Welding galvanized steel is a common task in the metal fabrication industry, but it comes with unique challenges and potential health risks that welders need to be aware of. The zinc coating on galvanized steel, while providing excellent corrosion resistance, can pose serious dangers when subjected to the high heat of welding. This blog post will walk you through the proper preparation and techniques for welding galvanized steel, as well as the safety equipment you should consider using to protect yourself from hazardous fumes.
What is Galvanized Steel?
Galvanized steel is essentially iron that has been coated with a layer of zinc to protect it from rust and corrosion. This zinc coating is typically applied through a process called hot-dipping, where the steel is submerged in molten zinc. The resulting coating is durable and adheres tightly to the steel, forming a corrosion-resistant layer. However, when galvanized steel is welded, the high temperatures cause the zinc coating to evaporate, releasing zinc oxide fumes into the air.
The Dangers of Welding Galvanized Steel
The primary risk when welding galvanized steel is exposure to zinc oxide fumes, which can lead to a condition known as galvanize poisoning or metal fume fever. This condition occurs when welders inhale the fumes created by the vaporization of the zinc coating. Symptoms of galvanize poisoning can range from mild headaches and nausea to more severe flu-like symptoms such as chills, fever, vomiting, and cold sweats. In extreme cases, overexposure can be life-threatening.
Proper Preparation Before Welding
To minimize your exposure to zinc oxide fumes, it's essential to properly prepare the galvanized steel before welding. Start by removing as much of the zinc coating as possible from the area where you'll be welding. This can be done using a grinder, sander, or chemical stripping agent. Keep in mind that even with thorough preparation, some zinc oxide fumes may still be produced during welding, so additional precautions are necessary.
Signs of Zinc Oxide Fume Exposure
While welding, watch out for yellowish-green smoke, which is a telltale sign that zinc oxide fumes are being released. You may also notice white powdery particles in the air and a white residue around the weld area. If you begin to experience symptoms like headaches, nausea, or flu-like symptoms, stop working immediately and move to a well-ventilated area.
Preventing Galvanize Poisoning
There are several steps you can take to reduce your risk of galvanize poisoning:
- Ensure Proper Ventilation: Always work in a well-ventilated area, ideally with a fume extractor to pull harmful fumes away from your breathing zone.
- Wear Appropriate Safety Gear: Consider using a welding helmet with a Powered Air-Purifying Respirator (PAPR) system. These helmets provide a continuous flow of clean air, filtering out harmful fumes and particles.
- Drink Milk: Some experienced welders recommend drinking milk before, during, and after welding galvanized steel. The calcium in milk is thought to help neutralize the effects of zinc oxide, though this should not be relied upon as your primary defense.
Welding Helmet PAPR Systems and Fume Extractors
When welding galvanized steel, personal protective equipment (PPE) is crucial for your safety. A welding helmet with a PAPR system can be an excellent investment, especially if you frequently work with galvanized materials. These systems provide fresh, filtered air to the welder, greatly reducing the inhalation of harmful fumes. They also improve overall comfort, allowing you to focus on your work without worrying about your exposure to dangerous gases.
One of our favorite PAPR systems comes from Miller Electric. The Miller PAPR 2 Complete System comes with everything you need to protect against harmful fumes while on the job.
Additionally, using a fume extractor is highly recommended. These devices capture and filter the fumes directly at the source, preventing them from spreading throughout your workspace. Fume extractors come in various sizes and configurations, making them suitable for different types of welding environments.
For larger indoor jobs that don't have proper ventilation, the Miller Filtair Capture 5 Fume Extractor is a great choice. This machine is ideal for fabrication shops, as well as manufacturing and training centers.
For smaller jobs in tighter spaces where a large fume extractor won't fit, Lincoln Electric makes a portable fume extractor that will do the trick. The Lincoln X-Tractor Portable Fume Extractor will ensure you're still being protected even in smaller and more confined spaces.
Welding galvanized steel requires special attention to safety, from proper preparation of the material to the use of protective gear like PAPR systems and fume extractors. By following these guidelines, you can minimize your exposure to harmful zinc oxide fumes and avoid the dangers of galvanize poisoning.
If you have any questions about welding galvanized steel or need assistance selecting the right safety equipment, don't hesitate to reach out to Baker's Gas and Welding. You can call us at 877-930-56909 or email us at support@bakersgas.com. We're here to help with all your welding needs!
