms quickly if the surface is damaged in any way. The fire resistance of stainless steel is particularly noteworthy; tests have demonstrated that stainless steel cable supports can be expected to maintain their integrity for considerable periods even when exposed to direct flame temperatures exceeding 1,000°C. This may be an important consideration where the electrical circuits being supported provide for emergency power or control systems.

A stainless steel surface will have excellent corrosion resistance due to the chromium oxide layer on the surface of the product. With some stainless steels however, the surface areas can become subject to corrosion due to the depletion of chromium during welding. To overcome this problem welded stainless steel products are often pickled and passivized after welding.