How to Prepare a Crucible

How to Prepare a Crucible

Borax is used as a base in flux when soldering jewellery metals such as gold or silver. It allows the molten solder to flow evenly over the joints. Borax is also a good flux for “pre-tinning” tungsten with zinc – for soft soldering to tungsten. Also used for forge welding flux, brazing flux & a constituent of arc welding flux.

Another great use for borax is preparing the crucible for melting by creating a glaze in it.

How to Prepare a Crucible

This is How to Prepare a Crucible:

  1. Fill your brand new crucible halfway with Methylated spirits, allow it to soak into your crucible.


  1. Heat up your crucible (be careful as the flame will be larger than usual due to the spirits), then pour in around 2-4 heaped tablespoons of borax powder (there might be some fluffy bits of borax flying around – this is normal)


  1. Concentrate your flame onto the powder until it starts becoming see-through glass gel.


  1. Swirl this glass around the crucible until it coats the whole inside & glazes the surface evenly.


Then its ready to use!


Always be careful when working with open flames, gas & metal- Safety First.


Don’t forget sprinkle some borax which will help keep the impurities out of the metal!