Glass Frosting

[fx2121]

hello
I am having a problem with my glass getting a frost look to it when I use my bottom torch on my red max torch? pls help?

[rez cash]

first look up devit (Devitrification)


start making sure your glass is clean


get the glass hotter. you might just be working it too cold and if thats the case you should be able to flame polish the "frost" off

[fx2121]

first look up devit (Devitrification)


start making sure your glass is clean


get the glass hotter. you might just be working it too cold and if thats the case you should be able to flame polish the "frost" off

Yes read up on that could be I'm getting too hot for to long. Thanks for your reply

[JBob]

down with propane, up with oxygen!

[arghpeteypirate]

Are you using Schott or Simax?

[talonst]

Moving the glass cold or working it too hot for too long and burning out the flux.

Read Glass Alchemy's page on phase separation and devitrification at http://www.glassalchemy.com/phase_separation

[talonst]

Also found this interesting tidbit - its about quartz but probably applicable in many ways to boro as well.

Devitrification

Quartz exists in a state of imbalance. The atomic structure of quartz glass is a chaotic maze of atoms and atomic bonds. Devitrification is simply the quartz atoms rearranging themselves into an orderly, crystalline structure. Quartz only exists as a smooth, clear material because, during the manufacturing process, the atoms have difficulty rearranging themselves in an orderly pattern before the molten material cools into a solid material. Devitirification is caused primarily by two factors: contamination and atmosphere. Contamination, as it relates to quartz devitrification, typically refers to the introduction of alkali to the quartz. Alkali’s include sodium, potassium and lithium and are usually introduced to the torch as a result of contact with the oils present in the skin. Fortunately, simply touching the quartz will not necessarily promote devitrification. A catalyst must be present to start the process. In the case of quartz, the catalyst is heat, specifically 1000 degrees C. It is interesting to note that contamination may also be introduced to the quartz by way of water. Water drops on the surface of the quartz may attract contaminants and, when dried, the contaminants may remain on the surface of the quartz.

Atmosphere also has an impact on devitrification. Quartz is manufactured in a partial vacuum and, as such, has an oxygen deficit. In order to re-crystalize, quartz requires a more perfect stoichiometry (a 1:2 ratio of silicon to oxygen in quartz). As the atmosphere contains a fair amount of oxygen, there is always oxygen present to promote devitrification, but adding additional oxygen will cause quartz to devitrify faster. Temperature also plays an obvious role in devitrification. As high temperatures are necessary to cause devitrification, the higher the temperature, the faster the quartz will devitrify. This explains why torches used in high temperature applications like oil labs tend to devitrify faster than those used in water labs.

[BORO]

Yup , oil + heat makes a quartz nail look like poop .

[fx2121]

Yup , oil + heat makes a quartz nail look like poop .

Thanks I will keep burning away till I can get it right :)