I have a lot of glass to grind and polish. I've let the number of pieces build up over the fall as I just couldn't bring myself to slog through it. I finally had to face the daunting task. I've blogged about the type of pieces I'm doing in a previous entry, and I've also talked about the "joy" of coldworking. I don't mind doing it, I just should have done a few pieces at a time and not built up such a backlog.
Above is a picture of the mad genius busily grinding away. Actually, this is the final polishing step. I've already taken the piece to the wet saw to cut the top flat, through loose grits of 80, 220, and 400, and a pre-polish on that green wheel. The green pre-polish wheel is similar to using pumice, but not as messy. The white hard felt wheel is for cerium, which gives the final high gloss polish. It's pretty messy. I really like these Polpur wheels, but I don't think I'll be using them on these particular pieces. The lips of the glass vessels tend to eat away the surface pretty quickly. I don't have that problem on larger surfaces. I've probably lost an inch in diameter on that green wheel.
This polishing machine is hand built from parts. The main piece is a dual arbor I got from HIS Glassworks. The rest I either built by hand or through various trips to Grainger's. It works quite well, all things considered.
Here is a closer look at the polishing step. One thing I learned, don't let the cerium dry on the surface of these pieces. The surfaces are highly textured and once the cerium dries, its pretty hard to get off. I have three pieces sitting in the sink right now trying to dissolve some of it, or at least loosen it up enough to scrub it off with a stiff brush!
This piece combines optical crystal glass, the clear part, and a slab of a Bullseye casting billet glass. I made this during the same time as the "Bird" sculpture. This piece is quite interesting. It's about 6" high, 4" wide, and ranges from about 1" to 1.5" thick. The two glasses were glued together with a glue called "Hxtal" which is an epoxy that is able to be ground and polished much like the glass. In this piece the amber glass started out as slab about 1" wide.
The optical crystal slab represented the rest of the piece, about 5" wide. The two slabs were glued together and then ground and polished. The blank was a rectangular slab but I ground it with a reverse twist. This means that the top twists one way and the bottom twists the opposite direction. This isn't easy and you need to develop a rhythm when grinding to keep the twist uniform and, probably more importantly, not lose control over the piece. I also sloped the front top face to provide even more visual interest. The end result looks like a pillow that has been fluffed and placed on a bed.
The pictures are even more interesting in some respects as the capture some of what you see, and some things you don't notice when looking at the sculpture directly. For instance, the picture above looks like the piece comes to a point on the bottom, and yet the bottom is actually flat and the piece stands up perfectly fine. The picture below it looks as if the bottom is rounded.
Finally, note the amber color and how its looks like it is all throughout the piece. In fact, the amber is just along the left edge and the highly polished crystal is reflecting and refracting throughout the piece giving it a different look depending and where you view it from.
I owe a lot to the instructor, Martin Rosol, who taught the coldworking course at Corning that I attended. He showed me the possibilities of introducing complexity in a piece by utilizing the optical nature of the glass itself.
Sometimes simpler is more complex and interesting.
I make hand-blown glass marbles, which I've blogged a little bit about previously. I'm pretty good at it, but in order to be GREAT, you have to make quite a few. Unfortunately, I don't have the energy or time to practice enough to be great, so I'll settle for good enough. Sometimes I make a marble that is great in it's color, pattern, or something that says this one could have been great, but it isn't quite round or has some "skudge" on the surface. That's where cold working the marble comes into play.
A marble, to be great in my mind, not only has to have a great interior, but also be perfectly spherical. A marble is just a fancy name for glass sphere! I priced out sphere polishing machines that are normally used in lapidary (stone and gem) working. $2000 and up just isn't in my price range. Therefore I do what I usually do, figure that I can make one myself. How hard could it be? A few hours on the net and I saw that others had done similar things. I took the best of what I found, thought about it, and then proceeded to design my own. The video below shows the results.
I was absolutely astonished that it works. I really was a disbeliever in myself. This is less than $50 in parts. The only thing I bought were surplus gear motors at $7 each. The rest of the stuff I had around the workshop. I had the hinges, some extra T-Track, and the on/off switch. I've purchased a collection of pipe fittings and couplers from the big box hardware aisle. There is a whole story that can (and will) be written about what I've learned. The grit feed is absolutely genius. I didn't invent it, but think I've taken a couple of things I saw and incorporated it into a better approach. The grit is suspended in anti-freeze rather than water. This does two things, first it makes the solution more viscous and the grit doesn't come out of solution and sink to the bottom of the cup. Second, water would make parts rust, not good.
I've done a lot of testing, and the results are spectacular. The first marble I did was an early clear sphere that clearly wasn't a sphere. It was pretty squished. Ten minutes at 80 grit and the thing was perfectly round. Un-freaking-believable. It's pretty messy, but cold working glass usually is.
Someday I'll take a series of before, during, after pictures to post. If I could only remember to do it.
