Tuesday, August 25, 2015

Bhakail Commons

Me, Suba, and Aibilin at Bhakail Commons

This day didn't start out as a demo/teaching day, however, once people saw Aibilin and I making beads, they came over to watch, ask questions, and a few even asked to make beads themselves.  If you bring your torch, they will come to make beads!

We also used this opportunity to give Aibilin practice teaching. Teaching someone how to teach is an interesting thing to do. We started out by having her watch me (which she has been doing for some time already). She then taught a few people, and I watched and provided some commentary to her about what I might have done differently and why. This was also a great opportunity for me to learn from her. Aibilin has watched others teach (most recently at Pennsic), and a few of the things she was saying during her time instructing people are ideas that I should include as a regular part of my lesson!

Monday, August 24, 2015

Period Bead Making at Pennsic

At Pennsic this year I helped Bruni make a clay bead furnace in the volcano style (See Dudly Giberson's "Volcano Dream" article)  during peace we. Together with Aibhilin we fired it and mad a few beads the Sunday of war week.



Constructing the Furnace
In this experiment we were building off of our previous experiment where we determined that a mixture of sand, refractory clay, and regular clay worked best. However, we also tried a few things differently this time:

1. We used grog instead of refractory clay. Reading volumes 4 & 5 of the actual Ribe excavation reports  (not the summary by Mogens Bencard published on the DARC company's website which we used for our last experiment) I did not see the word refractory clay used. Grog, however, was mentioned in the actual report from Ribe as being found in some of the bead workshop hearths (Sode 2004). Grog is basically ground up/crushed pieces of already fired clay  (Piepenbrg 432). Because these ground up pieces of grog have been pre-shrunk by firing, it helps prevent warping and cracking of the furnace just as sand does (Piepenburg 20).

2. We increased the amount of sand used. Bruni found a video about 18th century bread ovens where the builder used a high proportion of sand in their mixture. The author of the video noted that more sand than clay would help reduce the shrinkage and cracking in the oven (4:00).  

Note: this video also described using hay to add strength to the oven. This is something we plan to look into doing in a future experiment. Hay, being an organic material would likely not have been preserved at the Ribe workshop if it was used there.   

While it may seem strange to use a video of an 18th century bread oven as a source for a Viking bead furnace, the basic principles involved in building a furnace/oven seem to be similar across a wide time period. The author of this video noted that most ancient cultures have some variant of this type of oven, and that there are pictures of this type of oven from the Middle Ages. As I noted in the write up from our last experiment, the excavations at Ribe don't give us much detail about what made up the bead furnaces (just that clay and grog was used), so we need to experiment  to see what proportions work best in our mixture.  Modern archaeologists do something similar when they look to people today that make beads using a more traditional clay furnace (Sode 2003).

We built the furnace using 2 parts sand, 1 part grog, and 1 part stoneware clay. Due to time constraints, we were not able to take the time to build it quite as high as we would have liked, so future attempts will likely be a bit taller. We added in notches in the side for the mandrel to rest on as in Volcano Dream article. We let it rest for 3 days to dry before firing.

Firing the Furnace
Working in the furnace.
Once we managed to get the fire to catch (which took a bit), the furnace quickly got up to a temperature where we were able to make two beads (using the 120 coe glass).

We also took a video of us making a bead with our furnace!

By the second attempt at making a bead, the coals had gotten very low in the furnace, and we would have needed to add more and wait a bit for them to get up to temperature, to continue. If we had added more coals, we likely could have made more beads. Unfortunately, it was close to 11 by this time, and we had to stop so we could let the furnace cool down and then go to bed!  Pennsic, due to scheduling constraints, may not be the best place for our experiments.

Bead made in the furnace.

Condition of the Furnace after Firing Some thin cracks did develop in the furnace by the end of our working session with it. However, we were pleased overall with how the furnace stood up. None of the cracks that developed seemed to go all the way through to the inside of the furnace, or were large enough to cause us to loose heat while working.

Note Since sand and grog function similarly, maybe we just want to use grog in the future? Sand was found at Ribe, but it was described only as being layered between workshop levels (possibly spread during the annual cleaning of the site) not as being mixed in with the workshop hearths themselves (Sode 2004). We have also just found a few modern books and online forums on pottery which state that at high temperatures the sand in a clay mixture will start to crack due to the "quartz inversion of silica" (Piepenburg 20).

Crack in the furnace after firing.

This is likely the last experiment we will conduct this year. At Pennsic I was able to talk to Tinker from the mid (who was one of the people I first saw doing these experiments) and and get the names of some interesting books, and other resources (including notes on her own experiments). Much reading will happen, and then we will have new experiments hopefully in the Spring.

Citations:

--Bencard, Mogens. (n.d.) Viking Age Crafts in Ribe: A summary.   Translated by Michaela 
--Gibbion. Retrieved from: http://www.darkcompany.ca/articles/glasperlen.php
--Giberson, D. (1995). The Volcano Dream. The Glass Art Society Journal. pp. 77-84.
--Piepensburg, R. (1996). The Spirit of Clay. Pebble Press

--Sode, (2003). Viking Age Glass Beads from Ribe, Denmark, In Light of the Ethnographic Research, In. Ian C. Glover, et. al. Ornaments from the Past, Bead Studies After Beck. London: Bead Study Trust
--Sode, Torben (2004). “Glass Bead Making Technology.” In Mogens Bencard, Aino Kann Rasmussen and Helge Brinch Madsen. Ribe Excavations 1970-76. vol 5. Jutland Archaeological Society.  p. 82-102.  Note, I also looked at vol. 4 from the Ribe Excavations. This volume covered specifically the research done on the stratography of the site (the layers of deposit that make up the site). 

Thursday, August 20, 2015

Grave 50 Portway Andover

Below is a picture of a bead string (grave 50) from the  Portway Andover excavation report.  This is the third bead string I have recreated from that report, and I completed this project for the Artifacts of a Life event at the end of September.

Historic Glass Beads

This bead string, (which is interpreted as a bracelet) had 25 glass beads, 4 amber beads (which I recreated in amber colored glass), one fragmentary metal bead (which I did not replicate), and two Roman coins (small copper colored store bought medallions were used as a substitute).

My recreation
Thoughts on my recreation process

None of the beads on this string were very advanced, so technically, this was a relatively easy bead string for me to recreate. Any difficulties I had in recreating this bead string came about because some of the beads had uneven shapes or mistakes in their design, which I tried to replicate this time around as exactly as I could manage.

Replicating beads with specific mistakes actually takes me a good bit more time than replicating perfect beads of the same design, because I have to observe the historic bead a bit more closely to figure out how to make the same mistake found on the historic bead. It also takes the same amount of technical skill to replicate a specific mistake on a bead.

If I was talking with a newer bead maker who was interested in reproducing this bead string, I would encourage that person to attempt to make the beads as best they could, and not to worry about replicating a specific mistake. But, if they did make a mistake on a bead, I would tell that person to keep those beads with mistakes in the final project. In that way, I think a bead string would come to have the "feel" of the original, with its combination of beads with imperfections, and more perfectly executed beads.

Mistake Beads
To the right are examples of my "mistake" beads, beads which did not make it into the final bracelet. In most cases, this I rejected these beads because they did not match the extant necklace well enough, not because my overall technique was poor. I'll likely keep at least a few of these beads  to be given away later.  Some of the reasons these beads were rejected include
--wrong color: I was trying to mix my own transparent light brown for one of the beads, and it came out too dark
--wrong shape: I didn't notice that the documentation provided a better view of the bead until after I created it.
--wrong size: I made the bead a bit too big the first time
--wrong decoration pattern:  I included one too many or too few waves on a few of the beads, either by accident, or because I did not look closely enough at the historic bead the first time. In one case, I was also trying to replicate a bead with a very sloppy decorative technique, and gave it a few tries to see which one looked most like the period bead.
--large air bubbles in the bead: This is the one actual technique "mistake" that I made during this recreation project. I trapped several large air bubbles in one of the beads. This is a problem, because air bubbles increase the risk of bead breakage.

Wednesday, August 19, 2015

Pennsic Recap

This Pennsic was a very A&S filled year!

1. A&S War Point
I never thought that I would get to participate in a war point, so I was very happy to have had the opportunity to be involved in this one! Happily the East/Mid won the A&S point, and I came in the top three artisans on the East/Mid side. A very good day and a great experience. I hope the war point happens again next year.

Article from the EK Gazette about the war point with pictures

2. A&S Display


3. Artisan's Village
I participated in both the peace week and war week glass Artisan's Village again this year.

4. Classes
Of the 3 classes I taught, all seemed to go well. I taught Recreating Historic Beads as a Beginner for the second time this year. I fixed an issue from last year, where I had too many separate handouts, something with made the class a little disjointed. I reworked my handouts so I only had 3 this year, and the flow of the class felt better.

The class on Reproducing Glass Beads Using Archaeological Reports was an expansion of a previous class. I added in information about how to find these resources based on feedback from my peer, and it was exactly what the class needed, I think. The attendees seemed to find value in it, and I know at least two people who I talked to came because they were having research problems with a specific project they were doing.

The last class Recreating Anglo-Saxon Glass Beads was one I taught for the first time, and it was my first hands on class.  The 45 minute lecture at the start on Anglo-Saxon beads was well received, and made the class useful for those who were not able to secure one of the hands on spaces. It was nice to be able to use the research and documentation I conducted for A&S competitions to teach a class. However, I learned the most from teaching the hands on portion of the class 1) people of widely varying skill levels will attend this class. I had people who just learned to make a bead at Pennsic and people who were intermediate bead makers both in the class. I was prepared for varying skill levels, but I didn't think I'd get brand new bead makers in the class! 2) Get extra helpers or a co-teacher! There ended up being 8 set ups for people to use to make beads, which was more than I thought I would have. This was great, as more people could take the hands on part of the class, but it also meant that I had to help more people at the same time. Luckily, Erica was there and graciously agreed to help, as did another advanced glass bead maker who attended the class. 3) I think that next time I will choose just a few few beads (each of a different skill level) for people to reproduce, rather than letting them choose any bead from Brugmann's book to work on.  I will also demo those beads before letting people play. This way I can focus a bit more on teaching people how to really look at the bead, considering its shape, color, measurements, etc. before recreating it. I talked about this a bit during the lecture, but did not demo it.

Tuesday, August 11, 2015

Bead Furnace Experiments: Clay Mixtures

In May, Bruni, assisted by Aibilin and I, built several small open clay bead furnaces. We were attempting to make something similar to the less period firebrick furnaces we have been working with, but this time using a more period appropriate building material for our furnace.

The excavations at Ribe found flat hearths made of clay. However, the primary source about Ribe we read (cited below) did not give us much detail about the type of clay used. However, the article we read did note that refractory clay was found mixed in with the clay at at least one of hearths at Ribe.

Because not much information was available from the Ribe excavation about what material the bead furnaces were made from, the purpose of this experiment was primarily to test a few different combinations of building materials.

Two of the small bead fireplaces we made. Labels noting what materials we made the fireplace are visible carved into the clay in the picture.

We made small open fireplaces out of two different types of clay, ball clay (recomended by the owner of the ceramics store for this project) and stoneware clay, a clay that Bruni was familiar with from her work with ceramics.  We also tried mixing the ball and stoneware clay each with the refractory clay that was mentioned in the article about Ribe. Refractory (or Fire) clay is a type of clay that is more heat resistant than other clays. It is what the firebrick we used in our earlier experiments was made from. Finally, we also added sand to the mixture. Where we mixed more than one type of material into the clay used a simple 1 to 1 ratio of materials.

Note: we may want to try earthenware clay in the future
http://pottery.about.com/od/understandclays/tp/claytypes.htm

The addition of sand was recommended by the owner of the clay shop where we bought our materials. We had also seen sand being added to clay in other period and post period furnace/oven constructions. 

The sand is useful and important for a particular reason. When we were reading more about ceramics we found the following quote about primitive ceramics:  "objects made of a coarse, open body with plenty of large particles in the clay will tolerate more variations of thickness and fire with less risk" than an object made from finer clay particles and a thinner more uniform walls (Philip Rawson, Ceramics, 25). Later on, Rawson goes on to discuss more "primitive ceramics" which are put in direct contact with open fire, and which tend to be coarse/open bodied with big particles as a result (47). As our bead furnace would not be able to be fired in a kiln, we needed to find a combinations of building materials that could stand being exposed to direct fire.  As Bruni, who has taken many ceramics classes at U Penn, noted, when the water in clay is heated quickly as the kiln is being used, it will turn into water vapor. That vapor expands, and if it is trapped in the clay, it and can cause the furnace to explode when it is used. If the furnace is dried fully before use , this will be less likely to happen. However,  as the clay furnace dries, it will also shrink as it looses water, which can cause the furnace to crack even before it is used. The sand helps prevent the furnace from shrinking as much as the clay looses water and dries. It also allows the water an easier path of escape as it heats if it is not fully dry before use.

We built the clay fireplaces one weekend, and let them dry until the next weekend we all had free to play with them (about a month later). The goal was to stress test them, to fire them quickly and see which one either did not break, or lasted the longest.  We could then use this mixture to build bigger volcano shaped bead furnaces, or beehive furnaces. We did not time precisely how long each fireplace lasted, but we were able to make general observations about how long each fireplace worked before it started cracking. The small fireplace made of just ball clay cracked before  reaching a temperature sufficient to melt the 120 COE glass and we couldn't even start to make beads with it. The one made of only stoneware clay lasted a bit longer after we started a fire in it. When refractory clay was added to the mix, the fireplaces seemed to resist better. They seemed more able to withstand the heat, and we could use them for a time, but there was still some major cracking. 


Example of one of our clay fireplaces that cracked.
Overall the fireplaces with the sand and refractory clay both mixed in with the ball or stoneware clay worked the best by far; there was only minimal cracking in those fireplaces and we were able to use them to make beads using the softer 120 COE glass. We had to stop our experiments before those fireplaces failed due to incoming rain."Clearly the sand was important to the mixture for the reasons stated above.


Using one of the fireplaces to make beads from a glass rod.

Using one of the fireplaces to make beads by winding the class from a punty.


Source: Bencard, Mogens. (n.d.) Viking Age Crafts in Ribe: A summary.   Translated by MichaelaGibbion. Retrieved from: http://www.darkcompany.ca/articles/glasperlen.php

Thursday, July 16, 2015

Grave 19 Portway Andover

This small bead string is from Grave 19 of the Portway, Andover Anglo-Saxon Cemetary.


I completed a recreation of the above small bead string (likely a bracelet) over the course of 3 evenings. It took 2 evenings to make the beads, and 1 to remake a few beads that I was not fully happy with. I was originally not very excited about this project. I primarily made it to make sure that I would have enough items to enter for the Artifacts of a Life event, the event I created the larger necklace from Portway for. The technical level of this bead string is very low for me (no decoration, minimal shaping), and I didn't think it all that pretty to begin with. However, I'm glad that I did recreate this string, because actually seeing my recreation transformed how I thought about the bead string.


In person, this small bead string is quite adorable. Maybe my feelings changed because I could actually hold the string, instead of just looking at it on the page. Maybe it's the fact that a newly created bead string is so much more shiny than the historic one, which had been in the ground for centuries. Having the bead string in front of me also helped to emphasize just how symmetrical it was, especially towards the center of the string, and my modern eye really appreciates this symmetry. The order of the beads in the grave was mostly preserved, so this bead string is a likely example of the aesthetics under which Anglo-Saxons strung their beads.  The symmetry is not perfect, but it is quite obviously there, which is something I have found, to a greater or lesser extent, with most of the Anglo-Saxon bead strings I have recreated.  The distinction between light and dark beads is also very evident (another idea which is prevalent in the Anglo-Saxon aesthetic). There are many dark blue/black beads, with a fewer lighter white/red beads placed at regular intervals among the darker beads.

A few technical thoughts about my reproduction:
-The beads were made to match the size of the historic beads to within a couple of millimeters size.
-I forgot to try to match bead perforation sizes with the historic necklace, so that aspect of the recreation is not as accurate. However its not something that is very evident when the necklace is displayed/worn.
-A few of the beads (the white ones) were simply not listed in the description of the grave. The necklace is described as being made of "glass and other beads." I think these white beads are not glass (maybe stone?) but I've recreated them here as glass beads because that is the material I work with.
-I was not happy with my first attempt at recreating the bicone white bead, because my bicone was much straighter and more precise than the original. It just didn't look right when strung. So, I tried again, this time making it a bit rounder and it worked out well.  I also burned the glass slightly the first time, so I was a bit more careful the second time and turned down my flame and tried not to overwork the bead.


The bead on the bottom is my first attempt. The top bead is my second attempt.

-The same thing mentioned above happened for the largest black bead in the string. The edges and lines of my first recreated bead were too straight, so I tried again it, rounding the bead out slightly more the second time
-Finally, bead #25 is an odd one. It has red glass at the core, and then clear glass over-top, but it is not described in the report as an "encased" bead, and it's very unevenly made. The authors of the report make reference to a "swirl technique" which was referenced in Beck's bead classification from 1927, so I've ILL'ed that book to learn more.

Tuesday, July 7, 2015

Bead Kiln- playing with stringer (part 2)

In my last blog post I talked about how I tried to do stringer work with the firebrick kiln. I noted that the method I used was from a YouTube video created by a French reenactment group, but how a slightly different method was proposed by one of my scholarly articles that I wanted to try. Below is a review of the information from the scholarly article, and then my thoughts about my attempt to use this method.

From my last blog post: One of my sources, archeologists Tine Gam, has done some experimental archeology herself, and she proposes a slightly different method.... Gam thinks that the beads were made by drawing out a thread of glass from the pontil using tweasers, breaking off the tweaser marks (creating glass waste) and then melting the thread onto the bead. Moving the bead back and forth  would help create the zig-zag pattern. The image below is from the article by Gam.

 

I tried this method, and overall I have to say that it did not seem to work as well as the previous method tried. 

First, it was hard to pull a long even stringer from the blob of glass on the pontil. Perhaps the blob of glass on the pontil needs to be heated more before it is pulled, and either I removed the glass blob too soon, or the furnace is not getting things hot enough as it is curently designed? You can see the awkward looking stringer I pulled below.


It was relatively easy to snap off the end of the stringer as described in Gam's article to get a clean point after pulling it with the pliers. It helped to dip the pliers in water and shock the glass. The piece of glass I'm holding in the pliers below also looks very much like some of the glass waste found at Ribe and described by Gam in her article.


When I started trying to work with the small stringer, I noticed that as I was applying the design I would use up the  stringer I pulled and still not be finished creating my design. Perhaps in the past they pulled longer stringers, but, if so, how do you fit a long stringer  in the kiln easily if it is a closed kiln with a small opening---pull the stringer in the kiln itself? Also, because the furnace does not have one pin point source of heat, and you are sticking the entire stringer into a hot kiln, more than just the tip of the stringer ended up softening, making this method feel a bit more awkward to use.



Using the other method from the you tube video still seems to make more sense to me based on my very limited experience. In that method, the design was basically trailed out from a soft glob of glass, and how the artisan pulled the glass trail would influence the shape/size of the line decoration. More experiment with both methods is needed.

***
Finally, some thoughts on the kiln design for this workshop day. This time around I tried adding firebricks around the open fireplace to create more of a closed design. The goal was to create a hotter fire,  but I'm not sure it helped much, as I did not notice that it was much easier/faster to make a basic wound bead. Maybe I could not get the kiln closed enough, or maybe, as Alesone pointed out, it was too small (and held to few coals) to get truly hot. However, I did find that this time I had a bit more trouble keeping my base bead (and the stringer) at the temperature I wanted it. They would get either too hot, or not hot enough to work with. Both of these issues are ones beginner bedmakers have, so perhaps this is a case of me needing more practice using the period fire source. Also, perhaps trying to create a covered firebrick kiln altered things just enough to cause me trouble after I had practiced on the open firebrick kiln.

Its also very worth nothing that winding glass onto a bead requires that the glass and mandrel be held in a slightly different way than when doing modern lampworking or when over an open fire.  This was an adjustment I had to figure out as I was working, using the above mentioned YouTube video as a guide. The first time I tried to work as I normally did, it felt very awkward. You can see from the picture below the awkward angle created when I tried to apply glass to the mandrel in the usual way.


However, using glass on a pontil or a small piece of glass held in angled hemostats, I was able to get the correct angle for adding the glass to the mandrel in a closed kiln. The glass needs to come off the rod/pontil sideways and the mandrel is held parallel/not perpendicular to the tool holding the glass.



Note: Thanks to Decklan for his help during this workshop session! He helped me start the fire, build the kiln, and kept the bellows going.  Could not have done it without him:) Melchior also helped by taking a turn at the bellows, so my thanks to him as well!

Added 9/11: Below is a link to a video of me working with stringer as discussed above. Thanks to bruni for thinking to take video.