Showing posts with label Firing dichroic glass. Show all posts
Showing posts with label Firing dichroic glass. Show all posts

Thursday, April 22, 2010

Glass cabachons



For the longest time I've been wanting to make my own dichroic cabs. I looked for books on the subject, searched the internet and talked to another jewelry artist who makes them. One would think that my search resulted in lots of clear information. Yes and no. Somehow, I just couldn't quite grasp exactly what was needed.

The book I bought, Introduction to Glass Fusing by Petra Kaiser, was an older book but was highly recommended for a beginner. It's mostly about fusing, but there was a couple of pages on making cabs. It had very good photos showing different numbers of layers and how to stack the glass

As usual, I overdid it when purchasing supplies to make the cabs. I now own six colors of transparent glass, one color of opaque glass and a hodgepodge of dichroic glass scraps. Besides the glass, I bought the Morton glass cutting system with the mat and button, a pair of running pliers, two glass cutters, glass tack and firing paper.

As usual, I bought too much. I have enough glass to make thousands of cabs. The Morton system is nice but for my small pieces I seem to have more luck cutting my glass on the PMC work sheet placed on top of a piece of linoleum.

The running pliers just came yesterday and they are a God send (thank you Phil.) I tried the red button and (the other red piece that came with the Morton set) with not much luck. Last week Phil (one of my students) brought in some clear glass, stained glass and running pliers and told me how to use them. (I guess I'm a visual learner.) When he came back after his yoga class, I had managed to create quite a pile of jagged broken glass. It seems that I was holding the running pliers parallel to the score line. (I could have sworn I saw that somewhere...... and sure enough it was in my book. But I think they were using different pliers since the pieces were small.) Anyway, I should have been using the pliers perpendicular to the scored line. Once Phil showed me the error of my ways, things worked much better. Funny how using the tools correctly will do that.

I also was somewhat perplexed about firing. I read many directions on firing and somehow I just kept getting more confused. After successfully cutting many little squares of glass today, I decided to just jump in and fire them. For some reason I remembered that my kiln's manual covered different kinds of firing. Who knew that the information in that manual was the easiest to understand. (At least I found it easy!)

The glass I was using was created for the microwave kiln, but I was quite sure it would fire just fine in the kiln and it did. The manual suggested gluing the glass (didn't need to buy any, just mix up equal parts of white glue and water.) I didn't think I really needed the glue until I bumped the shelf on the way to the kiln. Went back and glued the layers. The manual also said to raise the shelf off the floor of the kiln. (I don't remember reading that anywhere else.... but maybe I did.)

The recommended firing temperature was 1500 degrees. So, at 1500 I checked but nothing much was happening at that point. After that I checked them every 50 degrees and finally had a full fuse at 1675 degrees. Lowered the temperature to 1000 degrees, closed the door and did not peek until the kiln read under 100 degrees.

Sorry that the picture isn't the greatest. (Forgot my camera and had to use my cell phone.) As I said before it doesn't take much to entertain me. Making the cabs was fun (now that I know how to cut glass and how to fire.) And..... I finally wised up and kept notes. I know how many layers are in each piece, what colors I used, and what size the glass was cut. I even made a diagram of the layout. (It's about time.... hopefully I can keep it up.)

Opening the kiln is always like opening a Christmas present. Fusing glass gives me the same thrill (I told you it doesn't take much.) Now I can't wait to use my own cabs in my work.

Monday, April 5, 2010

Back to the books

My last post on the cracking of my dichroic glass brought several appreciated suggestions on firing the glass. When I first started metal clay I read every book I could get my hands on for "how to" information. Recently, I've drifted away from doing that (even though there is still sooooo much I have to learn.)

The variety of firing methods suggested by my readers are as varied as the methods I've found since I "hit" the books again. Lynette fires at 1112F for 30 minutes, then 968F for 2o minutes with no problem. Zoe fires at 1300F for one hour, with no problems.

The very first book I used to teach myself metal clay was CeCe Wire's "Creative Metal Clay Jewelry." Looking back at that book I see that she recommended firing at 1470F for 25-30 minutes, crash cooling to 1000F and leaving it alone until the kiln is room temperature. (But I also see in my handwriting..... PMC3 1110F for 30 min.) Did I fire at that temperature or did I fire at 1470F? (Another important reason to keep good notes...... especially at my age. I celebrated another birthday a few weeks ago!)

This past summer I took a class with Barbara Becker Simon. In my notes from that class, I see that she said glass fuses to metal clay at 1470F if fired for 45 minutes. In her book, she does mention this again, but does make the comment that "the glass may flow slightly and fuse to the metal." (Yeah, this is one time I noticed that happening although it didn't the other times I worked with the glass.) Firing for 45 minutes at 1110-1200F will not fuse the glass to the metal and will need some type of mechanical hold. (That is in my notes too.)

Sherri Haub recommends ramping the kiln at 1500F per hour and firing at 1290F for 10 minutes. At the lower temperature there shouldn't be a need to crash-cool.

Mary Ann Devos also says to ramp up slowly and fire at 1110F for about 45 minutes.

Another thought was that the piece of glass was defective and I'm inclined to think that too. The crack was parallel to the backing which makes me think that maybe that layer was not totally fused. Oh well, I'll still try firing at a lower temperature and see how it goes. Thanks to everyone who commented. I do appreciate your input.