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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.
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.
When etching is complete, rinse and clean the cabochons. The surface will no longer be glossy, but the “scummy” devitrification should be gone.
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.
Here’s the firing schedule:
| Segment | Ramp | Target | Hold |
| 1 | 500° F / hr | 1000° F | none |
| 2 | FULL | 1400° F | none |
| 3 | FULL | 950° F | 30 minutes |
| 4 | 300° F / hr | 725° F | none |
Once the firing is complete and the kiln has cooled, remove your finished cabochons!
Now on to the wrap up...
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This is a great tutorial.
This is a great tutorial. Thanks for sharing!
After completing the
After completing the etching, you said the surface would no longer be shiny. Does the final fire polish help return the shine.
Nancy
I tried these this week.
I tried these this week. Loved 'em! Made another stack that needs to be cracked and refired.
Thanks!
Sandi
Tutorial
etching, then fire polishing
Nancy,
as the term "fire polishing" indicates, the point and effect are to achieve a polished, i.e., shiny, surface. This will also round small sharp edges that might for some reason be there. Fire polishing with a torch is used to achieve the smooth, rounded lip on glassware, such as tumblers and vases made from cutting wine bottles.
Piranga
Fused Glass, Wood, Beads, PMC, Ceramics
Usable and Wearable Art
Art for the Sake of Art
Etching: Methods and Safety
Lime-Away is another good product for removing kiln wash. A wire brush, either handheld or in a Dremel or other rotary tool works, too.
ALWAYS WEAR EYE PROTECTION WHEN USING ANY TOOLS, CAUSTIC OR ACIDIC CHEMICALS FOR REMOVING SCALE OR HAZE. Your eyesight is precious and irreplaceable.
WEAR GLOVES WHEN USING ANY CHEMICALS. Some chemicals, such as the fluoride compounds in Armour Etch, can cause severe eye and skin burns, and also can be absorbed through the skin and can cause damage to your bones and teeth. Good ventilation is a must, as inhaled fumes can cause serious problems also, both to your lungs, and as a route to your skeleton.
Get and READ the MSDS for chemicals you are thinking about using. This is a link for the Armour Etch MSDS http://cdn.dickblick.com/msds/DBH_60966z.pdf
Even though manufacturers and dealers do not always include MSDS with their products, mfctrs MUST provide them when requested to do so. Most MSDS can be found on-line these days. Many dealers will provide copies when requested.
Make informed decisions and use products safely. Think about others in your house/studio who might be exposed - children, spouses, pets, friends, coworkers. Protect them, too. If you can't, don't put them at risk.
Piranga
Fused Glass, Wood, Beads, PMC, Ceramics
Usable and Wearable Art
Art for the Sake of Art