Silicon Dioxide Powder

[tonycarillo]

Hey guys, so i've got this Silica 200# powder from my local pottery shop and I might need some insights on whats its main purpose and benefit. I've never worked with it before and just wanted to know more!

[Hulk]

Typically used as part of glaze formulations, it is a primary ingredient!

For low and mid fire glazes especially, the finer (smaller particle) 325 mesh is recommended over the 200*; see "The difference between Silica 90 and Silica 45" about third of the way down the page, here: Silica (digitalfire.com)

Silica can be an important ingredient in clays as well.

Dust control can be - it is - important when working with Silica (and other fine powdered materials).
 

*I'd mistakenly bought the 200 mesh, which may have been a factor in my struggles to eliminate crazing in my liner glaze.
Between lowering the COE (via formulation change; thanks to this Forum for support and specific information and suggestions), adding a smidge of lithium (via Petalite), and an extended hold (100°F below target/peak temperature - "drop and hold"), the crazing seems to be well under control.
Still, I'm looking forward to getting a sack of the 325 mesh!

Edited June 12 by Hulk
mesh detail, meh! and thanks

[Jarman Porcelain]

On 6/10/2024 at 11:04 AM, Hulk said:

Typically used as part of glaze formulations, it is a primary ingredient!

For low and mid fire glazes especially, the finer (smaller particle) 325 mesh is recommended over the 200*; see "The difference between Silica 90 and Silica 45" about third of the way down the page, here: Silica (digitalfire.com)

Silica can be an important ingredient in clays as well.

Dust control can be - it is - important when working with Silica (and other fine powdered materials).
 

*I'd mistakenly bought the 200 mesh, which may have been a factor in my struggles to eliminate crazing in my liner glaze.
Between lowering the COE (via formulation changes), adding a smidge of lithium (via Petalite), and an extended hold (100°F below target/peak temperature - "drop and hold"), the crazing seems to be well under control.
Still, I'm looking forward to getting a sack of the 325 mesh!

You can go even further, I have a 650 mesh silica I use in glazes where I need total silica melt to control crazing, such as with crystalline or low fire clears for ultra low expansion bodies. It is a luxury, you get such good melt.