Sunday, April 22, 2007

This Got Me to Thinking.....

It started with beads.

I need some one inch transparent beads for a pair of ray guns. Fumbling through the internet, I finally found a site with beads that almost met my needs; they were made of resin.

This got me to thinking. I've had friends that have cast resin. I could make some molds, and just cast the beads that I need.

I ran some searches on how to cast resin. It looks easy, and wouldn't cost too much. The trickiest bit would be creating the mold.

This got me to thinking. If I'm going to go to all of the trouble to make molds for casting, perhaps I could cast more parts for the rayguns, like handles, sites, triggers, and finny bits. In fact, I could use found objects to help create molds, cast the rayguns in multiple pieces, then join everything together.

One interesting technique is called 'cold casting'. Metal powders are mixed with resin, and poured into a mold to coat the interior. The rest of the mold is filled with foam, resin, or resin mixed with iron or lead shot. The effect is to look like a metal casting, until you touch it. I know that there is an extension to this technique, which involves sand blasting the surface of the finished piece to erode the resin and expose the powdered metal. The metal can then be burnished, which joins the metal particles.

This got me to thinking. I already have gas fired kilns, and equipment like tongs and gloves to use when handling orange hot pottery. If I was going to make molds to cast resins, and wanted to make pieces that looked like metal, how much harder would it be to just melt metal and pour it into molds?

Surfed the web. Looked up 'brass casting', and ran across an interesting site.

So, now I want to scavenge scrap aluminum and brass from the neighborhood on trash day, and melt it into ingots using recovered cooking oil discarded from restaurants, then recast the metal as rockets, dragons, and rayguns.

Thursday, April 19, 2007

Learning To Reason With Two Monks

I took a training course at work a number of years ago.

The class was on creative thinking, or left brained thinking, or problem solving.

The point was to try to get the students to approach problems in a different manner.

At one point, the instructor posed the following problem, and then moved along with the lesson without providing an answer:

"At dawn, a monk stands on a path at the base of a mountain. The path is only wide enough for one person at a time. As the sun rises, the monk starts moving along the path. Sometimes he walks, sometimes he runs, sometimes he kneels and prays. As the sun sets, he reaches the monastery at the end of the path at the top of the mountain.
The next morning, at dawn, he stands at the top of the same path, but facing down the mountain. As the sun rises, he starts to move down the path. Sometimes he walks, sometimes he runs, sometimes he kneels and prays. As the sun sets, he reaches the same spot where he had started the day before.

Prove that there is a placed on the path that the monk stood in the exact same spot at exactly the same time on both days."

Tuesday, April 17, 2007

Projects Projects Projects

  • We've received informal confirmation that both Julie and I are accepted to both the Comic-Con and Dragon*Con art shows.
  • I have one rocket currently in the works, which is a reconstruction of the first rocket that I ever made, back in Georgia. I now need to start a few more. I also need to refire the Luther Burbank and the Clipper rockets.
  • There are four rayguns in the works, two pairs.
    • The first pair started as a small set of candlesticks, and I have the design worked out in my notebook. There are a few parts that I need to acquire, essentially clear beads, somewhere between an inch to an inch and a quarter in diameter. I want polycarbonate, but will settle for acrylic (glass breaks too easily). I would like to get red/blue/green/or amber. The closest match so far is a ball lamp at Wallmart, which has four pink beads on it. These will be small enough to fit into some of the hardwood cigar boxes that I have acquired.
    • The second pair started as brass wall sconces. I need to cut them down a bit, and then torch them back together. The new seams will be disguised by how I mount the handles.
    • There is a big, community garage sale this weekend in one of the nearby developments. This was the same sale that, years ago, I got the original set of wall sconces to make my first pair of ray guns. I am hoping that there will be enough eclectic stuff to allow me to finish the ones that I am working on now, or maybe inspire another pair.
  • My friend Laura and her fiance Bill are getting married on Memorial Day, and I am doing a hundred tiles for favors at the reception. The tile will have a cobalt blue image of the mansion that the are getting married, with names, locations, and dates above and below the image. I created a quick sim of the artwork using MSPaint and wotnot, but need to redo the artwork in CorelDraw so I can size the text properly and burn the silkscreen templates.
  • Working around the kitchen, trying to finish the base molding. There are only a few more pieces to cut and stain, and then it will be finished (after years and years of waiting). We had kicked around the idea of replacing our basement door with one with a window in it, to allow more light into the basement, but finally decided to just finish the project.

Friday, April 13, 2007

Cracking the Kiln

We cracked the kiln last Sunday.

There had been little reduction, most of the glazes never matured, and almost all of my bowls had cracks in them.

I attribute the cracking to the bowls being bisque fired ten years ago, and then following us around for several moves. They probably had hairline cracks before we glazed them.

Two bowls were saved, one that Steph laid claim to, and is now in her room, and the other is a slightly heat warped mixing bowl.

We will try again sometime soon.

The rocket that I threw is dried out, wrapped in a towel in a box down in the studio.

I took yesterday off as a floating holiday from work (forty-sixth anniversary of first man in space), and today as a vacation day.

I'm planning to work on a raygun today. First stop will be to go to a bead store on the White Horse Pike (one of the local roads that goes back to colonial times) to see if they have any large beads that I can incorporate into the pieces).

Saturday, April 07, 2007

Falling Cones

Well, we tried to fire Monstro last weekend.

We started at nine in the morning, and Ronnie threw in the towel at ten at night. She got the kiln up to two thousand degrees, and there it stalled, bellowing flame and soot.

She called the manufacturer of the kiln, Olympic, and talked to them for a bit, and also brought in the gas company.

The first problem was that the kiln still had the natural gas orifices installed, instead of the propane set that I had. Now, I thought that I had swapped them out, before Steph was born, when we had the kiln sitting on the pad next to our house in Phoenix (a.k.a., The Ranch). We had had a studio added as a bonus room to the side of the garage, and were planning to get a propane tank to hook up.

Propane is more energetic than natural gas, so the orifices have smaller holes.

The other problem was that the kiln had been loaded incorrectly. Julie and Ronnie unloaded the kiln, and then reloaded with gaps between the sets of shelves, and rotated the shelves ninety degrees between levels. This is to force the hot gases to circulate more, and to help temperatures even out in the kiln.

We started at nine this morning. Every half hour, we would use a pyrometer to measure the temperature at the top and bottom of the kiln. We would then tweek the gas up a bit. Early on in the firing, we had a three hundred degree difference in top and bottom. We had the kiln climbing at about two hundred degrees every half hour, when, on one tweek, the kiln stalled, and we wondered whether we had given it too much gas. Too much gas is as bad as not enough, and the kiln stalls.

We backed the gas off a hair (there is a single valve that rotates about ninety degrees to control the inflow of gas to the kiln. There are four burners, with an autoignition ring, and a small thermocouple that shuts off the gas if all flames go out for some reason), gained another hundred degrees, then stalled again. Each time the kiln would stall, the temperature at the bottom of the kiln would creep up a little more, so the thermal gap between top and bottom was slowly closing. We then cracked the valve a little wider, and got it to climb again.

Ronnie had loaded three pyrometric cones into a cone pack (a bit of clay to hold the cones up. Ronnie's look like little Viking long boats with three masts). She uses a seven, a nine, and a ten. As temperatures climbed in the kiln, the cone seven would start to bend. A little later the nine would go, and finally the ten. When the tip of the ten touches the bent over cone nine, then the firing would be complete.

The inside of the kiln is really hot, over twenty-two hundred and fifty degrees at the end of the firing cycle. Everything in the kiln is glowing with a yellow-orange heat, and it is difficult to see the cones through the peeps in the kiln, because there is nearly no contrast between pots, kiln interior, cones, and flames. We squinted and stared a lot. Julie loaned us her darkest sunglasses out of the car to cut down on the glare.

After cone seven fell (bent over until its tip touched), we started monitoring the cones and temperature every fifteen minutes. As the tip of nine started to bend, we covered the opening in the lid of the kiln with a piece of broken kiln shelf. This is called 'damping the kiln'. Damping cuts down the gas flow through the kiln. A shaft of flames comes out, which is caused by insufficient oxygen in the kiln for full combustion, so the remaining fuel is burning outside of the kiln. The atmosphere in the kiln is in a state of reduction, and is pulling oxygen from anywhere it can, including the melted glazes on the pottery. This is what shifts a copper glaze from green to red.

A side effect of damping is that the bottom of the kiln starts to close the temperature gap with the top.

The whole kiln got within fifty degrees top to bottom, as the final cone (ten) fell. We shut off the gas, closed the damper, did a quick victory dance, then all went home. It took ten hours for the firing, but we think that we can shave a couple of hours off of that next time by turning the gas up quicker. We now need to wait at least twenty-four hours before cracking the kiln open.


I threw a rocket today.