Tuesday, August 12, 2014

First Iron Smelt for 'Turf to Tools'

This is a fast overview of the progress so far at the "Turf to Tools' project at the Scottish Sculpture Workshop:

Team : (L-R) Thomas, James, Eden, Darrell

Air System, just as first graded charcoal is being added.

Initial Compaction - slag mass has been struck off at this point.

Forging the edges of the bloom.
I arrived at SSW later on Friday.
Saturday was filled with general preparations, and forging up some of the specialized tools expected to be needed for the smelting processes.
Sunday was preparing the ore and charcoal, then mixing the materials for the furnace and building it. (For a general description, see the earlier blog posts.)
Monday was smelt day - expected to be the first of three over the project.

31 kg of mixed ores were prepared. Primarily this was a mix of the local (unusual!) Macaulayite ore, with added industrial taconite. There was a small amount of red iron oxide analog used as well.

The furnace ran extremely well, consuming 2 kg of graded charcoal an average of every 11 minutes. This rate was much more consistent than normal in fact. Charges started with 1 kg, and mounted up to 2 kg per charcoal measure.

There was in fact more slag produced than normally seen.
The slag bowl formed higher than usual, and had a sharp edge turned up only about half way across the furnace. This was thought to be because of the blower used, which likely was not producing as much delivery pressure as the standard unit employed back in Wareham.

The finished bloom weight was just over 2 kg, not the best yield. This is considered to be an effect of the Macaulayite ore, which in fact may be a bit low in iron content. (Visually, this material looked quite 'sandy'.)
The extracted bloom, cleaned of slag, was a saucer shape, about 5 cm thick at the edges and roughly 20 cm in diameter.
Several compression steps were taken  on a large block using two strikers. At this point the 'plate' was transferred to a coal forge, where the edges were worked in and the entire mass was further compressed.
Work for this day (!!)  finished up by cutting the bloom into two rough half pieces, ready for further compacting and welding to consoldate the iron to a working bar - the work planned for Wednesday.
The initial furnace build was done

Monday, July 28, 2014


Copied directly from the SSW web site:

NEW Course!

Tuesday, 8th 2014f July, 2014

From Turf to Tools - The Aristotle Furnace
Artisan Blacksmith Darrell Markewitz will be leading a weekend course in bloomery iron production. Darrell, joining us from Canada for the Turf to Tools project, has over 35 years experience as an artisan blacksmith, with particular experience in ancient bloomery and forge processes.
This course is for anyone interested in metal as material, as well as those studying historic ironworking processes – in production or research. All participants will find the Aristotle a quick 'table top' method for producing small amounts of useful metal. The 'Aristotle Furnace' is a small charcoal furnace that will convert any kind of iron into a cake of metal with a set carbon content. In effect it allows conversion of scrap into a tool making material. The resulting 'puck' has the physical texture of a bloomery iron, but at a carbon level suitable for cutting blades.

In this two day / 16 hour-long hands on workshop, participants will first build, then operate their own furnace. A number of roughly 500 gm 'pucks' of metal will be made, experimenting with different starting materials. Finally, using a coal forge, individual pucks can be consolidated into working bars. If time permits, a small Iron Age style chisel or blade can be rough forged.

The course is open to all regardless of previous experience or ability, although those with background or knowledge in metal processes will definitely gain an invaluable experience – not to mention a new table top furnace that you can take away with you. All materials are included in the course fee, and participants will be provided with all the tools and safety equipment needed. Students must come dressed in long pants, all clothing of natural fibres (cotton, wool) only. Boots of some sort are required, ideally above ankle height.
Your instructor is Darrell Markewitz. He is a professional artisan blacksmith from Ontario, Canada, with over 35 years experience at the forge. A major area of his work has been with objects and processes from the Viking Age. He designed, created and implemented the living history program at L'Anse aux Meadows NHSC for Parks Canada, ongoing since 1996. His involvement with Ancient and Early Medieval bloomery iron smelting started in 2001, and he has undertaken over 55 experimental smelts since then. He is one of the founding members (and instigators) of the Early Iron movement in North America. Find out more via his web site www.warehamforge.ca
Title:   Aristotle Furnance
Date:  10am - 6pm Saturday 30 August to Sunday 31 August
Venue: Scottish Sculpture Workshop
Price: £180
To Book: please emaily Emily@ssw.org.uk or call 01464 861372

Sunday, July 27, 2014

Turf to Tools - Official Release!

From Turf to Tools – Rhynie Man Axe

Saturday, July 19, 2014

a bit about HAMMERS

(edited from an e-mail)

Although you can make due with almost anything, precision requires control, and hammers are pretty individual. This is primarily due to the dynamics of the human body. Those who have seen me know I am tall, thin and relatively light framed (5 ft 11 / 155 lbs). This usually means a more balanced head shape, and a longer, typically thinner handle.

The weights are also important. For most lighter weight forging, a 800 gm (1 1/2 lb) is going to be most useful (and desirable). For the heavier work (really much over 1/2 square bar) a 1000 gm (2  lb) is going be required.
I personally find a 1.5 kg (2 lb) a bit heavy, although if the design is good, can manage it with care.
' Impact energy of a stroke is mass times velocity '. Leaving mass penetration aside, with my lighter frame, I tend to use a lighter hammer moving faster, with more stokes and the ability for better control. (I have seen over the years, too many people, especially the hobby smith, will use much too heavy a hammer. Then complain that their elbow hurts! ' It don't matter how hard you can hit - if you miss! ' )

Typically, any smith will have one hammer which is their primary. Then a couple more they use for more specialized forming. And then a pile of hammers they virtually NEVER use. 
A useful piece of advise : Don't rush out and buy an expensive hammer just as you start. Best is to try a number of different profiles, to find one that best suits you personally., * Then * spend the money for what will likely become your primary forging hammer. (A good quality hammer can easily run $75 +) There is no significant reason not to just purchase 'cheaper' hammers - for those you only rarely use anyway.

Check and see if you have any local sources for 'cheap' hammers. Surplus stores and 'low end tool' places can often be a good source.  We can get some square faced cross peens in Ontario that come in from China. While I am * not * in favour of Chinese tools in general, these run less than $10 around here and are acceptable quality, especially as 'seldom used' hammers. 'Twin Swallows' is one brand name.

'Historic - Square'
These are both Chinese square faces, in the classic cross peen shape
These used to come with very poor quality wooden handles (which you basically want to replace with proper ash handles). Then for a while they came with fibreglass as seen. The fibreglass is not ideal, but actually better than what ever crap wood they once used. Lately, these come with * plastic * handles, which is virtually impossible to use. (Every stroke seems to bounce the return into a different direction - very difficult to control!) Balance that against the cost, $8 here last I bought one.
The heads are made of a basic quality mid carbon steel.
I will buy these, take off the handles *, and re-forge the heads to make other shapes. The second hammer is one such, re-shaped to replicate the shape of hammer found in the Mastermyr tool find (Gotland, Norse, c 1150)

'Round Face'
Here are two 'antique' hammers, one at 1 1/2, the other at 2 lbs. This style was common here for farriers in the early 20th. The weight is fairly central to the handle, and they are reasonably evenly balanced, front to rear. The faces are fairly wide, and typically the peen is quite broad. You do have to keep your eyes open, but around here at least there is a fairly good supply of these. Typical prices are about $20 - $25 each.

This is a 1000 gm size (for comparison), with a kind of 'semi octagonal' head shape. The peen is medium to sharp. I find this specific hammer quite balanced and easy to control. I got a number of these, an end of lot from a closing factory here in Eastern Ontario. 

This is  * my * hammer. I've been told it is a German Engineer's Hammer, produced in the inter war period. I have only ever seen one other one in all my years smithing and travelling. This is an 800 gm, I must do at least 80 % of my forge work with this hammer - and have been using it some 30 plus years at this point. (Surprise is that I got this at a yard sale for all of $8, completely at random - just as I was starting to get serious about blacksmithing.)

* Home Hardware (here in Canada) sells a " 16" Blacksmith's Hammer " handle. Get your local to check their inventory, they likely will have to order them in for you. (And keep a spare in the shop!) Cost is about $7. These are an excellent straight grained ash or hicory. They have the required oval eye (not square like a carpenter's hammer). Do remove the varnish (prevents blisters) and re- shape the handle to thin it out below the head. (Better to break a handle than put extra shock into your elbow!) You can see I wrap some hockey tape around the shaft below the eye - this is to protect the wood if I miss when forging elaborate curves around the far side of the horn. (We all miss * sometimes * !)


February 15 - May 15, 2012 : Supported by a Crafts Projects - Creation and Development Grant

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