Medieval Oil Lamp Part Four: Polishing With Pumice

Using the pumice stone has been an interesting experiment!

Polishing materials of the medieval period include bone, wood, horn and some metals, such as copper. These were used chiefly in the the polishing of gemstones. Tenth century Islamic jewelers were grinding up poor quality diamonds for use as a polishing compound. Larger projects, such as arms and armour, employed the use of a bow lathe and in the Scandinavian countries, walrus tusk as the polishing surface.

Below are the two pumice stones I used (toothbrush for scale). 

Wikipedia tells us that pumice is "...a volcanic rock that consists of highly vesicular rough textured volcanic glass". The word pumice is derived from the Latin pumex, meaning "foam". In fact, pumice is so light, so lacking in density, that pieces of it are found floating in the the waters surrounding active volcanoes.

In the last post, the lamp looked like this prior to polishing (click to embiggen):

After a bit of working, using all the facets of the pumice stones, I was able to get this level of polish (again, click to embiggen for detail).

Note that while some of the deeper tool marks remain, the polish is high enough to allow the natural colour of the soapstone to come through.

And to further underscore the effectiveness of the pumice stones, this is a photo of the lamp wetted on the right side, to show what it would look like with a wax or other polish applied.

This is probably as polished as a medieval stone lamp would have ever gotten, so what we're looking at here is very close to a period piece of work.

(Also, nice piece of stone, huh?)

When carving the dragon on the other side, I will continue my polishing experiment with a piece of bone or antler.

Stay tuned!

Medieval Oil Lamp Part Three: Fixing Mistakes

As promised, this post will examine one of the ways to correct mistakes in soapstone carving. 

When I was cutting away excess stone from this piece, I accidentally went too far with the hacksaw. I could have cut it away and made a smaller lamp, but felt instead this presented me with an opportunity to show students how to deal with these little mishaps.

Below is a photo of the lamp with the mistake in it. You can clearly see a vertical hole in the sculpture, just above the tip of the dragon's wing. (I have already fixed the very top of the hole.)

WTF?

Luckily the materials required to fix this are ready to hand.

Steatite/Soapstone is a metamorphic rock, composed mostly of talc (used in baby powder and cosmetics). The fine white powder you create while carving is talc, and it is this substance that can be used to correct minor repairs.

In a small container, add Elmer's white glue to some of the talc collected from your workspace. I use a painting palette and a toothpick, as below.

You don't need much. Add just enough glue to make a fairly thick paste. Using the toothpick, apply the talc paste to the hole or crack in your sculpt. Wipe away any excess with a paper towel. Keep applying the paste until you are satisfied that the hole is filled. Make it flush with the surrounding stone.

When I was finished, the hole looked like this:

Ta-dah!

Later, we will see how it looks when there is some polish applied to the lamp.

*A word on talc before we proceed.
Talc is a very fine particulate that easily penetrates your sinuses and lungs. When working, always use a mask or respirator in a well-ventilated area. Also, keep your workspace clean. Work on a surface--such a piece of newspaper-so that you can frequently dump the talc into a garbage can or other receptacle nearby. Periodically wipe the workspace down with a damp cloth. DO NOT DUMP TALC DOWN THE SINK! It will turn to concrete in your pipes and create huge issues! Instead, either put it in the garbage, make cosmetics or spread it over the garden to modify the soil.*

Carrying on, I now want to add detail to the dragon. Using an embossing tool and a small chisel, I sharpened the dragon's features, including the face, contours and wings. In a few hours, it went from looking like this:

To this:

There are still lots of ways to add some texture and visual interest to the dragon in terms of working details into the tail and even the jawline. So in terms of finishing this particular dragon (there will be a similar one on the other side of the lamp), I still have some work ahead of me.

Ahead: One period polishing method was to use pumice. I bought a couple of suitable pumice stones at a rock and gem show yesterday, and I am going to experiment with them to see what kind of polish it offers. I will document this process and share it with you in the next post.

Any questions about the process so far? Write to me at talairanperigord at gmail dot com, or look me up on Facebook.

Medieval Oil Lamp Part Two: Bas Relief

With the basic lamp and the reservoir done, the next step is to rough in the embellishment.

I wanted an image of a dragon right out of a medieval manuscript. For this, I cannot recommend Pinterest or Google Images highly enough. I know in the past Pinterest has not been considered a particularly reputable source--one thinks mostly of manic brides and foodies in search of recipes when the name is mentioned.

But I find that this is rapidly changing. More and more historians and medieval artisans are accessing Pinterest, with the result that we find more images that are cited and linked to museums or papers. And if you do encounter an image with no information attached, it's still typically only a matter of time before looking at "Images Similar To This" will take you to the information you're looking for.

The image I settled on was this one. I was especially interested in finding an image that was horizontally oriented and which would be simple to modify.  

Dragon, Guirard des Moulins, Bible historical, Paris, first quarter of the 14th C, BNF Department des Manuscripts Francais, Folio 239

I like this little guy because he has a friendly, cat-like face and is pretty simple in terms of his body shape. Because soapstone is so soft, it is often frustrating to find that crisp detail is difficult to achieve, and this dragon is basic enough that I can add texture and detail to create some visual complexity and contrast.

I scratched out the basic outline using a pencil and an embossing tool. These are easily removed--erased--with a few swipes of a rasp or riffler if you make a mistake or decide you want to make changes. When satisfied with the overall dimensions, I traced the outline with a small chisel. I concentrated on removing the stone around the dragon, so as to cast the design in bas relief. At this stage, I was only interested in the silhouette and none of the interior details. After about three hours, the lamp looked like this.

Rather than letting the tail curl underneath as in the source material, I extended it around the lamp's corner, and gave it a decorative loop (below).

From here, I will remove stone from around the edges of the dragon, sharpening the image by undercutting it slightly. At the same time, I will continue to even out the lamp generally with rifflers. When I feel I have achieved this to my satisfaction, it is time to start on details on the dragon's face, wings and paws.

In the next blog, I will show you my progress and also how to repair a soapstone project when an accident occurs. It doesn't happen often, but it's good to know.

Medieval Oil Lamp Part One: A Brief History of the Oil Lamp

My next project is a medieval oil lamp. 

Oil lamps are an ancient technology reaching back thousands of years across every culture. They consist of three essential parts--a stone or ceramic reservoir (or later, metal or glass), a wick (variously made of cotton, wool, seagrasses, hemp) and fuel (oil or animal fat). We are fortunate in that we have many extant examples of this technology across many cultures throughout the medieval period from which to draw our inspiration.

The image above shows the wide variety of shapes of oil lamps found at an excavation of 10th C. Thetford, UK., and the image below is that of a soapstone lamp found in House Seven at the Norse dig in Jarlshof, Scotland. The lamp dates from the 11th - 14th centuries CE. Holes drilled into the ends of the stone indicate that it was intended to be suspended. (Hey, that rhymes!)


Surprisingly, I have found little in the way of western European lamps once the Norse invaders were assimilated into the local communities. We know there were several methods of lighting available during the Middles Ages--braziers, rushlights, and candles (tallow or beeswax). Oil lamps seem to be missing somewhat from the archaeological record, but enough of them survive to assure us that this technology persisted throughout the medieval period, and indeed, into the present day.

Medieval oil lamp, Museum of London

This image is of a medieval oil lamp (possibly alabaster or limestone) found in the Museum of London. It is different from its Norse predecessors in that it is embellished on the side with heraldry. Possibly, this embellishment is an Islamic influence, sustained through contact made with that culture during the Crusades. Typically we find that Islamic lamps are much more figurative and elaborately decorated than those produced by the northern craftsmen of the same period.

Islamic oil lamp

I have made oil lamps in the past, specifically a Norse longboat and a whimsical (and modern) bear. I am drawn to them as a project because they are at once imminently practical and handsome. I find that there is so much scope for interpretation because they are so simple. 

With this project, I wanted to make a western European lamp of the medieval period that was embellished as above, and still authentic enough to be suitable for reenactment without slavishly reproducing the original. I chose a piece of soapstone in a colour that appealed to me and roughed it out into a rectangular shape. (I regret I did not capture images of the rough stone. Bad artisan! BAD!) The shape is deliberate because while I find the goblet lamps very pleasing aesthetically, I want most of all for the lamp to be safe. There is very little chance of something this broad and low being knocked over.

This is the lamp worked down to its basic shape. It is roughly 3.5 inches long, 2.75 inches wide and 1 1/4 inches tall. The reservoir is approximately 3/4 of an inch deep. The shaping of the rough stone was done the usual way using rasps and rifflers. This process has been chronicled in earlier posts, specifically this one detailing the creation of a soapstone gaming piece.  In the above image, I have included the u-bowl gouge used to make the reservoir.

As always, kids, safety first. Wear protective equipment (respirator/mask), gloves, and always work away from your body. Those gouges are bloody sharp (or should be! Take care of your tools!)

It is my intention to carve a dragon along both of the lamp's long sides and possibly some foliage on the short ends. Our next post will be about the images I am using and how I will render them in bas relief on the lamp.

And for those of you wondering what colour the soapstone is? I'm going to be difficult and not reveal that until the end. So stay tuned!

Soapstone Hound Part Five - Finishing and Polishing

Finally, we have the hound at a stage where it can be prepared for presentation. This part is perhaps the most contentious, because in the Middle Ages, artisans working in soapstone didn't always spend much time on polishing their creations. Extant Norse pots, bowls, and oil lamps clearly show gouge marks left in the stone during the shaping stage. This is hardly surprizing, given the utilitarian nature of the items. 

Soapstone Bowl (9th C?), Denmark, from the National Museum, Copenhagen

We do see evidence of tool score removal in the case of Islamic steatite (soapstone) chess pieces, however. In period, polish was achieved in a variety of ways--pumice stone, garnet "paper" (very similar to modern sandpaper), polishing powder--even seagrasses. In coastal regions, we also see evidence of manta ray skin being used as a polisher.

East Mediterranean chess pieces, (10 - 11 C) (provenance currently unknown) Note the unpolished stone in the crevices.

The modern aesthetic, however, prefers a high polish, especially on artistic or recreational works. A good cleaning and polishing allows the natural beauty of the soapstone to emerge.

Here is where we find ourselves with the Ashmole Hound. We have thus far created the hound using only period techniques and tools, using no rotary tools or electric devices of any kind. Our only concession to modern technology is to use tools made of steel rather than iron (although I do have an iron chisel in my tool kit). We depart now from medieval techniques in order to present a really professional piece that will appeal to both the eye and the touch.

To achieve this, I am using a set of emery boards in various grits from coarse to extra fine. You may, if you choose also use sandpaper. Sandpaper offers a number of advantages, not the least of which is that you can work wet in order to reduce dust and particulates. When using this method, I usually start with a 200 grit paper and work my way gradually up to 800.

Polishing from top to bottom: The raw hound, chisel, and emery boards from coarse to super fine.

I like the emery boards especially on small projects like these. The hound has a number of creases and folds the sandpaper might have trouble getting into. The shape of the emery boards lend themselves to these details more readily.

On my way to hare-hunting glory!

Here is the hound with only his head polished by the coarse board. You can see there is a significant difference between the smoothness between his head and his untouched body. I will now carry on doing the rest of him until I am satisfied with his finish. I will know I am done when there are no more white lines on the surface.

Occasionally, there is a score on the surface that cannot effectively be removed by the emery boards or sandpaper on their own. In this situation, we go back to the chisel. Turn the chisel over so that the bevelled edge is facing away from you. Then gently and carefully shave the area around the tool mark until it is essentially erased. Then carry on polishing with your preferred method.

When the hound has been cleaned up, we come to the stage where we decide on the final finish. In the Middle Ages, if they bothered at all, artisans probably relied on oils or beeswax. Soapstone, being fairly porous, tends to absorb oils quickly and revert to its unprepossessing greyish appearance. Today, artists have a few options. Beeswax gives the highest gloss finish. It is an excellent choice for sculptures that will be displayed and not handled.

I am hopeful that the hound will have a long career chasing that damned rabbit and will pass through the hands of many players. Therefore, I have chosen to coat him in tung oil, which will give him a high gloss finish similar to beeswax, but better protection. In using tung oil, exercise caution. Work in a well-ventilated area and avoid open flame. When wet, tung oil is highly flammable. Allow the tung oil at least 24 hours to dry before handling and applying a second and/or third coat.

Check me out, bitches!

And here is the Hound finally complete. He's a little hard to see because he is SO dark (that is a gorgeous piece of soapstone, I gotta say), but you can see that I have left his collar untreated and added little dots to it, just for shits and giggles. I toyed with the idea of adding beads for eyes, but for now, I have left him relatively unadorned and very handsome (if I say so myself) in his simplicity.

All in all, I am pleased with how this project turned out. It took me about 30 hours all told. I am looking forward to carving his two packmates in order to finish the game entirely.

I hope this blog has been helpful. If you have questions regarding the process on this or other projects you see here, please drop me a line at talairanperigord at gmail dot com, or look me up on Ye Boke of Face.

Cheers!