Galvanizing, or galvanization to give it full name, applies a coat of protective zinc coating to steel and iron to prevent rusting. The hot dip process is the commonest method, whereby an operator or a machine submerges the parts in a bath.

Two Ways Galvanizing Protects Iron or Steel

Galvanization delivers its benefits in two ways:

  • The zinc coating stops corrosive substances reaching the iron or steel for as long as it lasts.
  • The zinc acts as a sacrificial metal protecting the underlying iron or steel from corrosion.

This barrier however degrades over time. The zinc coating becomes thinner and thinner as corrosive substances consume it. The barrier also weakens with cutting and drilling, although these enjoy a measure of protection from adjoining surfaces.

How to Make Galvanizing Last Longer

  • Try to avoid using galvanized metal where relative humidity is greater than 60%, or you live near the coast where there is salt in the air.
  • Avoid direct contact with dissimilar metals such as brass, copper, uncoated iron, and raw steel. This applies to brackets, hinges, screws, bolts etc.
  • Rather use galvanized fittings and bolts, or at the very least galvanized washers / spacers if you have no other choice.
  • Cadmium-plated brackets and fasteners are an option in low humidity/ low salt areas. But cadmium is a sacrificial metal and it gradually degrades too.
  • Galvanized iron and steel are generally immune from lead, tin, aluminum, and of course zinc itself.
  • Several other factors also accelerate corrosion of galvanized surfaces. Acids, cements, moss and lichen all gradually take their toll.

Galvanization is Not a Universal Solution

Galvanizing iron and steel does add a measure of protection by buffering them from corrosive factors. In fact, if done correctly it could extend the life of these by up to 50 years in the right environment.

Therefore it’s always advisable to seek advice from seasoned professionals when considering using galvanized metals. If you do decide to proceed with them ensure  that your contractor:

  • Cuts the metal to size, and makes major holes before galvanizing.
  • Specifies the highest grade of hot dip galvanization from their supplier
  • Only use suitable brackets, screws, nuts, bolts and spacers throughout the job.

Valiant Exteriors publishes this information in the interests of promoting better services. Please call us at Calgary, Canada (403)829-1661 if we could be of any further assistance.

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