Borax Powder 1 kg – Soldering & Metal Melting Flux

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Borax Powder is a traditional flux material used in jewellery making, goldsmithing, silversmithing and precious metal melting. When heated, borax forms a glass-like flux layer that helps dissolve certain metal oxides and protects the metal surface from further oxidation.

Widely used in professional workshops, borax is suitable for preparing metal surfaces for soldering, coating crucibles and assisting with the melting of gold, silver and other compatible metals.

Supplied in a practical 1 kg quantity.

Key Features & Benefits

• Traditional jewellery flux: Commonly used in goldsmithing, silversmithing and metalworking.
• Helps control oxidation: Forms a protective glass-like layer when heated.
• Supports solder flow: Helps remove certain surface oxides and promotes solder wetting on properly prepared metals.
• Precious metal melting: Used as a flux during suitable gold and silver melting operations.
• Crucible preparation: Can be used to form a borax glaze on compatible crucibles.
• Powder form: Allows the quantity to be adjusted for different workshop applications.
• 1 kg pack: Suitable for regular professional workshop use.

What Is Borax Powder Used For?

1. Jewellery Soldering

Borax is commonly used as a flux when soldering gold, silver and other compatible metals.

During heating, metal surfaces can oxidise, making it more difficult for solder to flow and bond correctly.

Borax helps dissolve certain oxides and limit further oxidation, supporting cleaner solder flow when the joint has been properly prepared.

2. Gold and Silver Melting

Borax is used in precious metal melting to help manage oxide formation and some impurities.

As it melts, it forms a glassy flux layer that can collect certain oxides and help separate them from the molten metal.

It is commonly used in appropriate melting and refining workflows, although it does not replace a complete refining process.

3. Crucible Glazing

Borax can be used to prepare certain crucibles before melting precious metals.

When heated, it forms a glass-like coating on the crucible surface. This can help reduce metal adhesion and protect the working surface in compatible applications.

Not every crucible material is suitable for borax glazing. Always follow the crucible manufacturer's instructions.

4. General Metalworking

Borax is also used in selected metalworking processes where a flux is needed to help control surface oxidation during heating.

Its suitability depends on the metal, temperature and process.

How to Use Borax Powder

For Jewellery Soldering

1. Clean the metal surfaces and ensure the joint fits correctly.
2. Mix a small amount of borax powder with water to form a thin paste, or prepare it using your usual workshop flux method.
3. Apply a light coating to the area being soldered.
4. Heat the workpiece carefully using a suitable jewellery torch.
5. Add the appropriate solder and continue heating until the solder flows into the joint.
6. Allow the workpiece to cool as appropriate, then remove flux residues using a suitable cleaning or pickling process.
7. Important: Use a compatible solder and avoid excessive flux application. Borax is not suitable for every metal or soldering process.

For Gold and Silver Melting

1. Use a crucible and melting setup suitable for the metal being processed.
2. Heat the crucible and metal according to the relevant equipment instructions.
3. Add a small, process-appropriate quantity of borax flux where required.
4. Allow the borax to melt and form a glass-like flux layer.
5. Complete the melting operation using the correct professional procedure.
6. Allow the crucible and residues to cool safely before cleaning or disposal.
7. The required amount of borax depends on the metal, contamination level, crucible and melting process. Excessive flux can create unwanted glassy residue and may affect crucible performance.

For Crucible Glazing

1. Apply a small quantity of borax powder to the heated working surface.
2. Allow the borax to melt and form a thin glaze.
3. Avoid excessive coating or repeated glazing unless recommended for the crucible.

Safety & Handling

• Borax is a chemical product and must be handled with appropriate precautions.
• Use only in a properly equipped, well-ventilated professional work area.
• Avoid inhaling dust and fumes generated during heating.
• Wear suitable eye protection, gloves and protective clothing.
• Avoid skin and eye contact.
• Do not eat, drink or smoke while handling the powder.
• Keep away from children and unauthorised users.
• Store in a tightly closed, correctly labelled container in a dry place.
• Follow the product-specific safety data sheet (SDS), including reproductive toxicity warnings where applicable.
• Do not use for food, cosmetic, household or medical applications.