Reduction Frit

Use reduction frits to create a metallic luster similar to a raku like effect.

To use, place frit on a marvering pad. Heat glass enough to pick up the frit and melt it fully into the surface of the glass for best compatibility. Form to its final shape. Allow the glass to stiffen, but still remain hot. Then, quickly heat the surface of the glass until molten. Avoid allowing the inside to become molten or the glass will probably loose its shape during the following steps. Quickly change the flame to a strong reduction flame (excessive fuel gas, lacking in oxygen) and rotate the glass in it. The reduction frit should start changing within two seconds and continue to change for up to ten seconds. You must flame anneal the glass in this reduction flame. If you change the flame to a neutral or oxidation flame, the metallic raku effect will disappear and you will have to repeat the process.

Powder covers the glass with a continuous luster. Large frit makes a broken, mottled pattern. Contains lead and therefore has a wider compatible range than other glasses. Reduction frit does not work with borosilicate (hard) glass, but does work with Effetre (Moretti) Vetrofond, Lauscha, Bullseye, Uroboros, Spectrum and Thompson Enamel.

Note: When you change to a reduction flame, the flame will probably increase in length. Be sure nothing is in its way. Also, the flame will feel hotter to you, but it is actually a cooler flame to the glass. The cooler flame eventually stops the process because, the glass will cool and no longer be molten. The metallic oxides will not be able to get to the surface. This is why you must quickly change the flame to a reduction flame and immediately put the glass in it. Practice is required. Timing is very important. If you are not satisfied with the look, repeat the above procedure.