Have you ever been awestruck by the stunningly beautiful and unique patina of Corten steel? The rusty, orange-brown color that develops over time is eye-catching from afar and reveals amazing details up close. But outside of just appreciating its beauty, if you’re looking to expand your skillset in welding or trying something new for a project – then learning to weld Corten steel can be both rewarding and challenging!
Corten steel, also known as weathering steel, is a group of steel alloys that are often used in outdoor architectural structures. Unlike regular steel, Corten develops a protective layer of rust when exposed to the elements, and this is what gives it its distinctive appearance.
In this blog post, we’ll look at how to weld corten steel, as well as detailed instructions on how to properly MIG/TIG weld corten. Let’s dive in!
What Will You Need?
Before we get into the welding process, let’s ensure you have all the necessary tools and equipment. You will need:
- Corten steel sheets or plates
- Angle grinder with a metal grinding disc
- MIG or TIG welder (depending on your preference)
- Welding gloves and protective clothing
- Safety glasses or welding helmet
- Welding wire or rod suitable for Corten steel
- Wire brush and chipping hammer
Once you have all of these, it’s time to get started!
9 Easy Steps on How to Weld Corten Steel
Step 1. Prepare Your Workspace:
The first step is to ensure that your workspace is clean, well-lit, and free of any flammable materials. You should have adequate ventilation to deal with the fumes produced during the welding process. Set up your welding equipment according to the manufacturer’s instructions and ensure your safety gear is in place.
Step 2. Prepare Your Corten Steel:
Before you start welding, you must prepare your Corten Steel to ensure a clean and effective weld. Begin by using the angle grinder to remove any rust or mill scale present on the surface of the material.
Be sure to focus on the area where you plan on welding, as a clean surface will result in a stronger weld. After grinding, use a wire brush to clean away any remaining debris. Remember to wear your safety glasses or welding helmet to protect your eyes during this process.
Step 3. Set Up Your Welder:
Now that your Corten steel is prepared, it’s time to set up your welder. If you’re using a MIG welder, make sure you have the correct shielding gas – typically a mix of argon and CO2.
If you’re using a TIG welder, you’ll need a tungsten electrode and an argon shielding gas. Set the amperage of your welder according to the thickness of the Corten steel sheet. Always refer to your welder’s manual for specific settings and guidance.
Step 4. Begin Welding:
With your workspace, steel, and equipment all prepared, you’re now ready to start welding. Position the torch from the steel at a 75 to 80-degree angle to allow for the most effective weld. Start with a tack weld to secure the pieces together.
Slowly move the torch along the seam while keeping the arc on the leading edge of the weld pool. Remember to maintain a consistent speed and distance to prevent overheating and ensure a strong, clean weld. Be sure to wear your safety gear at all times during this process.
Step 5. Clean and Inspect the Weld:
Once you’ve completed your weld, allow it to cool down for several minutes. After it’s cooled, use a wire brush or a chipping hammer to remove the slag from the surface of the weld. Inspect your work closely to ensure there are no visible defects such as cracks, porosity, or undercutting.
If you find any defects, you may need to grind down the weld and re-weld it to ensure a strong and durable connection. Safety glasses should be worn during this process to protect your eyes from any flying debris.
Step 6. Post-Weld Treatment:
After welding Corten steel, applying a post-weld treatment is recommended to help restore the protective oxide layer. This can be done by exposing the welded joint to the elements, which will allow the natural weathering process to take place.
Alternatively, various commercially available treatments can accelerate this process. Apply the treatment following the manufacturer’s instructions. This step is crucial to regain the unique aesthetic appeal of Corten steel after welding, giving it a uniform, rusty patina over time.
Step 7. Optional Grinding:
Depending on your project and its aesthetic requirements, you may choose to grind the weld to make it blend in with the rest of the steel. Remember to wear your safety glasses to prevent metal debris from entering your eyes.
Use an angle grinder with a flap disc to gently grind the weld until it levels with the surrounding area. Be cautious not to rub too much, which can thin the steel and compromise the joint’s strength. If you choose to grind, note that the ground area might not weather at the same rate as the rest of the corten steel.
Step 8. Final Inspection:
After completing all these steps, it’s time for the final inspection. Evaluate the weld and the overall piece for inconsistencies, weaknesses, or aesthetics. Pay particular attention to the weld – it should be smooth and even, with no signs of cracking or weakness.
The Corten steel should also begin to develop its characteristic rusty patina. If there are issues, address them until your project meets the desired standards. Remember, achieving a good weld on Corten steel might require a bit of practice, so be reassured if your first attempt isn’t perfect. Keep honing your skills, and you’ll get there!
Step 9. Maintenance and Care:
Once your Corten steel welding project is complete, it’s essential to take steps to maintain and care for it. The uniqueness of Corten steel lies in its rusting properties, which gives it a beautifully aged appearance over time.
However, this rusting can also lead to corrosion if not correctly managed. To mitigate this, periodic application of a rust stabilizer can be beneficial. Furthermore, keep your welded Corten steel object in a location where it is exposed to the elements but not in standing water, as this can hasten corrosion.
By following these steps and taking proper precautions, you can weld Corten steel like a pro.
5 Additional Tips and Tricks
- Use the Right Equipment: Welding corten steel requires the right equipment. Typically, the most appropriate method is gas tungsten arc welding (TIG), but shielded metal arc welding (MMA) can also be used.
- Choose the Correct Filler Metal: For optimal results, use a filler metal that matches the strength and weathering properties of corten steel. A common choice is a low-alloy filler metal.
- Ensure Proper Cleaning: Before welding, thoroughly clean the corten steel surface to remove any rust or dirt. This will help in achieving a cleaner, more efficient weld.
- Control Your Welding Speed: Maintain a consistent and controlled speed during welding. This prevents overheating, which can compromise the integrity of the weld.
- Post-weld Cleanup: After welding, clean the weld area and apply a coat of weathering steel primer to help the newly welded area match the patina of the surrounding corten steel.
With these additional tips and tricks, you are well-equipped to weld corten steel successfully. Always prioritize safety and follow proper welding techniques for the best results.
5 Things You Should Avoid
- Avoid Welding on Damp Surfaces: Welding corten steel in damp conditions can cause hydrogen cracking. This is why ensuring the steel is dry before starting the process is crucial.
- Don’t Use Mismatched Filler Metals: Using unsuitable filler metals could compromise the integrity of the weld, leading to potential failure over time. Always ensure the filler metal matches corten steel’s strength and weathering properties.
- Avoid Fast Welding Speed: Welding at a high speed can lead to an uneven weld and may increase the risk of weld defects. Maintain a consistent and controlled speed throughout.
- Pay Attention to Safety Measures: Welding, though a standard procedure, can be dangerous if safety measures are not observed. Always use appropriate personal protective equipment, including a welding helmet, gloves, and safety shoes.
- Avoid Neglecting Post-weld Cleaning: Properly cleaning and treating the area after welding can lead to premature corrosion and discoloration. Always clean the weld area and apply a weathering steel primer to protect and blend the weld.
Avoiding these common mistakes can ensure a solid and successful weld on your corten steel project.
Conclusion
We’ve gone over some essential details regarding how to weld corten steel and how it’s used to produce a stronger, more durable product. Understanding all the steps and safety protocols involved in working with corten steel is essential if you plan to take on any welding projects. The key tip is that when welding use a slag remover before any weld passes. With the right resources and planning, you can be sure your weld will succeed.
Remember that not all steels are the same, so it’s essential to ask yourself what type of alloy best works for your project and then research the techniques needed to join them together properly. If this blog post has inspired you to create a masterpiece of corten steel, why not dive in and start now?
All you need is some experience and a steady hand on the welder, and who knows – you could be making breathtaking sculptures in no time!
