Slugfest

I really like slugs. More specifically, I really like nudibranchs, the wildly colored, shell-less critters that wend their way through kelp beds, coral formations and sea floors around the world.

In fact, I’ve been making glass in honor of nudibranchs whenever the mood takes me:

So it’s particularly nice to have found a forum completely devoted to the sea slug. Sea Slug Forum is, moreover, a very nicely put-together website, with clean navigation, lots of photos, and an unswerving purpose: Tell the world about the wonders of sea slugs.

Take a look. You, too, might get hung up on slugs.

The glass versions of nudibranchs are fun to make, and a good way to use up scrap glass. I’ve done them in float glass–which makes an interesting white-on-white piece, given float’s extreme tendency to devitrify (i.e., start to crystallize and become not-glass). But mostly I do these with whatever scraps of regular fusing glass I have left over, and spare frit, stringers or powder for color.

Float is a stiffer glass and (at least the stuff I’ve gotten free from broken windows and doors) is extremely prone to devit and can’t take much more than a single firing. I get my best result from at least three separate firings with these things, and at that point the float just about looks like a pile of granulated sugar.

Even with regular fusing glass like Bullseye, I still see some devit by the end of the firing (left). In part, this is because I may use glass that’s already been fused. Mostly, though, it’s because I’m using a pretty rough firing schedule, almost guaranteed to bring out scum, if not full-blown devit.

Scrap-wise, I build them from the leftovers of circle-cutting–the long, thin pieces with the internal curve. I stack them up (can’t find my images of a stack, but when I do, I’ll post) to resemble stars in the kiln, with the thinnest edges curving out. I want a fair amount of mass in the middle, with a lot of irregular, radiating arms.

As I stack, I’ll lay colored scrap or frit on the clear. I’ve got a thing for a particular nudibranch group known as flabinellas (right), which are mostly clear or translucent like glass, with often-iridescent slashes of color. They’re where I got the idea for the nudibranchs, so I like to stick to basing my designs on clear glass to get them as close as possible to their namesakes. I’ll add frit balls or scrap to the very tips of my stars, often in colors or dichroic glass.

Nudibranchs are what I call a hot-fuse project, i.e., the opposite of my normal style (go low and slow with my firing schedule to keep the glass in place, bring it down gently into the mold (or other pieces of glass), and only fuse just enough to get it to stick/flatten/whatever without losing the shape of my carefully cut-and-placed components).

In these, I pretty much go up as fast as I can, to shock the glass, potentially shatter it further into interesting patterns (though it doesn’t often do that), get it to lay down and alter its shape as much as possible. By slightly overheating the glass and keeping the outlying star shapes thin, the glass starts to “dogbone,” i.e., shift to get as close to an even 6mm as possible, throughout. That means areas thinner than 6mm will contract and pull in, areas thicker than that will round over and start to flatten out. It produces soft, sinuous shapes that look more blown than fused.

I generally give these two full-fuses; after the first, I review the result, figure out where needs more color or arms or whatever, and dig out more frit, glass and stringer to fill in. I flip the glass over, add whatever’s needed, and fire again. The flip-over’s usually needed to melt in whatever frit got trapped between glass and shelf. It doesn’t fully fuse, and leaves your glass with a grainy look and a sandpapery feel.

Once I’ve got the pattern I want in the flat glass, I’ll slump it to shape. With smaller pieces, I’ll toss down some used fiber paper and set the glass on top. When the glass softens, I’ll go in (with protective gear and a couple of wooden sticks), pull the glass up by hand, flip it over so it’s now cup-side up, and “freeze” it in place as the air coming into the kiln cools it in place.

Then I close the lid and start the cooling program on my kiln. There’s usually enough residual heat to keep softening the glass, so gravity pretty much removes the artificial shaped look of my kiln manipulations. I let it cool naturally, and it’s done.

That doesn’t work so well for big pieces–the one at the top of this page is about 22 inches tall–so for those I slump over a stainless steel form, well-padded with refractory fiber. I try to keep the shape as organic and random as possible, prop my steel form up on firebrick so that I don’t get a hard delineation where the form meets the kiln shelf (which gives you a very artificial-looking right angle), and carry the fiber blanket all the way down to the shelf.

Caution with this method: You must be careful to let the fiber blanket form a skirt all the way around the steel form, and not overslump the glass. Otherwise, I guarantee that at least one of the nudibranch arms will curve back under the form and trap the mold.

If you DO trap the mold, you can repeat the slump cycle, open the kiln at the hottest part of the firing and pull out the trapping glass arms, then prop them back with kiln furniture. It’s a royal pain to do that, though, and increases the potential for devit.

I use a similar method to make bases for these things, only this time around I let the glass touch the shelf to make stable feet. Then I clean the pieces up, play around with stacking them in different directions, grind the bottoms slightly to make a flat surface for gluing and “cold-fuse” them together.

They’re not great art, they’re not functional in the slightest, but they’re cool to look at and a great way to use up scrap glass. Well worth trying, anyway.

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