Yes, you can weld copper – there are ton of videos online of people doing it (like this one and this one). Those are great visual examples of people using TIG to weld copper (the videos will also be available throughout the post. But for those of us who prefer text-based tips we wrote some out below.
The joining methods for copper mentioned below are:
Using TIG to weld Copper
Video Credits to Longevity Welding
Tips on how to TIG weld Copper
- Using a high temperature (roughly 300 degrees or 20 to 30 degrees higher than you would use for Stainless Steel)
- Consider preheating
- Take the property safety precautions (this stands for wlding all copper since the fumes you’ll produce are highly toxic)
- Aim to purchase de-oxidized copper because there have been several reports of individuals saying that oxidized copper tends to warp easily.
- Copper has a high coefficient of thermal expansion so, be prepared for warping.
- Your TIG machine needs to have about 300-400 amps to successfully weld copper.
Using MIG to weld Copper
This video (as you can tell) is done on a Copper-Nickel Alloy
Video credits to Copper Video
Tips on how to MIG weld Copper
- If the pieces are small enough you should consider preheating the pieces (as with TIG welding) because of how easily copper soaks up heat.
5 General Tips on How to weld Copper
1. Be as safe as possible
Due to the dangerous nature of welding it’s important to make sure that you take the necessary precautions when performing the activity. Make sure to have the correct gear, be in a clean place, and that there isn’t any flammable materials nearby. When you’re welding highly conductive materials like copper it’s important to make sure that you don’t touch the base metal being welding.
- Have the correct safety equipment such as a proper welding jacket, gloves, helmets, goggles, leather boots, etc.
- Make sure you’re in a space with appropriate conditions.
Welding tends to give off dangerous fumes so you want to make sure the area you’re in has adequate air flow. To do this, you need to make sure exhaust is kept near the ac, there is proper ventilation in the area, and you consider using a smoke extractor gun.
2. Have the correct filler material
You also want to make sure that your weld metal is much stronger than the base metal being welded. For example, when the copper alloy you’re using has at least 70% copper in it, you want to use a 30-70 nickel-copper filler material. Since the filler material is made mostly of nickel, it would be stronger than the base metal.
3. Remove all contaminants
Like most welding procedures oil, paints, and grease can ruin your weld if left on the material. Make sure that the copper you’re welding is free from all contaminants such as these before you begin the weld. Also make sure you know what types of materials you’re welding. For instance, copper-zinc-tin alloys cannot be welded to nickel-copper alloys.
4. Follow all of the basic procedures
Steel welding and copper welding are two totally different procedures. Make sure to prep your metals properly, paying attention to its thickness. Using a square butt prep is best for metals less than 3 mm thick. On the other hand, using a beveled prep is best for metals thicker than this.
5. Position your weld correctly
It’s important that you know that you can weld in a variety of different positions. Welding down-hand is great for copper welding. It makes it much simpler to weld and is much simpler to perform. If what you’re creating requires other positions it’s best to piece together your welds in a way that allows you to do down-hand welding.
Different procedures must be used when you’re welding copper. Understanding this and how to handle copper correctly will make sure you’re safe and able to weld the material together correctly. Understand the type of alloy you’re welding as well as the thickness of the material so that you can use the correct procedure to weld. Before you attempt an actual project try out your skill on smaller pieces of disposable metals.
How to weld thin sheets
When you’re welding thin sheets, one prefers to use the forehand welding method. One should prefer to use the backhand method when the sheet has a thickness of 1/4 in. or more.
For sheets of metal that’re up to 1/8 in thick a plain butt joint that has squared edges is what is preferred. If the thickness of the metal sheet is more than 1/8 in the edges should be beveled with an included angle of 60 to 90 degrees. Doing this insures penetration with spreading fusion over wider areas.
Scarf, butt, and lap joints are mainly used in brazing operations, regardless of if the joint members are round, tubular, flat, or has irregular cross-sections. Clearances to allow the penetration of the filler metal, except in large diameter pipe joints, shouldn’t be any more than .051 to .076.
Clearances of large diameter pipe joining’s may be .203 to 2.54 mm. The joint could be made with inserts of the filler metal or possibly the filler metal could be fed in from outside of the joint after it’s been brought to the correct temperature.
The scarf joint is typically used for joints where the double thickness of the lap isn’t desired and for joining bandsaws.
