Mom’s making her own glass

>>>Mom’s making her own glass

momfillingplatterHeld an informal workshop in my studio a few weeks ago–enjoyed it very much and my “students” appeared to get a kick out of it as well–and Mom suggested that she would like to do some glasswork, too.

She’s a terrific ceramic artist; some of the pieces she’s thrown for my birthday/Christmas gifts are among the favorites in my collection. Ceramic artists have a pretty ingrained understanding of the effects of heatwork, and we’ve often discussed the differences between ceramics and glass in that respect, so I figured she’d take to it.

momplatterdoneShe did, like a duck to water. She wanted to try a technique I’m working out right now, a frit tint/cast process, to make a platter for a friend’s Christmas present. She chose an oval Bullseye platter mold, which kinda set me thinking. I build casting boxes for my panels out of 3mm clear glass and superglue, with sides that range from about 3/4 inch to 1.5 inches (depending on the effect I’m looking for).

Took a bit of thinking to figure out of how to get a similar wall on an oval without (a) cutting and slumping it or (b) cutting and stacking ovals, which would be ‘way too thick.

What we came up with is at the top of the page. It isn’t the way I’d normally recommend doing a dammed-up oval, but for the tray-filling option it works quite well. And in the end we had a custom oval frit casting tray, one that Mom could fill with her choice of tinted frits.

Just as an aside, for virtually any other kind of thick oval project, I simply run some strips of fiberpaper around the outside of the piece, slightly below the finished level (to allow surface tension to round over the edge without pricklies). Then I use about a gazillion kiln posts and bricks to hold it in place.

As long as you touch evenly and lightly every inch or so around the edges, with enough weight behind it, the paper will stay in place. I’m not sure I’d use this method for more than about a half-inch of glass–the weight of the glass may push the fiber paper around as it’s trying to move. For that, I generally cut an oval of fiber paper that’s a bit bigger than the final size, pin the vertical strip together (with stainless steel pins) and push the oval into the strip circle.

That forces it to take the correct shape, and the excess fiber paper in the oval slides up the sides of the strip, forming an additional dam to keep the glass from seeping out underneath.

It does leave a crease in the edge, but I’m not too concerned about the condition of the edges with any of these methods, since I usually cut or grind them off.

Anyway, the platter came out, I had my favorite waterjet cutter (John Groth) cut off the edges to make a clean oval, and I slumped it today.

momstreakyglassMom then decided she wanted to try making some small plates or trays for Christmas presents, and we headed to Bullseye’s Resource Center to pick out some glass. Unfortunately, the stuff she really liked was regular streaky and ring-mottle stained glass, not fusible.

She wanted a pretty, watercolor effect in her friend’s favorite colors. We headed back home with a sheet of fusible clear/white streaky, she picked out some frit powders she liked, and we made our own “streaky” glass.

Wasn’t difficult–just sifted, flung and sprinkled the powder in random patterns across the glass. What you see here is BE pink, olive green, powder blue, neo lavender (opaque) and a little cobalt blue. It doesn’t show up very well in the photo, but it’s a delicate, airy pattern when you see it in person.

We’ll cut it into squares, edge it with something (haven’t picked that out yet) and probably can get 4-6 small plates and a larger serving dish out of this piece. All in all, a great start.



  1. Dave Jenkins May 6, 2014 at 7:29 am - Reply

    I’m sorry to be so dense, but I’m not getting what’s going on here. If you have an oval mold, can’t you just cut some oval blanks, fuse them together, and slump them? (In the simplest case.)

    What’s the purpose of the little vertical pieces that have been glued to the edge of the oval blank? Are they to keep the frit flowing out and off the base?Did those pieces strike to the deep blue shown in the finished piece?

    Is the whole process to allow you to cut the oval precisely and then maintain that geometry while fusing in the firt?

    Did the water jetter trim the final result perpendicular to the plane of the base?

    Just trying to wrap my head around this, Cynthia – thanks.

    • cynthia May 8, 2014 at 11:22 am - Reply

      Well, it was an improvisation. The idea with the vertical pieces was, indeed to make a barrier that kept the frit from flowing off the base. I could also assemble this in the kiln with dams and fill it up on the kilnshelf, or I could either cut oval blanks and oval rings, then glue or tack-fuse them to make a base, or–if I were going to make a lot of these, just go ahead and build a permanent dam from fiberboard or something.

      However, we were in a hurry and I wanted to accustom Mom to the glasscutter. And it certainly gives the most flexibility.

      I had the flat blank cut with waterjet, trimming off the edges back to the cobalt (that was part of the fritpack). He cut perpendicular to the glass, and then I slumped it in the mold.

      Does that help?

  2. KaCe May 2, 2014 at 2:41 pm - Reply

    When you are doing all the tossing of frit where is the glass? On Thinfire in the kiln? On a work table on thinfire, so you can move it easier? Do you save all the overage frit in a bottle of it’s own for another attempt? Or will the colors muddy up and be no good? Thank you for the link to your blog.

    • cynthia May 2, 2014 at 2:51 pm - Reply

      Well, we didn’t get all that scientific about it. We set the glass on cups on my worktable on an old sheet of newspaper (the cups get it off the table and make it easier to lift). Then we tossed on the frit (and stringer and stuff), took the sheet to the kiln.

      Typically, if I’m not careful about separating the powders, all the excess goes into my “filler” bottle and yep, it gets all jumbled up. If you fire it by itself it will look brown-black, usually, although it can be interesting if the powders are tossed in without mixing–you can get some nice variegation.

      More typically, though, I use the stuff in that jar as filler frit for casting. That’s for the stuff that goes in the back or deep center of the fill, and doesn’t need to be any particular color or transparency–it’s just there to fill out the volume I need.

      I can lay out a stack of newsprint, put the cups down and the base sheet on top, and sift on ONE color/frit size. Then I can move the glass, pick up the first sheet of paper and funnel the frit back into the jar. Then I discard the paper, do another layup on the new paper, and repeat until I’m done. That’s a lot of trouble unless you’re only doing a couple of colors, and with every lift you risk tilting the glass sheet and having some of the frit roll off and contaminate things anyway. (So, mostly, I don’t do that)

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