WarmGlass.com

Hi everyone.
I am new to the bulletin board. I am currently trying to cast jewels to use in my lamp projects. The casting has proved easy, but I have been trying to fire polish the jewels and find they stay dull and matt. I applied superspray devitrification spray to them and slowly ramped up at approx. 400 degrees an hour (I am doing this manually) to 1350 degrees. I flash vented to 1000 degrees and annealed for 40 minutes. Can anyone tell me how to get a good polished surface on cast jewels

Hi Jerre: You asked a great question. As you know, Tiffany dragonfly jewels were cast in brass molds. It's rumored that Chicago Art Glass and Jewels still has a few originals. I hope someone on this board will have some suggestions. Have a great weekend!
Nikki

First of all- what kind of mold material are you using?? Some of the issues can be in the mold material. You want to cast into something that gives you a good finish to start- AND what temp are you casting at? If you are over firing- it affects the casting surface.

I make cast glass jewelry set into precious metals- I have tried to fire polish a piece that I cast into the mold material " Castalot" and I had sucess fire polishing it- although lost a little detail in the process. Since the glass pieces are small you dont have to slowly heat it up - I ramped 1000 an hour to 1360 (in a small paragon kiln) and held it for 2 minutes- then crashed it to 960 and closed the door.Hope this helps!

Hi Liz,
I used Hydroperm for my casting material and I must admit I ramped up to 1300 degrees slowly. I am planning to try "Back Magic" to get a good shine on the jewels. This substance apparently gives a shine at 960 degrees and therefore won't change the shape of the casting. I will let you know how it works.
Thanks for the input.
Jerre

Jerre- An artist I studied with, Ruth Brockmann, uses a 5-2-2 mold formula that produces a good finish. Its 5 parts Hydroperm, 2 parts Silica, 2 parts Hydrocal and 6 lbs of water (parts are by weight).The silica helps the release from the mold. You can also throw some chopped fiber glass strands in there for added strength. Anyway- just wanted to pass this mold formula to you in case you want to give it a try.Cheers!

Jerre-

I forgot to ask what is " Back Magic"?? And what is your resource for it?? thanks!

Liz,
Thanks for the mold formula. I will certainly try it. I read about Back Magic in the Contemporary Warm Glass Book, and it is available from Fusion Headquarters. i have ordered it and expect it this week. I will let you know how it works.
Jerre