Do you want to install pipelines without getting them rusty over time? The best solution we would recommend to you in such a situation is to use a suitable-size galvanized pipe. These pipes are coated with zinc that protects them from rusting over time.
But, can you weld galvanized pipe? Yes, welding galvanized pipe is similar to simple steel pipe, but when galvanized pipes are welded, they produce hazardous fumes dangerous to your health. It is recommended to wear protective gear and perform the galvanized welding process in a ventilated environment.
Read the blog to the bottom to learn about welding galvanized pipes using ARC and MIG welders.
What is Galvanized Pipe?
Before getting to the main discussion of today’s pick, we decided to look at the general explanation of galvanized pipe so it will be convenient for you to learn complex things later in this article and better understand the process.
Galvanized pipes are made of steel pipes, but they are coated with a protective zinc layer so the pipes can stay safe from rust and corrosion. The applications of galvanized pipes include sewer pipelines, railing, fencing, irrigation system, scaffolding, and many others.
Hazards of Welding Galvanized Steel
While galvanized steel offers excellent protection against rust and corrosion, it can be hazardous to weld. When you weld galvanized steel, the heat from the welding process causes the zinc coating to vaporize creating fumes that can be harmful to your health if inhaled and cause symptoms such as headaches, nausea, dizziness, and respiratory problems.
How to Weld Galvanized Steel Pipe with an ARC Welder?
Welding a galvanized pipe is not as simple as it seems. You need to consider safety measures and precautions while welding galvanized pipes as it involves risks.
The things or materials you require for welding galvanized pipe using an ARC welder are shown in the picture below.
1: Setting Up the Work Area & Wearing Protective Gear
After gathering all the materials, the first step of welding galvanized pipes is to set up the workplace according to your needs and work. Wear protective welding gear with gloves, an apron, a mask, and a high-quality respirator.
Next, set up a fume extractor at a very small distance from where you will weld. The fume extractor will immediately absorb all welding fumes so you do not feel suffocated.
Our suggestion is to carry out galvanized welding process outdoors, so you don’t have to worry about the zinc fumes that extract from the pipe when welding. But, still, you need to prevent the fumes at any cost.
2: Grinding the Zinc
The next step you have to follow here is grinding the area of galvanized pipe to remove the zinc coating as it can prove dangerous while making contact with the pipeline welding machine.
You can use 220-grit sandpaper to grind the galvanized pipe manually, or you can go with a low-setting grinder to wear off the zinc coating. Grinding the galvanized pipe and wearing off the zinc coating will also help you get a perfect cut with complete accuracy and precision.
We suggest you use a welding lens and a respirator while grinding off the zinc so its dust does not get into your eyes or throat, though it’s not dangerous as zinc fumes. But still, ensuring safety is recommended.
3: Placing the Pieces Together
The third step of the procedure is to place the steel pieces together. Set up your pieces according to your need. You must ensure the place you are using to weld is completely non-combustible and non-flammable to avoid any kind of accident or mishap.
You can use a clamp to place the small pieces together for welding. If you want to weld a hole, keep the pipe on the surface with the hole facing up and start welding.
The next and most crucial part of following the procedure is to weld the pieces together using an arc welder or other type of welder according to your work.
First, you must choose a welding rod based on features and size compatible with your work. Use the arc welder in the place where the pieces meet.
Start the arc welder by pressing the trigger and keep welding in a flow for the best and most efficient results. The advantage of an arc welder is that it does not create any sparks so you can work seamlessly for an effective experience.
5: Finishing it Off
Once you have damaged the zinc coating, you are now supposed to spray the welding surface with zinc-enriched paint, which gets rusted.
While galvanizing the pipe with zinc spray, we suggest you use a welding lens and respirator and spray from at least 14-16 inches.
How to Weld Galvanized Steel Pipe with a MIG Welder?
MIG welder, as the name implies, is a process that uses inert gas. It’s capable of producing cleaner welds than flux, as it does not create much slag compared to flux. Unfortunately, the MIG process is not applicable for welding galvanized steel pipe.
The picture below shows the steps you need to follow to weld galvanized steel pipe using a MIG welder.
1: Switching MIG Wire to Flux
MIG wire is not capable of carrying a galvanized pipe weld. So, you need to switch this wire to the flux core. Reverse back the standard wire to its spool, and when it reaches the ends, pull out the spool and tie the end of the extracted wire to the spool.
2: Put in the Flux Wire
You need to replace the current drive roll because the flux core is hollow in nature, and the current roll breaks it. Use one with minor serrations, which allows the movement of wire to the gun without damaging the wire. You can easily replace the drive roll by just removing the screw.
3: Switching Polarity (Positive to Negative)
The welder works on positive(DC) polarity with MIG wire, so you are required to change it to negative (DC) polarity to work it with flux core welding. You can change polarity by switching a wire inside the welder that connects it to the gun from positive to negative.
4: Grinding the Zinc Coating
Get rid of the zinc coating using 220-grit sandpaper or a grinder; before doing so don’t forget to wear a welding lens or respirator to avoid zinc dust in your eyes or throat. Once the zinc coating is removed, clean the pipe with a towel.
5: Welding Ungalvanized Pipe
Commonly, the MIG welding process pushes the weld pool forward. But welding on steel pipe requires you to pull rather than push it.
Pushing the weld pool could cause leaking of the weld or porosity. So pulling it is recommended as it prevents the pool from being contaminated.
6: Galvanization of Pipe
After performing the whole welding process and damaging the zinc coating completely, you are now supposed to coat again using a galvanization compound to prevent it from corrosion and rusting again.
TIPS to Weld Galvanized Steel Pipe
Safety Precautions for Welding Galvanized Steel
Before welding galvanized steel, it is essential to take the following safety precautions to minimize health risks and protect equipment:
- Use Proper Ventilation: Welding should always be done in a well-ventilated area, ideally with local exhaust ventilation. If ventilation is insufficient, use a respirator that is approved for welding.
- Use Proper Protective Equipment: Wear protective gear such as gloves, goggles, and long-sleeved shirts to prevent skin exposure to fumes.
- Clean the Surface: Ensure that the surface to be welded is clean and free of any debris or contaminants that could interfere with the welding process.
- Use Low Heat: Use low heat when welding galvanized steel to minimize the amount of vaporized zinc and fumes.
What is recommended welding rod for galvanized steel?
The recommended welding rod for galvanized steel is generally E7018. This type of electrode is preferred because it provides better penetration and produces a smoother weld. However, E6011 can also be used for welding galvanized steel.
Is drinking milk after welding beneficial?
When welding galvanized metals, a fume is extracted them that could cause metal fume fever upon inhaling. Many welders consider drinking milk the best treatment to avoid severe symptoms. However, many claim it is a myth just.
Welding a galvanized steel pipe is not rocket science, provided you do it with proper procedure. Also, do not forget to take precautionary measures such as wearing a full welding suit, including a welding mask, apron, gloves, and respirator. Ensure the place has good ventilation so you do not feel uncomfortable.[/su_note]
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