Forge welding Fluxes
One of the challenges of forge welding is preventing oxidation and contamination during the welding process, which can weaken the weld and compromise its strength. This is where forge welding fluxes come into play.
Forge welding fluxes are materials that are applied to the metal surfaces before welding to protect them from oxidation, contamination and promote a stronger weld.
In this article, I have covered the types of flux for Forge welding, the importance of forge welding fluxes, their properties, and how to use them effectively in the forge welding process.
What is Flux in Forge Welding?
Flux is a material used in forge welding to protect metal surfaces from oxidation and contamination during the welding process. It is applied to the metal surfaces before welding and helps to create a strong, durable weld.
Flux works by creating a barrier between the metal and the air, which prevents the metal from oxidizing and forming scale during the welding process. Additionally, flux can help to dissolve or absorb any impurities or contaminants that may be present on the metal surfaces, which can weaken the weld if not removed.
Types of Forge Welding Flux?
There are several types of flux that can be used in forge welding, each with its own unique properties and benefits.
Related Reading: Types of Soldering Flux.
Some of the most common types of forge welding flux include:
- Borax: Borax is a popular and widely used flux in forge welding due to its low cost and effectiveness at preventing oxidation. It is a white powder that is mixed with water to create a paste, which is then applied to the metal surfaces before welding. Borax can also help to dissolve impurities and contaminants on the metal surfaces.
- Silica: Silica flux is made from finely ground sand and is often used in combination with borax to improve the fluidity of the weld and reduce the melting point of the metal. Silica flux can also help to remove impurities from the metal surfaces.
- Iron oxide: Iron oxide, also known as “red iron,” is a natural mineral that is often used as a flux in forge welding. It is effective at preventing oxidation and can also help to remove impurities from the metal surfaces.
- Charcoal: Charcoal can be used as a flux in forge welding when mixed with other materials such as borax or silica. It helps to create a reducing atmosphere that prevents oxidation and can improve the quality of the weld.
- Welding flux paste: Welding flux paste is a pre-mixed flux that is easy to use and can be applied directly to the metal surfaces before welding. It typically contains a combination of borax, silica, and other materials to provide a strong and effective flux.
best Flux for Forge welding
The best forge welding flux depends on the specific application and the type of metal being welded.
| Flux | Features | Uses |
| Peterson #1 Blue Flux | Working temperature 1200-1600F | For brazing brass, bronze, copper, steel & cast Iron |
| Harris Type B Solar Welding Flux | Good quality | For brazing of various metals |
However, borax is a popular and widely used flux in forge welding due to its effectiveness at preventing oxidation and its low cost. Borax can also help to dissolve impurities and contaminants on the metal surfaces, making it a versatile and effective flux for many applications.
Silica and iron oxide are also commonly used in forge welding and can provide additional benefits such as improving the fluidity of the weld and reducing the melting point of the metal.
