(Crosspost of this LiveJournal entry)

Pictures I took from there workshop are available online here.

:linkusertabalon, :linkuserpanhesekielshiroi, :linkuserjumpy and Eisfuchs got me a birthday present you likely get only once in a lifetime - A voucer for a Glassblowing workshop. No need to mention how bouncy and nuts I was about it. I've been working with glass every now and then since ages. Mostly creating Tiffany- and Leaded-Glass windows pictures. The idea of working with molten glass came to my mind every now and then. Primary in the context of creating small figures, like a lot of people do in the small town called Lauscha (Wikipedia: Lauscha). Lauscha is called "the home town of the glass craftsmanship and the hometown of the bauble". It's located in the middle of Germany in the state Thuringia. I spend sever winter holidays there with relatives and it was always fun.

Anyway! Last Saturday it was my turn to try my skills with molten glass. I visited the glass atelier from Berlin Glass e.V. a small society that offers atelier workspace for rent and public use. Finding the address wasn't a problem. The proper building, in fact, was hard to find - everything looked pretty abandoned. After I spend some minutes wandering around I found the workshop and was, to be honest, a fair bit disapp… surprised. The website of named association was all fancy and I was expecting a huge workspace with a lot of tables and lots of people at work. What I saw was a small (really) hall with the most interesting thing being the main furnace and the glory hole. In fact the only things they have photos from on their website. Well, so the first impression wasn't the best one. But let's not live by impressions but let’s do something.

The Workshop started with a brief introduction to some tools, dos and don'ts when working with glass or being near the furnace. Speaking of the furnace. What an energy consuming monstrosity. It holds 180Kg of glass (which is about 180Ltr.) and consumes around 10kW constantly only to keep the molten glass on a constant temperature of 1610°C (Grad Celsius for the foreign readers). Just calculate the amount of energy in kW/h and money this best requires on a daily basis. And that doesn't even include the amount it needs to create/melt glass. In Germany that's about 60 EUR/day, taking they have a regular contract and none for a business that requires a lot of energy. Also worth mentioning is the heating system itself. It exists of a 3-Phase transformer that transforms the 400V Grid-Voltage down to 36V. The temperature regulation happens by using wave packet modulation. Which means there are Tricas in the control unit that won't cut the waves somewhere in the middle but use full periods. Which, in fact, is the only simple and usable concept in this case. Everything else would feed a mess of distortions back to the grid. Also worth thinking about: mow many Amps are 10kW on each of all three phases with a voltage of 36V? ~160A. Which requires thick cables. Inside, like you see on the photo, there are six heating elements made from special metal that won't oxidize instantly when driven to a temperature near the point of glowing all white. I guess the heating elements are covered themself.

The second impressive instrument was the heating unit called "glory gole". It's basically a huge oven with shutters where you put your workpiece into to heat it up again so you can go on with your work. It uses a mix of pre heated, compressed air and Propane gas for heating. The amount of created heat is about 14kW. The interior is coated with a special concrete that withstands temperatures up to 1800°C and is heated up to the point where it glows almost white. My partner lost a workpiece in it and it instantly melted into the concrete. Funny thing.

You can't imagine the heat. It is incredible. I mean it. You just can't. We had shields in front of both the furnace and the glory hole to shield most of the heat but it was still almost unbearable. It's hard to imagine HOW much heat gets radiated even when the shutter of the furnace is open just about 10cm. I'm not the one that shies away from excessive heat instantly or that can't take some pain but after just 5-8 seconds I couldn't bear it any longer. I had to be very quick when taking more glass from the furnace. I once opened the shutter full to take a photo. I had to take it from 3 meters away. Even two meters was not bearable for more than 20 seconds. What can I say? Both, the 180Kg of molten glass and the special concrete almost glowing white radiate lots of infrared. In the end I was rewarded with a medium sunburn on both arms. And I had already a quite brown skin from all the time I spend in my garden this summer.

For the wise people that think: dude, use clothing with long sleeves: yeah, you're funny! I showed up in clothing suitable for welding. But as soon as I was near the furnace I regret wearing a thick shirt made of cotton. I changed. The Workshop heated up to about 40°C after an hour. Soon I was all soaked and the fabric stuck to the skin which kept me from being agile - which was important.

We had the opportunity to work on two pieces. The first was a multi-colored marble which used small glass shards to color the transparent glass from the furnace. The knowledge to gather from this was to get a feeling (and see) how glass flows, how fast it flows and how to guide the glass into directions. Also how fast glass melts again when being introduced to the glory hole. The colored glass helped a lot understanding. Speaking of understanding: I also tried something else when it comes to learning new things. Usually, I'm the first to try something in a group while everyone else is still unsure. This time I forced myself to be the last. That wasn't easy but I could already learn a lot about the medium glass by watching the mistakes others make and how the material behaves. The most important thing: don't add pressure to glass (most of the time) but just let it form itself by gravity.

The second piece we should create was a drinking glass, which was the piece where we should learn how to blow glass. Like before, I preferred to watch. Which was a good thing, because my piece started to turn out the way it should. I started with a perfect small bubble of glass which I was able to expand further to a small tube that got cut open along the way. At some point in the process of forming the glass a second hand is required and that's where the workpiece got partly damaged. My partner turned the hot glass too slow (or I forgot to tell him 'go faster') while I was blowing and further expanding it. The almost perfect tube became aslant and I wasn't able to correct it because the glass was prone to become too thing on one side. I've to admit that I'm still a bit grumpy about. I'm a perfectionist and I was all happy about the good work I did. But well, maybe I'm going to ask how much they charge only for the drinking glass project itself. I know I can do it and I want to prove it to myself.

I wish I had taken more pictures but - like you may guess - hot glass hates waiting. It either deforms or gets cold.

So... in the end: I'm still a bit disappointed about the workshop for I thought I'm able to take some more impressions and ideas how stuff work along back home. For all other things: yes, so worth it! Our tutor knew his craft well and even when the workshop was a tad too short for my linking (and endurance... hell... when I'm already all wet nothing keeps me from going on! If you don't sweat and get all dirty it's no fun!). It was an awesome experience and I took a good bunch of basic knowledge and experience with me.

Thank so you soooo much folks for this present! That something I won't forget about for a long, long time! :)