Monday, January 24, 2011

To Die For...

I knew that making tiles would require a fair amount of study on my part. I wasn't wrong.

It wasn't the clay work that proved tricky. I have plenty of experience with clay and know how it behaves. Mind you, that doesn't stop a person having to learn the best way to keep a small slab from warping. That's something that clay likes to do under most conditions and figuring out how to keep it from happening has been the work and source of frustration of potters since someone said, "Hey look! If you line a basket with this sticky mud it will hold water!" There are techniques to stop warping and I know a few of them.

But where I had a lot to learn (and still do) is in plaster work. Mixing and pouring a wedging table is not that difficult once you get the math out of the way. But working in smaller quantities is a little trickier. See, the problem is that all plasters come with what is called a "use consistency." It is expressed as a number, and the use consistency of the plaster I have been working with is 70. What that means is that for the strongest possible end product, I have to mix 70 parts water for every 100 parts plaster.

By weight. Go figure. And figure I did. Long and short, I came to the answer by two routes. The first was to take someone's word for it that I needed 2.85 pounds of plaster for each quart of water. The second was to weigh a quart of water and calculate it myself. A quart of water weighs 2 pounds. Dividing 2 by 0.7 gave me...2.85. I'm a believer now. My algebra teachers would be so proud.

All of this is because making tiles first requires me to make a mold. The mold - or in this case the die - is used to stamp a consistent pattern on each tile. if you want to make tiles in any sort of production model, you need to do it this way. Hand carving each tile would take far too long to be practical.

The mold I wanted to make was a die mold. This type of mold is pressed into the clay to create a shape or, in this case, an impression. That meant hand making an original to make the mold from. Remember that tile I thought I'd make for the holiday season? It's a few entries down. I did make the original but ran out of time before I could put tiles into production. So I decided to put that project to next year.

Just as well. The process of learning to make the mold, while moving along nicely, is still a work in progress. But there has been progress! Here is a picture of the original and the die mold that I made from it just this evening:

The original was warped, so this die can't be used for production, but the mold form I made is ready as soon as I have a good, flat original. At least I have the process under control now. It will be full steam ahead very soon.

I have a number of ideas for tile series and will be working on the artwork for them starting next week. For now, I have other issues to concentrate on and concentration is proving difficult as I try to stay warm in the icebox that Maine has become. It happens almost every year at this time, but still it always seems to catch me up a little short.

More soon!

No comments:

Post a Comment