Should You Repair or Replace Galvanized Steel? 3 Factors to Consider
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Galvanized steel is one of the best materials to use when you need reliable corrosion resistance on the job site. But when something goes wrong, should you repair or replace galvanized steel?
Because the zinc coating on galvanized steel has unique, self-healing properties, it takes something significant to damage it to the point where it needs repair.
But when something does damage the coating, it is important to address it right away. If the steel underneath the coating is visible, rust could start to form and compromise the performance of the materials.
Understanding your options if your galvanized steel is showing signs of rust or damage will help you make the best decision quickly. So, here are three things to consider when you have old or damaged galvanized steel.
First Consideration: How Large is the Damaged Area on the Galvanized Steel?
The first consideration when deciding whether to repair or replace your galvanized steel is the size of the damaged area. If the area in question is too large, it may be irreparable.
ASTM has strict rules about how large an area is repairable on newly galvanized steel materials. But if the damage is on older pieces of galvanized steel in the field, any size repair is permissible. The main question is whether it is the best approach.
How Can You Repair Galvanized Steel In the Field?
There are a few ways to repair damaged galvanized steel in the field. The most popular are zinc-based solders, zinc-rich paint, and metallizing.
Each of these has its own pros, cons, and specifications about how to use it and when it is not advisable. The main purpose of all three of these techniques is to salvage the zinc coating itself. While they may also be able to repair and strengthen the steel itself, solder or paint will not be able to fill in a corroded hole or restore the integrity of a piece of steel that is falling apart.
For all three of these methods, it is also important for the galvanized steel to be clean and dry before repairs begin. This can be difficult, depending on the location of the damaged steel.
If you are dealing with a large area of damage (many inches across) or damage that is deeper than the coating and surface rust, replacing the steel is likely your best option.
Second Consideration: Does the Galvanized Steel Need Repairs in One Area or Many?
One common sign of galvanized steel deterioration can be many smaller areas of damage. Unlike one dented or scratched area, various small patches of damage or rust can be a sign of a deeper issue. Before working on repairing those small areas, it is a good idea to assess the quality of the galvanized steel.
Depending on how many smaller areas have damage and how deep the damage is, you may be facing a piece of material that was poor quality from the start. When steel is not galvanized the correct way, small bumps under the surface may form. There may also be tiny pinholes in the zinc coating itself. Over time, these slowly allow water to seep into the steel and cause corrosion.
While the methods for repairing galvanized steel are well-suited to small repairs, you do not want to spend the time and money repairing steel that is already compromised.
Always Inspect Your Galvanized Steel
This is one good reason to inspect your galvanized steel as soon as it arrives at your job site. If any imperfections are present from the start, it will be easier to work with the manufacturer to have the steel repaired before it becomes part of your build.
Another way to avoid this is to work with experts in the industry, like our team at South Atlantic. We combine ASTM industry standards with our own 25-point quality assurance process to make sure we only deliver the highest quality galvanized steel to our customers. You can learn more about our galvanizing division, and reach out to us today for a quote.
Third Consideration: What is the Age and Location of the Damaged Galvanized Steel?
The final consideration when you are deciding between repairing or replacing your galvanized steel is the age and location of the damaged material.
As we mentioned before, there are three main options for repairing galvanized steel. You can solder using a zinc-based alloy to fill in holes or join new pieces of steel to existing ones. When done correctly, this is a great option for repairing the zinc coating. However, the need to both prepare and heat the steel correctly without overheating any materials around it can be difficult in the field.
- Zinc-rich paint is easier to apply but is only suitable for touch-ups of the surface. So, if your steel has more significant damage than a few surface-level scratches, the paint will not be an effective option.
- Metalizing can be a great option to re-protect a compromised area of steel. The most important thing to remember when metalizing an area of steel is the coating thickness. The zinc must be sprayed on thick enough to match the corrosion-resistance of the original zinc coating. This is hard to do well in small, hard-to-reach areas of steel.
These Areas May Need More Frequent Inspections
All three repairs are just that: they are repairs to damaged materials. This means those areas will need more frequent inspection and maybe touch-ups to maintain the same hassle-free corrosion resistance the original coating had.
Sometimes the best way to ensure the greater longevity of your build as a whole is to cut out and replace the damaged areas of steel before they compromise more than one area.
At South Atlantic, We Have Answers to All of Your Galvanized Steel Questions
When galvanized steel is manufactured correctly, there isn’t much more you can do to increase its longevity. And that is why working with our team at South Atlantic is the best choice for building with materials that last.
If you have any questions about using galvanized steel for your construction project, reach out to our experienced team. With decades of experience in the galvanized steel industry and long-standing relationships with American steel factories around the country, we are your best resource for advice before you build.
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Sources:
American Galvanizers Association, “Coating Specifications,”https://galvanizeit.org/specification-and-inspection/coating-specifications/astm-specs#post:~:text=Galvanizing%20Supporting%20Specifications-,ASTM%20A780,-Practice%20for%20Repair
