If you skip this step, you are setting yourself up for cracked crucibles, wasted metal, and frustration.
Every new ceramic crucible must be seasoned before first use. This process strengthens the interior, prevents thermal shock, and creates a protective borax glaze that helps metal flow smoothly.
Why Seasoning Matters
Ceramic crucibles contain microscopic pores. When exposed to high heat too quickly, trapped moisture expands and can cause cracking.
Seasoning does three things:
• Drives off residual moisture
• Reduces thermal shock risk
• Creates a protective glass layer inside the crucible
If you blast a cold crucible with a full torch flame, do not be surprised when it fractures.
Step by Step: How to Season a Crucible
Step 1 Inspect for cracks
Always examine the crucible before heating. Even hairline cracks will expand under heat.
Step 2 Add borax
Sprinkle a light layer of borax flux inside the crucible. You do not need much.
Step 3 Heat slowly
Start with a low flame. Gradually increase heat. Do not immediately apply full flame.
Step 4 Rotate to glaze
Once the borax melts, tilt and rotate the crucible so the liquid borax coats the entire interior surface.
Step 5 Cool naturally
Allow the crucible to cool on its own. Never quench in water.
After cooling, the inside should have a smooth, glassy appearance. That glaze is your protective layer.
Melting Gold vs Silver
Silver melts at approximately 1763°F.
Gold melts at approximately 1948°F.
For both metals:
• Preheat the crucible gradually
• Add a small amount of borax before adding metal
• Use a neutral flame
• Heat evenly in circular motion
You know the metal is ready when it becomes fully liquid and fluid.
Silver should move like liquid mercury.
Gold should appear bright and mirror like.
Critical Safety Reminder
Never introduce wet metal into a hot crucible. Moisture can cause violent splattering.
Proper seasoning and controlled heating are not optional. They are what separate controlled melts from cracked equipment and ruined pours.
Recommended Gold Refining Supplies
If you're refining scrap gold, jewelry, or electronic components, using the correct chemicals and fresh reagents is critical for consistent results. These supplies are commonly used in the aqua regia gold refining process.
Hydrochloric Acid for Aqua Regia