Cabochon Clean-Up

There’s a good chance that your puddle cabochons will have some shelf primer stuck to their bottoms and possibly devitrification on their tops.  Both are easily fixed.

To remove the shelf primer, simply soak the pieces in vinegar. After 20 -30 minutes, shake the container gently and remove the cabochons. Any remaining shelf primer should now rinse away easily. If there is still shelf primer stuck to your glass repeat the process with a longer soak.

The most effective way to remove any devitrification is with a sandblaster.  Pressing the several cabochons onto a piece of duck tape will make blasting multiple pieces much easier by allowing you to blast a “strip” of cabochons at once.

If you do not have access to a sandblaster, you can remove light devitrification with glass etching cream.  “Armor Etch” is one brand that is widely available in the United States.

Paint the cabochons with a coating of cream and wait 30 minutes. For heavier devitrification, a longer wait or additional treatments may be required.

Removing light devitrification with etching cream

When etching is complete, rinse and clean the cabochons.  The surface will no longer be glossy, but the “scummy” devitrification should be gone.

Etched surface

Return the sandblasted (or acid etched) cabochons to the kiln for a final fire polish.  Use only shelf primer on the kiln shelf – shelf paper (like Bullseye’s “Thin Fire”) can cause slight hazing when fire polishing glass.

Fused glass cabochons ready to fire-polish.

Here’s the firing schedule:

1500° F / hr1000° Fnone
2FULL1400° Fnone
3FULL950° F30 minutes
4300° F / hr725° Fnone


Once the firing is complete and the kiln has cooled, remove your finished cabochons!

Now on to the wrap up…


Back to Fused Glass “Puddles” Start

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