Practical Bloomery Smelting

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Practical Bloomery Smelting W. H. Lee Sauder and Henry G. Williams III Woods Creek Forge, 229B McLaughlin Street, Lexington, VA 24450 Washington & Lee University, Lexington, VA 24450

ABSTRACT The art and technique of bloomery smelting, man’s original method for winning metallic iron from its ore, has been largely lost in recent centuries. Many reconstructions of this technique have been attempted by archaeologists in the last 30 years. These experimental smelts have tended to be rather disappointing in terms of the production of usable iron; nonetheless, many conclusions have been drawn from this work. The main goal of our work with bloomery smelting is the production of iron for the creation of forged sculpture. Our focus on producing a usable product has led us to a somewhat different view of the technology from what has been published in the archaeological literature. In this paper, we will briefly summarize our work through the spring of 2000, which has been published elsewhere. We’ll then report our recent findings from the 2000-2001 smelting season, describing a typical smelt of the most efficient smelting regimen we have yet discovered. We will pay particular attention to methods that differ from those of other experimenters, especially in regards to blowing rate, slag management, and the recycling of furnace products. Finally, we’ll point toward areas of upcoming research. INTRODUCTION Summary of early work We have been experimenting with the bloomery process since January of 1998. From the beginning, our primary goal has been to smelt iron of sufficient quantity and quality for the creation of hand-forged artworks, and to explore the process for a deeper understanding of iron as an artistic medium. We have strived to remain open to what the iron itself has to teach us, and to keep scientific knowledge in the background. Our interest and expertise is in iron and ironworking, not in archaeology or metallurgy. We feel that this devotion to the process and its product, rather than to furnace morphology or slag residue, has led us to uncover an approach to bloomery smelting that has the potential to provide more accurate data for historical and archaeological research than the current predominant models. Our first 11 trials provided us with valuable experience but produced only the most pitiable examples of blooms. These early blooms, besides being fist-sized at best, all had elevated carbon contents that made most of them unforgeable. We attempted to deal with these problems by reducing both the fuel:ore ratio, and lowering the airflow and temperature, with disappointing results. Our first truly satisfactory bloom resulted from an attempt to make cast iron by increasing shaft height, fuel:ore ratio, and, perhaps most significantly, air flow. From this serendipitous beginning, we have evolved a very efficient smelting regimen based on minimal preheating, air II10.9.1

flows from 1200-1600 l/min, the recharging of tapped slag, and the recycling of residue from the previous smelt. With experiments #21-27 , condu