Is “welding” copper possible? Absolutely. The trick is establishing the ideal joining method for your application.
Here’s a look at the different processes for welding copper, plus how your interior framing design can benefit from them.
Welding Copper: The Possibilities
1. TIG Welding
TIG welding is an option if you’re the risk-taking type.
Due to its high conductivity, the base material (copper) acts as a heat sink, so the welds need to be hot and fast. The heat associated with this process will cause that thin base to warp and change shape.
If you’re welding thin material that needs to maintain its shape, TIG welding may not be for you.
2. Silver Soldering
Silver soldering requires the least amount of heat and does not deform or discolor the base metal the way welding or brazing does.
The solder material does, however, leave a silver color at the seams. You can “pickle” these seams in an attempt to darken the color, but ultimately you won’t get as close to a color match as brazing or welding will.
3. Silicon Bronze Welding
Silicon bronze is a kind of hybrid MIG welding/brazing technique. You can use a MIG welder and gun to essentially braze the materials together. Using MIG equipment and silicon bronze welding wire makes joining copper an easier, more repeatable quality process.
The silicon bronze wire heating requirements aren’t enough to melt the copper base metal. This allows you to join thinner materials with little risk of melting or warping. You’re left with a yellowish filler material that can be polished and will have a similar color to your copper base material.
How can you put this technique into action when fabricating red metals?
Think of a Dahlstrom corner base moulding made of copper. When that corner joint has to happen, we can use silicon bronze to make it a clean, smooth joint between two mitered pieces at the factory. This option makes field work simple by limiting cuts to straight ones only.
You can improve your door casing design in a similar way. See how the piece would be attached? You’re basically making a picture frame out of the copper casing and cladding a flush metal door frame. Again, Dahlstrom would use a silicon bronze welding technique to do this.
4. BrazingBrazing is popular in jewelry making because it doesn’t melt the base metal and there are new filler wire materials available to match the metals and their colors. These wires require higher heat than a lower-temp silver solder but offer a better color match to the base metal.
Most soldering is done at temperatures ranging from 350-600 degrees F. Copper brazing is performed around 1,100-1,500 F.
Your Application, Your Look
The end use of the item you want welded greatly impacts the joining method you should choose. Experimenting with the soldering and brazing techniques perfected by jewelry makers can produce some beautiful looks and seamless joints for high-end metal moulding installation and furniture accent projects.
When you cut metal, the resulting ends can be sharp. That tends to scare installers away. The idea is that you find a crafty manufacturer who will pre-miter and pre-weld your pieces. By smoothing out these corners in the factory, you’ll avoid having a dangerously sharp edge where the two points meet. Remember also that Dahlstrom Architectural Mouldings’ optional pre-fabricated 90-degree joints can use any of our metal mouldings in not only copper, but brass and bronze as well.
As always with metal design components, let’s be creative, and let’s work with installation-ready accents!