Flip and Fire

"Flip and Fire" is a term was devised by Brian Blanthorn to describe a process to achieve crisp details in the final piece.

The process takes advantage of two things - heat and weight. The glass on the shelf side moves less than the top as it is not quite so hot, and the weight of the glass above keeps the lines the way they were cut. The glass on the top of the piece begins to move first and fill the gaps that are left between the pieces.

This piece has been assembled with the final upper surface on the shelf and the base sheet placed on top.

The simplest method to achieve straight lines is to fire the piece with the final surface down to the shelf. After fusing, turn over and clean any surface contamination, usually by sandblasting. Wash and polish dry. Then fire the new surface to a fire polish temperature.

The same piece fire polished after cleaning the fused glass.

This technique works best on pieces that are of one uniform thickness.


There are other factors at play in obtaining crisp lines. 

Fusing straight lines

In addition to the "flip and fire" approach, there are a number of other factors that contribute to sharp, crisp lines in a piece made with strips of glass laid on edge and fused.

Smooth glass will fuse straighter than strips of textured glass. The individual strips fit closer together, leaving less room for lines to wander and create a wavy appearance.

The quality of the cut of the strip is important. Straight strips with right angle edges and no flares make for crisper lines.

The thinner the strips, the less opportunity for movement in the fusing when they are placed on edge. Ideally, the strips should be 6mm wide. This is the thickness that glass tends to take up when full fused. The greater the width beyond 6mm, the less likely the lines will be straight.

The viscosity of the glass affects the crispness of the lines. A glass that is less viscous will tend to be more wavy than a more viscous glass. E.g., black glass, a less viscous glass than white, will tend toward waviness more than the white. This is not a variation between manufacturers; it is a variation within a compatible range of glasses.

The firing surface will have an effect. Firing directly on a kiln washed shelf will give crisper lines than firing on fibre paper of whatever thickness.

Damming the composition before firing will produce straighter lines. The dam holds the strips in place during the heat up and restricts any flow that would be caused by strips thicker than 6mm.