Knowing how to weld copper can be tricky, It is of high-quality, offers high resistance to corrosion, and can be used in various home improvement projects. This is why knowing how to weld copper can be beneficial when it comes to projects that require the use of copper.
Below is a guide on how to weld copper. We have compiled a list of tools and equipment that you will require as well as the problems with welding copper. Also, before you start welding copper, you should handle it safely and observe all necessary precautions.
Problems with Welding Copper
One characteristic that we all love about copper is how it is a good conductor of both heat and electricity. This feature, however, makes it a hard metal to weld. When welding copper, the heat spreads out through the entire metal instead of concentrating on the part that you wish to weld.
Welding copper is often perceived as a more complicated process compared to soldering. The reason for this, as explained above, is copper’s excellent conductivity to heat. Most people prefer soldering or brazing copper pipes because these two processes are less complicated. And soldering is a bit cheaper than some forms of copper welding.
Nonetheless, welded copper remains to be the strongest when compared to soldered or brazed copper. It’s because welded copper is joined together by fusion.
How to Weld Copper
Step 1: Wear Protective Gear
Before starting any welding task, you must put on full protective gear. Safety glasses should be worn to protect your eyes and a helmet to cover the entire head. This gear must be accompanied by a welding jacket that will protect your body from fire and sparks. The type of gloves to be worn should preferably be made of leather. You should put on leather boots to cover your feet. The reason why we are insisting on leather is that it doesn’t conduct electricity.
Step 2: Choose an Ideal Working Area
You need to be very keen when choosing a welding area. It should be well ventilated because welding does produce dangerous fumes. Kindly keep off your garage if it is stuffy and crowded. If you must work in a confined area, you need to have on a respirator to protect you from inhaling dangerous fumes.
Step 3: Be Cautious
You need to assess your welding equipment. There should be no live wires popping up, and if you are working outdoors, there shouldn’t be any free-flowing water. If you are carrying out the project at home, have an adult watching the kids and block them from coming to the work station. Also, have a fire extinguisher around.
Step 4: Use Clean Copper Only
Painted or dirty copper can release dangerous fumes when welded. It is for this reason why you should only use clean copper. Metals that have been previously painted can contain hazardous materials. And if you must use such, weld the metal in an open area.
Step 5: Choose The Right Copper
At the moment, there are three main grades of copper in the market. They include;
Oxygen-free Copper – It is the most readily weldable type of copper that offers the highest electrical conductivity. It contains at most 0.02% of oxygen.
Phosphorous (P)-Deoxidized Copper – The second most preferred type is P-Deoxidized copper, which prevents any risk of porosity during welding.
This type of copper may contain 0.05% of both arsenic and phosphorous.
Tough Pitch Copper – It contains the highest amount of oxygen in the form of Copper Oxide, making it the least popular type in the market.
Using the above two is the best choice for welding because it will allow the copper to retain the original bronze color after welding.
Step 6: Keep Off Alloys
Although it is possible to weld copper alloys, you need to know that each alloy will be welded differently. As a result, there might be some differences in thermal conductivity and expansion. You should only stick to pure copper.
Step 7: Use the Recommended Gas Ratio
The gas ratio you use will depend on the type of gas as well as the thickness of your copper. There are two main types of gases. There is the Tungsten inert gas and Metal inert gas. For all copper that is under 2 mm, it should have argon gas and applied up to 160A. The thicker the copper gets, the more you will have to adjust the gas and increase the amp.
If you are struggling with welding, you can always switch up to 100% helium gas. Compared to Argon, it has higher power, thus enabling you to apply heat to the copper easily.
Step 8: Preheat the Copper
Preheating copper is a necessary step because it allows the metal cool slower after welding, which results in a finer weld. At the same time, it also minimizes the chances of cracking. To preheat copper, you will have to insert it into a furnace until it reaches the desired temperature, which ranges from 50 degrees Fahrenheit to 750 degrees Fahrenheit.
Step 9: Start by Initiating an Arc to Get the Puddle
After the copper has been evenly preheated, the next step is to initiate an arc to get the puddle. An arc can be defined as a shooting line of electricity that is created between an electrode and copper. You will need to hold on to the arc for a couple of seconds before the puddle appears.
Step 10: Application of a Filler into the Puddle
Immediately a puddle appears, you should apply a filler onto it. This should be done gently. The filler helps the copper to weld properly. You can use either copper or any of its alloys as your choice of a filler.
You need to be fast when welding because the longer the puddle remains exposed, the more time you will be allowing copper to oxidize.
Step 11: Cool the Welded Copper
The final step in welding copper is letting it cool. This should be done slowly because when you do it too fast, it might crack. This is where preheating comes in handy.
What You Need to Weld Copper?
Here is a list of tool and equipment that you will need to weld copper;
- A welder
- Welding rods
- Welding mask
- Welding jacket
- Welding gloves
- A pair of non-conductive leather shoes
- Eye protection
- Filter mask
- Welding helmet
- Power supply
- Welding materials – copper
With the above guide, you can successfully weld copper without running into any problems. Please be informed that there are many techniques that can be used in welding copper. You should find the one that works best for you. Ensure that you do it safely. If it’s your first time, you might end up with a mess. This is quite normal. Welding copper is a learning process. And the more you practice, the faster you learn how to do it professionally.
Looking to learn more? Check this out: The 6 Types Of Welding And What They Are Used For