If you are renovating your home, just starting your new project of welding zinc, or have something made of zinc, you may be thinking, Can you weld zinc?
The quick answer is yes; you can weld zinc! But welding is a specialized process. It requires knowledge and training as certain risks are associated. Therefore, you must follow specific safety guidelines.
You must know that zinc is a transition earth metal with a low melting point of about 420°C. Hence it can vaporize quickly and produces toxic fumes. You may inhale its poisonous fumes resulting in vulnerability and causing severe health hazards.
Let’s start from the beginning. So you can grasp the process.
- Why do you need zinc or galvanized steel?
- Zinc plated Vs. Galvanized steel:
- How can you weld zinc? Step-by-step guide
- Hazards Resulting from Welding Zinc
Why do you need zinc or galvanized steel?
Zinc plated Vs. Galvanized steel:
Zinc is a reactive metal used to construct corrosion-resistant bus stop benches, staircases, walkways, ladders, nuts, bolts, etc. It is used mainly in automotive and galvanization to increase steel durability.
The galvanization process involves dipping and coating the steel with the hot molten zinc to protect it from rust and corrosion. It also gives the steel a tough and thick layer of zinc.
Also, remember that hot-dip galvanization is not the only process of galvanizing steel; electro-galvanizing is also done for zinc plating.
It is the process in which zinc is applied using an electric current. Though it also protects the steel from rust, the coating is thinner, providing less resistance. The leading edge of zinc plating is cheap and easy to weld.
The purpose of both is to provide resistance to rust. But the application method of coating zinc is different. Thus, both offer different densities of the coating.
You can find both qualities of steel-coated materials in the market, and the seller may deceive you due to the slight difference in the final product. So it would help if you were extra vigilant while buying zinc plated steel.
How can you weld zinc? Step-by-step guide
You can weld zinc by following the steps below to avoid serious health hazards and get the best results.
1. Get the protected gears:
As discussed earlier, zinc can cause problems for welders due to its low boiling point and toxic fumes. So, there are a few pre-requisites if you weld zinc.
- Firstly, make a checklist to ensure the availability of all the required equipment.
- You must have the gears before starting: a welding machine, welding mask, welding gloves, an apron to protect yourself from heat, weld spatter, and a respirator to prevent the inhaling of Zinc fumes.
- Your workshop must have sufficient ventilation to allow the zinc fumes to quickly move out of the workshop.
2. Pre-weld checking of the equipment and safety gears:
To prevent any hazard to the health or the workplace, you need to ensure the reliability of the welding equipment.
- Ensure that the welding equipment is free from dirt and oil. Also, make sure that all welding terminals are in good condition.
- Make sure that the area is free of combustible materials and fire safety equipment is within easy access.
- Ensure that the electric cables are compatible with the desired voltage.
- Have a visual review of the workshop to ensure no airways are blocked or closed.
- Check the respirator for its expiration date.
- It is essential to check that the temperature is adjustable, especially in zinc, as zinc is usually welded at a relatively low temperature.
3. Scraping the surface:
The safest way to weld the galvanized or zinc-plated steel is to make the area welded free from zinc coating as much as possible because you would want to reduce the number of toxic fumes to the minimum. It is also essential to know that presence of zinc on the welded surface can also cause cracking.
- You can apply the diluted muriatic acid to the portion to be welded. However, the acid application must be made with proper safety protocols as this can be a complicated process if not carefully done.
- Use the sandpaper to scrape off the zinc coating from the steel.
- A grinder can also rub the zinc coating off the steel.
4. Temporary weld:
More commonly known as the tack-weld, this process is done before the final welding. It involves temporary welding the two pieces to hold them together for alignment. Remember to leave a small gap between the two tack-welded pieces as final welding can overlap the two pieces if there is no gap left. One critical thing to remember is that tack-tack welds must be rigid enough; otherwise, the two pieces may move apart, thus disorganizing the alignment.
5. Final weld:
After organizing the desired alignment, commence the final welding. This process is just like the normal welding process. The most prescribed welder for welding galvanized steel is the arc welder; an electric arc is created from AC or DC power source to generate a high heat temperature. Make sure you cover the entire joint to ensure the durability of the welded area. MIG weld method is also used for galvanized steel. However, it is less popular than arc-welding.
The two most commonly used arc-welding methods for galvanized steel are Gas Metal Arc welding and Gas Tungsten Arc welding.
Gas Metal Arc welding:
The gas metal arc welding process is becoming more widely used for welding galvanized steel because this process uses a shielding gas, which prevents the base from getting affected.
Gas Tungsten Arc welding:
The Gas Tungsten Arc welding process also produces a shielding gas, though. Still, it is slower as it uses non-consumable tungsten electrodes and damages the zinc-coating surrounding the welding area.
Once done with the welding, smoothen any rough surface with the grinding wheel to give a professional finishing and prevent any subsequent injury.
The welded portion will now be free of zinc; thus, the rust issue needs to be addressed by a new zinc coating;
- Zinc sticks can be used by rubbing them on the heated surface of the metal, and they will coat the metal with a new zinc coating. The new layer can blend with the original zinc coating if adequately practiced.
- Zinc spray is a faster method and is usually used when a significant portion needs to be coated. Note that a thicker than the original coating should be done in this method for the desired result.
Hazards Resulting from Welding Zinc
1. Can I weld zinc with a stick welder?
Stick welding is also known as manual welding or manual electrode. Since it is adaptable, many beginners and amateurs prefer stick weld to do most jobs.
Stick welding can weld all types of metal, including zinc-plated steel. You can fuse zinc using a deep penetrating rod that can go through the layer.
As it does not require shielding gas, thus you can use it easily to perform outdoor work.
2. Can I remove the zinc coating by burning it?
Usually, zinc coating is removed by grinding, but welders also burn off the zinc or push it back from the weld area. However, you can not ignore the toxic zinc oxide that is released while burning off zinc.
Thus, it is suggested to use a well-ventilated area for burning the zinc away from the welding surface to minimize the inhalation of zinc oxide. Inhalation of zinc fumes could cause serious health hazards.
3. Which type of rod should be used for welding galvanized steel?
Most welders prefer E6010 and E6011 cellulosic rods for galvanized steel. Cellulosic roads have a flux covering. E6010 and E6011 cellulosic rods are 60- 70% stronger than others.
It can burn the galvanized steel and can go deep into the metal. These rods have a thin covering, thus allowing welding in windy conditions.
You can weld zinc plated or galvanized steel by following the abovementioned steps. Always remember that you have all the right equipment for welding, protective gear, practice, and knowledge of the potential hazards. Regular equipment checks are essential. Nevertheless, you must be aware of the first-aid steps to take in case of any reaction from the zinc fumes.