Annealing

What is Annealing?

In glass bead making annealing refers to the process by which the glass is heated up to within the annealing range of the glass used to make the bead, held there for a specified amount of time (depending on the size of the piece) and then cooled down gradually at a constant rate (for example 1 degree C per minute). This eliminates the stresses within the glass that were introduced in the process of making the bead.

If these stresses are not removed from the glass then it may cause the bead to shatter or crack in the future.

(In silversmithing annealing is the process of changing the structure of silver to make it workable!)

Why you need to anneal your beads

If you are planning to make glass beads to sell then they must be annealed. This means that the bead is more durable and less like to shatter ruining the jewellery item that has been made

How to tell if your beads are annealed

There are a variety of tests that you can use to test if your beads are annealed some more "scientific" than others.

Bounce test

This means you can bounce your glass bead on a concrete or tiled floor and it will remain intact. This is not truly recommended although dropping does occur regularly by accident!!! This may lead to slight chipping of an otherwise totally acceptable bead!

Cold to hot test

This involves making your bead very cold i.e. putting it in the fridge and then transferring it rapidly to hot water. This is NOT recommended as the glass bead may be perfectly annealed but the thermal shock may cause it to shatter!

Polarising lenses

This is probabaly the most reliable method of checking your annealing schedule. This involves holding the glass bead between two polarising lenses up to a light source and looking for stresses in the glass. These show up as "cross" shapes in the glass. Please note: it can only be done on transparent beads.