tonycarillo Posted June 10 Report Share Posted June 10 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! Quote Link to comment Share on other sites More sharing options...
Hulk Posted June 10 Report Share Posted June 10 (edited) 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 Quote Link to comment Share on other sites More sharing options...
Jarman Porcelain Posted June 11 Report Share Posted June 11 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. Callie Beller Diesel 1 Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.