Generally, no, you should not sand bisqueware due to the significant health risks involved.
Understanding the Risks of Sanding Bisqueware
Sanding pottery is sometimes done to smooth surfaces or remove imperfections. However, when dealing with bisqueware (pottery that has been fired once), this process releases very fine particles into the air. A major component of clay and ceramic materials is silica.
According to our reference, "you don't want to sand your bisqueware like normal, because when you do it puts all that silica dust into the air, but breathing in silica dust can be extremely hazardous to your health long-term."
Why is Silica Dust Dangerous?
- Inhalation: When you sand dry bisqueware, microscopic silica particles become airborne.
- Health Hazards: Breathing in this dust, known as crystalline silica, can lead to serious and permanent lung diseases, including silicosis. This is a long-term health risk.
Alternatives to Sanding Bisqueware
Rather than sanding bisqueware, which is highly discouraged due to the dust hazard, it's better to address surface issues at earlier stages:
- Greenware Stage: Most smoothing and shaping should be done when the clay is in the greenware stage (before the first firing).
- Use tools like rib tools, sponges, or sureform rasps.
- Work over a catch basin or wet area to minimize dust.
- Wipe down surfaces frequently.
- Wet Sanding (with extreme caution): While still potentially risky, if sanding is absolutely necessary, it must be done while the piece is completely wet to keep dust out of the air. This method requires strict safety protocols, including proper ventilation and personal protective equipment (PPE). However, avoiding it altogether is the safest approach.
Key Takeaway: The risk of inhaling hazardous silica dust makes sanding dry bisqueware highly unadvisable. Focus on proper technique and finishing during the greenware stage to avoid the need for sanding post-bisque firing.
| Task | Recommended Stage | Safety Considerations |
|---|---|---|
| Smoothing Clay | Greenware | Minimize dust, work wet |
| Fixing Roughness | Greenware | Use appropriate tools |
| Sanding | Generally Avoid | High silica dust risk, severe health hazard |
| Wet Sanding | Last Resort | Requires strict safety protocols (wet, ventilation, PPE) |
For safety reasons, the best practice is to avoid sanding bisqueware.
