How to prolong the life of your galvanized trailer by taking care of its protective coating.
What is hot dip galvanizing for trailers?
Hot dip galvanizing is an anti-corrosion process that creates a protective layer of zinc on metal surfaces like aluminium and steel.
After manufacturing, your trailer is emersed (dipped) into a pool of zinc that has been heated to around 460 degrees Celsius.
This dipping process allows the hot zinc to flow through and around the channels and surfaces of your trailer chassis.
By coating the metal surfaces in zinc, your trailer becomes far-more resistant to oxidation and rust.
The galvanizing process is very effective at preventing metal corrosion, but some basic care and maintenance is required if you would like your trailer to last for many years.
To learn more about hot dip galvanizing, visit the Galvanizers Association of Australia
Caring for your galvanized boat trailer
Galvanized boat trailers are by far the most common form of trailers for boats.
As boat trailers are often towed along sandy beaches and driven directly into salt water, they are also the most susceptible to corrosion.
To reduce the likelyhood of your boat trailer rusting, you should always wash it down with fresh water and store it in a dry condition, especially after using it in salt water.
Allowing salt water to remain on your trailer will quickly dimmish the protective properties of the galvanized coating.
Salt crystals left on the surface of your trailer will again become salt water when the temperature of the steel drops below the dew point, which is almost every day during the cooler months of the year.
Rinsing and flushing your trailer with fresh water while paying particular attention to the inside of hollow sections, will help to prevent salt particles from accumulating in these areas.
To complement the protective qualities of your boat trailer’s galvanized coating, you can also apply a fish oil solution to areas that are susceptible to corrosion.
Thankfully, fish oil is now developed with a reduced odour and is a cheap and effective form of corrosion prevention for marine trailers.
It is also easy to apply using aerosol cans that allow the fish oil to penetrate into difficult to reach areas.
One negative aspect of using fish oil is that it can remain sticky, allowing sand to accumulate on the surface.
Caring for your galvanized box trailer and other types of galvanized trailers
Galvanized box trailers and trailers for lawn mowing are often used to carry garden waste and other organic material to the local tip.
Water leaching through organic waste can be corrosive and may attack the galvanized coating and the steel beneath it.
To avoid damage to the galvanized surface, you should avoid leaving damp garden refuse or soil in the trailer for prolonged periods.
Storing your trailer under a tree is not recommended, unless it is sufficiently protected from the accumulation of leaves and tree waste by a tarp or other covering.
Parking the trailer on an angle allows rain water and condensation to drain freely out of the tray and channels, reducing the risk of damage to the protective coating.
The appearance of hot dip galvanizing
Hot Dip Galvanizing is an industrial coating not a cosmetic coating. This means your trailer’s galvanized surface will not look as “pretty” as paint, and is likely to have cosmetic imperfections or abnormalities.
Imperfections are a normal part of the galvanizing process and are not considered “defects”.
Here is a list of abnormalities that may occur with hot dip galvanizing:
- It is possible that the galvanizing may not completely cover the entire trailer
- Some holes may need to be drilled after the galvanising process
- Cold gal may need to be applied to the trailer after the hot dipping process
- Steel may be warped or out of shape due to the heat of hot dip galvanizing
- The galvanizing procedure may leave runs or excess zinc build up in some areas of the trailer
- The trailer may have signs of grinding where excess zinc build-up has been removed
- You may notice white oxidization on your trailer due to high humidity during the galvanizing process
How to repair damaged galvanized coating
If you manage to damage the galvanized coating of your trailer and would like to repair it yourself, you can use a cold-gal (cold-galvanizing) spray pack to touch-up the damaged area.
This should be done as soon as possible to prevent oxidation of the metallic surface.
You can purchase cold-gal paint cans from Belco and other paint suppliers.
If you follow these simple tips, your galvanized trailer should last you for many years to come.