"Getting an Edge"

Page 3

Variations

At this point in the process, you have several choices, depending on the final look you want to achieve. If you want a high gloss edge, I’d recommending putting  the piece back in the kiln for a firepolish at approximately 1350-1390 degrees for 10 min. The exact time and temperature you need for this is something that you will need to experiment with in your particular kiln, but you should find a time and temp combination that will slightly round the edges without much distortion, and give a beautiful polish without devitrification. I highly recommend that this be a separate next step, and that subsequent slumping be done as a third firing at a lower temperature.

If you want the edge to have a matte finish, you may want to stop polishing after 220 or 400 grit, and possibly apply a sealant, such as Armor All, Liquid Lust’er, or Watco Oil. But, if you want more of a polish, although not with as high a gloss as you get from firepolishing, you can consider using a cork belt to get an even greater sheen. I would not recommend polishing the bevels with the cork belt, as you might strip the cork off the belt.

Unfortunately, it is at this point that deeper scratches that might have previously gone unnoticed may appear. When that happens, you may want to go back to a 220 or 400 belt, and start over. The color and pattern of the glass will dramatically affect the visibility of these scratches. A dark, solid color such as black will make these scratches the most obvious. A lighter, patterned design as in these photos is more forgiving.

To obtain a true, high gloss, optical polish using only coldworking techniques would require following the cork belt polish, with cork and pumice, and subsequently felt and cerium oxide. I have not used these steps in the creation of my pieces, but it is an option if you have the patience and tolerance for the additional mess these compounds can create.

Conclusion

As with all technical aspects of glass work, there are many techniques available to accomplish the same goal. What I have presented here is a basic example of how edge polishing can be done. You may find variations that work better for you, but I hope I have provided a starting point to help you create professional edges on your kilnformed glass work.