Brad Walker wrote:Thanks to Lauri Levanto, we have a preliminary draft of an online dictionary of kiln-forming terms. Please check it out and let us know what you think.
This is a draft, not a final version, so comments are encouraged. If you have suggestions for improvement, terms to add, or corrections, please note them in this thread.
Here's the page:
http://www.warmglass.com/Dictionary-11.html
Corrections on BOLD
Bentonite can b used as suspension agent
Calcium Carbonate Ca CO3 whiting
Calcium Oxide Ca O Lime
plaster of paris Ca O4 . 1/2 H2 O
O is oxigen
Cerium Cerium oxide used for fine polishing. note if U can feel scratch with ur nail use pumace first, clean up then use cerium, keep wheel damp with cloth
Colloidal When a material is mixed with a liquid in so small particles that these do not settle to the bottom. Some colored glasses are made with colloidal metals that interfere with the light producing color. Two liquids can form a colloin COLLOID like in mayonnaise
Compatibility test To test compatibility pieces of different glass are full fused on a base glass. The tet TEST piece may show fractures - not compatible - or stress when viewed with a polariscope
Devitrification
Devit Result of devitrification. When glass is made the chrystalline ingredients are vitrified,melted to a liquid form. Devit is reverse of this process when chrystals form on OR WITHIN glass. Devit can be prevented or reduced by using oversprays.
Devit is glass molecules arranged in ordely fashion micro cristaline or larger cristals or both
In our normal glass the molecules R arranged in a random manner ( with some glasses this is not true )
Anti devit stuff works by making the glass 2 liquid so the cristals cant grow, also it will tend 2 disolve any neucleation points, so again it cant grow
Devit will only grow within a certain viscosity range, to stiff or 2 liquid n it cant grow
It also needs something 2 grow from like dirt or a scratch ( neucleation point )
It is this reason that devit usually only grows at an interface
Anty devit applied 2 light devit will mask it as it will B shiny n there may B a little disolving going on depending on temps
Devit usually incompatable but is OK up to a crertain size ( varies from glass 2 glass
Evenity EVENIVITY A WG term that refers to the uniformity of temperature in the kiln.
Flux use of can B used 2 stick glass together n assist in melting at a lower temp
Used 2 lower melt temp of colourants body stains on glaze
Body Stain
On Glaze
Glass enamel
Frit 1. Glass that has been crushed to small grains.
2. Ceramics: a composite powder used in glazing. Some toxic or otherwise difficult ingredients are enetered into the glaze mix as frit.
Frit is also a term used where a mixture of materials is heated whereby all the gassing n reactions r finished
This is then quenched n ground
Body stains, enamels, on glaze R made this way, it is usual 2 fire these much lower when manufactured
The advantage is that no or little gassing / reactions happen buring use
These can then B further softened with flux
Lapwheel UK - flat bed grinder
Opal Glass that is opaque or milky. See transparent and translucent can have cryistals with in it so can change on reheat ( devit troughout )
Peeking Visually monitoring the process in the kiln, with out opening the door so kiln not cool
Rigidizer Used to harden or rigidize forms made of soft ceramic fiber material colloidal alumina or colloidal silica SiO2
Neucleation point Something that devit grows from this can B dirt , scratch, or something cristaline see also devit
Striking A glass that is made like this can discolour on refiring
Bullseye uses this term to describe class that obteins the final color only after a second firing ,
