Note : This commentary was written in 2016, intended to be my contribution to the then planned booklet describing the Turf to Tools project, which would have included a number of other authors. Readers will find much of this material incorporated into the finished paper from 2023.

Turf to Tools
A View from an Artisan Maker

Darrell Markewitz

Turf to Tools was initially conceived as "... an ongoing investigation in to landscape, material and craft, inspired by local archeological investigations in Rhynie, Aberdeenshire."

I come from a camp that lays between the pure conceptual Artist and the Technician. As I understand these terms at SSW, the Artist being defined as one most concerned with developing ideas. The Technician being more concentrated on physical methods. As an Artisan Maker, my own work is often bounded by functional considerations, but I strive to design an object still pleasing to look at. There may be an element of the thought provoking as well, but most commonly this remains secondary to the demands of function and the desires of form.
As an individual, I find myself a bridge between a number of quite different fields. I have a long working experience in the very technical realm of the blacksmith / metalworker. Along with having come from an formal education in art school. Being known as knowledgeable in early North European, especially Viking Age, material culture - and the public presentation of the same. In recent years becoming more and more involved in experimental archaeology (itself a span between the academic researcher and the practical field worker).
Each 'camp' has its own method of both approaching subjects, and often distinctive (even conflicting!) descriptive language. Added to this ball of string is the fact that there are international differences, including (certainly at the Scottish Sculpture Workshop) multiple language users.

Given I'm from Canada, with a large body of work ranging over many types, and with 'many irons in the fire', what can I say about the Turf to Tools project?

My involvement with Turf to Tools came in through the side door. Eden Jolly had initiated what I would call a 'proof of concept' for the over reaching frame of the project : utilizing local raw materials, through regional historic based methods, to create functional objects. His background research into this all lead him to my own internet available documentation. A personal conversation started via e-mail, helping him with his first attempt at a bloomery iron smelt. Someplace along this line, Nuno Sacramento had contacted me to see if I would be interested in coming to SSW and directly participating in the project. In this case, those 'many irons' appeared to provide an ideal mix of historical knowledge, technical skill, practical experience, and (perhaps) artistic vision needed.

The first phase in 2014 most certainly was shaped by the archaeology of nearby Rhynie, for which the inclusion of Dr. Gordon Noble on the project would prove of importance. So to start, T2T was framed to a 'Pictish' cultural set : North Eastern Scotland, post Roman to pre - Viking (so 400 - 800 AD). It is a period where the minor chiefdoms are expanding to small kingdoms, and Rhynie appears to be the site of one of those political centres. Historically this period presents some major problems, as this is a material culture not well represented by artifact in archaeology. Importantly at that point Christianity is becoming the major religion. (This significant because one change with Christian conversion is the end of a more ancient practice of burial with a person's life goods, thus now limiting objects into the artifact record, especially those of daily life.)

Evidence of ancient iron smelting technology is almost always fractured, and honestly not well understood. Looking for specifically first Scottish, then narrowed to Pictish period samples at first seemed unlikely. Fortunately, it proved possible to find some descriptions of an excavation of a small scale historic iron production site at Culduthel, just outside Inverness. Both the close location, and the rough dating from 200 to 400 AD, is almost good as it could be within the random nature of archaeological discoveries. Past work in the realm of experimental archaeology would prove critical here, allowing for a fuller understanding of exactly how available iron ore was transformed into workable iron bars.

The enigmatic figure found in 1978 carved in a large stone slab, the Rhynie Man, would channel the 'object' part of the undertaking. The cartoon like figure, likely created some time about 400 - 600 AD, holds over his shoulder an axe. Who is depicted? What is and Why is that axe shown? What is the original reason for the exaggerated details : pointed teeth, big hooked nose, hair or head-dress? To make this all more difficult, no artifact axes have been found in Scotland for the period of reference. Within all of Great Britain, only a mere handful have been found. Searching for a possible artifact prototype would prove not only difficult, but interpretations of that sample became a point of discussion within the project.


Checking the air system, T2T smelt 1.2, 2014 (image by Kelly Probyn-Smith)

The basic equipment design employed is what I call a 'short shaft' type of direct reduction iron smelting furnace. This consists of a cylindrical or slightly tapered clay cobb body, about 60 to 70 cm tall and roughly 25 cm interior diameter. The walls are hand built up from a mix of 1/3 course sand, 1/3 clay and 1/3 shredded dry horse manure. The manure addition reinforces, gives steam on drying some place to expand and burns away on the interior to create a primitive refractory material. A tuyere pipe is inserted about 15 - 20 cm above the base level, standing 5 cm or so proud of the interior wall. The ideal angle for this is about 20 degrees downwards, and this serves to deliver the air blast into the interior.
Hardwood charcoal is the normal fuel (almost universally), and needs to be of a certain size. Ore as well needs to crushed to an ideal size, which varies depending on type of ore. There is a dance between ore type, charcoal, clay used and the final ideal size and layout of the furnace, and the amount of air, both volume and pressure. Change too much of one, and all the other elements need to be modified. (This is primarily why historic furnaces vary so much for different physical locations.) Past experience has shown for this type of furnace, the ideal rate of burning is 2 kg of charcoal (about 8 litres) every 8 - 10 minutes, a process that continues for many hours.
Ore is mixed evenly through the charcoal as it is added to the top of the furnace. Iron oxide ore meets hot carbon monoxide gas from the burning charcoal. This wants to be carbon dioxide, so the oxygen is reduced from the ore, leaving fine metallic iron particles behind. With an interior at about their welding temperature, the particles stick together (sinter) like dark brown sugar does. This material falls to the bottom of the furnace. Also falling to the bottom is a rough glass formed from sand (silica) in the ore, melted clay walls and ash from the charcoal. This also falls, hits the cold bottom of the furnace and freezes, but remains liquid on the top, nearest the air blast of the tuyere. Iron falls into this slag bowl, sinking through the hot liquid glass and stopping on the more solid bottom. (Think of a chocolate covered cherry, the chocolate the slag bowl, the cherry the iron bloom, the liquid slag the sugar syrup.) At the end of the smelt, the base of the furnace is opened to expose and crack apart the slag bowl, then grab the metallic bloom that (hopefully) has been produced.
And yes - an amazing number of things can go wrong in all this!

As with any complex project, mere mechanical problems often interrupted the chain of exploration.
Building the initial iron smelting furnace was fairly straight forward, overall based on Culduthel, but including those elements found through experience most likely to ensure effective results. What I call a 'short shaft', in this case mounted on a plinth made of stones and This base design was pre-tested at my home workshop in Canada months in advance. Application of a construction suggestion by George Beasley, based on his (extensive) experience with cast iron furnace operations was quite helpful.
The first test included use of a unique local iron ore called Macaulayite, which proved not to be an effective raw resource. (Note that the better part of two days effort and the expenditure of some 60 plus kg of prepared charcoal were expended!) The end result here was a small iron bloom at 2.3 kg, an ore to metal yield of only 7.5 %.
This second firing using primarily industrial taconite ore should have produced significantly better results, but in the end the bloom was only 2.9 kg, a 11.5 % yield. Although jokes were made about Scottish weather, the more likely reason was the air supply system, via a small electric leaf blower.
The third test required the building of a second furnace. This because the first furnace had been constructed on a wooden pallet (topped with concrete paving slabs) to allow it to be shifted around the work area. As it happened, moving a clay smelting furnace proved not such a great idea, and resulted in extensively damaging the structure. Input from artist Deirdre O'Mahony lead to a question about utilizing peat as a fuel source. As the new furnace needed to be baked dry, a test using suitably broken up modern commercial peat pellets as fuel was undertaken. Although only a short burn, thermocouple readings made suggested temperatures into the correct operating range might prove possible (1140 - 1250 C recorded).
The third test would utilize a proven ore type, an analog developed specifically to mimic naturally found primary bog iron ore. The furnace design was essentially the same as before. The most major change was the use of a stronger blower, ensuring better delivered pressure to better force air into the furnace. In addition to the primary iron making activity, Emma Harrison would contribute both her effort but an additional experimental process at the close of the smelt. For her own research project, a total of 4 kg of raw bone was added in an attempt to create a high calcium layer to the top of the bloom mass. Taken together, the skill of the team and the use of proven elements showed in the excellent results. This time an extremely dense 11.6 kg bloom was produced, a yield of 29%. This bloom later proved so massive that staff at the University of Aberdeen were unable (with modern tools!) to effectively section it.

Along side all this effort was the 'bloom to object' part of the project. This was directly related to Rhynie Man, specifically that axe. I had made a prototype back in my Ontario workshop, conforming to earlier research I had undertaken to Viking Age tool axes. To my eye, the Rhynie Man's axe was a well known early 800's fine tool axe type, quite common in Norway. These slender blades, mounted to a 60 cm or so handle (as seen with Rhynie Man's) are designed to take a fine sliced shaving off a wooden beam, for either house or ship construction. Of course, any tool balanced for fine cuts to wood will also make a deadly weapon. In my opinion, the Rhynie Man Axe was an accurate depiction of a somewhat expensive, but purely functional, tool / weapon.


Axe Prototypes made in T2T, Rhynie on left, Sutton Hoo on right

As mentioned, there are no artifact axes that have been found in Scotland from the Pictish period, and very few found in England either. One of the few well known is the 'axe hammer' from the Sutton Hoo ship burial in East Anglia. This is clearly a Saxon culture, has many pagan elements, but is roughly contemporary at 624 AD.
As part of T2T, I hand forged a rough replica of that object for direct comparison with the Rhynie axe. With the Sutton Hoo axe in hand, again a likely use suggests itself. Even with the lighter axe head and the heavier shaped iron handle, Sutton Hoo certainly feels like a weapon intended for use on horse back. All though it is most likely we can never know for sure, but the creation of accurate replicas brings ancient objects to life.

As a further extension into exploring the world of Rhynie Man, Kelly Probyn-Smith undertook working towards making a replica of the axe headed pin that had just been uncovered at the excavations. This small straight pin was a type most commonly used to secure a cloak at neck or shoulder (depending on the sex of the user). The upper terminal flared to an axe shape on one side, the other side being drawn out then formed to a spiral coil. This appeared on the radiograph reference images to end in serpent's head. Forging such a small object presents its own set of difficulties. Curiously the small set of 'jeweller's' sized tongs also recovered in the 2014 excavations at Rhynie would be the perfect tool for such delicate work.

After all this historic and technically focused exploration, I was certainly very keen to also create a physical object with a more modern context. I selected half of the first bloom created, and forged out a small bowl. Bloom iron is different than modern metals, in terms of alloy content, physical structure and importantly, working character under the blacksmith's hammer. As an artist, I continue to be very interested in working with these differences, and how in these in combination mark a finished object.

The second phase in September of 2016, would continue exploring both the initial concepts, and new aspects based on the discoveries from phase one. Three more iron smelts would be undertaken again using the same basic furnace design.
A field trip in 2014 was to the nearby Lecht Mine, part of investigating the land and local resources. This open cutting along the edge of a small rift in the hills was operated in two phases historically. In the early 1800's, manganese ore was extracted there, causing the building of a stone structure with a small water powered crushing mill (the shell of which still remains). Earlier in the mid 1700's, iron ore was extracted. I had stumbled over (literally!) a thin vertical vein of what looked like it might be usable geothite ore. At the start of the 2016 phase, we returned and gathered four pails of this ore, quality varying by the individuals gathering. The ore gathered at Lecht was roasted, sorted and crushed.
A new furnace was constructed, very similar in size and layout to the ones used in Phase 1. One difference for the first smelt was the use of a copper tube as the tuyere. This was forged into a thick walled taper, about 1.5 cm interior diameter on the insert end, and 40 cm long.The operation of the smelter was fairly standard, save that considerably more iron rich slag was created than normally seen. This required four major slag taping interventions to drain the excess lest it 'drown' the air flow at the tuyere. In the end a large block of yellow hot slag bowl was extracted, but with hammering only a small amount of iron was found. Total production 3.5 kg, yield at 8%. This indicates the ore gathered (remaining?) at Lecht, although able to create iron, is too low in usable iron content to balance the considerable effort and expenditure of other resources to effectively extract it.
Smelt two was a full scale test of peat as a potential fuel. Commercially harvested and compressed pellet peat, sold as home heat fuel, was purchased. Without specific experience, the peat was broken to pieces similar to those proven effective with hardwood charcoal. Again the addition and measured consumption was against pails of 2 kg. The ore used was a red iron oxide analog mix. One other modification was the addition of 3 kg of crushed high iron content slag for the initial charges. Although the peat fuel certainly appeared to be consumed faster than with charcoal, temperatures measured by thermocouple indicated lower than normal internal temperatures. At the end of the smelt, this was born out by the results, with only 1.5 kg of fragmented iron being recovered, yield at just over 4 %. A large quantity of foil like metallic gromps were also collected. Both suggest iron was being reduced, but temperatures were not quite hot enough to effectively sinter this together into a solid bloom mass.
Although this was intended to be the end of the smelting events at T2T2, Eden and Uist Corrigan decided to undertake an additional test (while they had me around to observe and assist as needed). Enough charcoal and taconite, both proven components, remained on hand. The furnace that was initially constructed proved extremely durable, needing only minor repairs around the extraction arch each time. For this last smelt, a short piece of high temperature ceramic kiln support tube replaced the copper for tuyere, into the same position. Once again 3 kg of iron slag was added as the first charges. (The logic here is to more quickly form the required bottom slag bowl.) After all the available taconite ore was added, a further amount of mixed Lecht ore and metallic gromps from smelt 2B were also included. Another change was the addition of a small slag port to the bottom of the furnace, making possible a continuous tapping process. The end result was excellent, with an extremely large and compact bloom at 9 kg, yield at 26 %. This certainly proved the effectiveness of the furnace operation - and the skill of the working team.

Although the intent of phase two was to devote several working days to the second stage process, bloom to bar, followed by the third stage, bar to object, this in the end did not prove possible. Although work had begun earlier on a new 'professional' level blacksmith forge for SSW, this equipment suffered some teething problems in getting it working correctly. Work was also massively impacted by what proved a serious problem in securing effective coal fuel. After several quite unsatisfactory tests, and considerable outside consultation, it was found that the 'best' (if not only) available coal was in fact imported from Poland. This itself was a major surprise, and certainly reflects directly back the the framing concept of human impact on natural resources.

One conceptual project that arose during the 2016 session was one suggested by an even older cultural practice relating to iron objects and landscape. In the more distant Celtic Iron Age, ornate and expensive objects (particularly jewellery and weapons), where often returned to the bog as sacrifices. Weapons used were often bent beyond use - symbolically 'killed' - before being deposited. Everyone on the Turf to Tools team thought the ideal of making a finished object from our precious bloom iron, then returning it to the bog from which the starting ore sprang, would make a powerful last stage to the overall project.

as Rhynie

Posing as Rhynie Man at SSW, 2014 (image by David Porter)

All these technical descriptions aside, Turf to Tools was (and remains) a project examining a complex progression : from resources out of the natural landscape, processing these into basic raw materials, then converting those materials into finished objects. At every step, limits may be imposed and choices are made concerning availability, knowledge, skill, and design. All of these may then channel back into each other. The influence of ancient, traditional, modern, (even conceptual) realities also shape the possibilities. Overall lays the understanding that man has, and continues to, modify the physical world around him. Even in ancient times, it is clear that any modification towards one desired goal may have massive impacts on others, known or unknown.

© Darrell Markewitz, 2016 / 2023