Sunday, July 15, 2018

Summer Solstice Iron Smelt : RESULTS

As in past years, there was a late spring / early summer iron smelt at Wareham. The date for this June 23 - 'the Saturday closest to Summer Solstice'.
The objective of this experiment was further investigation of the 'Slag Pit' style furnace - tentatively described as 'Celtic Iron Age'.

Refer back to an earlier posting for the build / experiment outline.

Near the end of the main sequence - Neil Peterson probing to determine bloom size.
Hammering on the bloom in place, using the 'Thumper'. (a)
Top Extraction of the hot bloom. (a)
ORE : 28.2 kg
DD 2B = 22.68 kg red iron oxide + 2.5 kg whole wheat flour + 2.75 kg forge scale
  / water to mix, then dried (typically about 10% remains)
CHARCOAL : roughly 62 kg
  Mix of Maple (2/3) and Oak (1/3)
AIR : via electric blower = estimated 900 LpM, increased to 1000 LpM at 4 hours
TIME : about 2 hours from start pre-heat to fill / touching off volitiles
  about 5 1/2 hours for the main sequence (to start burn down)

Initial charges : Iron rich slag (2 @ 1 kg) + Gromp fragments (2 x 1 kg)

Burn Rate : Average of 12 minutes (very consistent)
  First 7 ore additions at 1 kg each
  Next 3 additions at 1.5 kg each
  Last 7 additions at 2 kg each
  Final addition at 2.7 kg (remainder on hand)

Final Bloom, shown upside down, tuyere side to right. (b)

BLOOM : 6.1 kg
YIELD : 22 %
QUALITY : not cut at this point, but hammer feel suggests quite dense.

TEAM : Neil Peterson / Gus Gissing / Margaret Gissing /  Ben Van Eis

Next : Excavation of the slag block...

Image Credits :
a) Kelly Probyn-Smith
b) 'Gus' Gissing

Wednesday, July 11, 2018

Into a new MILENNIUM

This marks the 1000 th posting to this blog. (1)

I started 'Hammered Out Bits' back in March of 2006.

One of the primary reason I started this all was to make use of materials I was generating through answering e-mails. As frequent readers well know, I'm not (ever?) able to make a one word answer - to anything. Even if the actual answer to a question is 'NO', I feel the *reasons* are just as important as the negative response. I also feel that any statement needs some background to be correctly understood. (2) So I end up spending a lot of time on long detailed e-mails, which would end up only having a single reader. You may notice on any number of pieces here, the initial start is a quote from an email. (3)
At the time this blog was started, one of the mechanisms in play was author's intending to collect up all the (often random) segments from their blog into a published volume. Some people early into this method, and those with particularly 'hot' topics, where able to undertake this to financial success. I had some hopes along those lines, especially within the highly specialised topics of 'Viking Age blacksmithing' and 'bloomery iron smelting'. With time however, I can see that at best that volume of raw articles are far too chaotic to form into a concise whole. It would be easier to use the segments as very raw draft - and just write again from scratch.

When I started this blog, I got some very good advice from my old friend Steve Muhlburger :
'Keep to a narrow topic range'
'Try to avoid broadcasting your personal opinions (unless politics is your topic).'
I have mainly attempted to do this here. You will find the primary topic areas given through the 'Lables' list near the bottom of the left side bar (with their numbers) :

Blacksmithing = 328
Viking Age = 278
Iron Smelting = 269
Contemporary Arts = 168
Experimental Archaeology = 141 

Most the other topic labels show less than 50 attributed.
(Yes - those add up to more than 1000. Often an individual post might collect more than one topic label.)
First image published here - June 12, 2006. The 26 posts before this were text only!

Greatest Hits?

This blog, perhaps exactly because of its limited and specialised topic focus, does not have a massive readership:

Regular Reader / 'Followers' = 28
Typical Views on a new posting = 300
Average Views of any posting any day = 150

Total Views Overall = 724,400
USA Viewers (overall) = 340,000 
Russian Viewers (overall) = 71,000
Canadian Viewers (overall) = 62,000

Not overly surprising, given the use of English (although Russian numbers a surprise). Given that Canada is roughly 1/10th the population of the USA, there is a strong showing here. (But again maybe not too surprising, given that I live in Ontario - and do have a 30 + year visibility here!)

Curiously, it has been when I have stepped * outside * the normal topic framework here that I have generated the highest reader numbers.

29 May 2017, 24 comments


31 Oct 2015

 (so combined = 7802 )

1 May 2017, 6 comments

After that, any individual posting averages roughly 3000 views (overall)

You can see that my very, very political entry (on being declared an 'Illegal Immigrant Without Proper Documentation') has received fully * twenty * times more views than any other single posting. Actually almost 10% of the overall total!

The next two high volume postings (over two times the average) are the result of 'hot' popular culture topics. The film 'Avatar' first, the TV 'Forged in Fire' second.
It might be safe to say the fourth high volume entry is also a result of pop culture, in this case various 'documentaries' about what proved to be a totally false Norse 'occupation' site.

So - what is my take away from all this?
I consider publishing on the internet as * real * publishing. For the Independent Researcher (my bloomery iron smelting work for example), access to academic publications is extremely limited, and very difficult. The 'self published' aspect of the internet does provide a clear alternative. (4)
I have information published on the internet in three formats:

the Book = my formal web site (
the Magazine = this blog
Snap Comments (at a cocktail party) = Facebook

As an individual, I consider the sharing of knowledge ethically required.
So expect many more entries here into the Second Millennium...

(1) But well over 1000 blog postings created - all combined.
•  I also contribute to the Dark Ages Re-Creation Company blog
About 50 or so pieces there (roughly half). A number are cross posted back to this blog however.
•  I set up a separate blog to document my 2012 Ontario Arts Council grant funded project Iron Blooms to Bars.
There are over 40 pieces there, again a number are cross posted back to this blog.

(2) Hence my increasing aggravation over the development of 'personalities' / 'sound bites' / 'Fake News' over the last decade particularly. Most events and issues can not possibly be understood in 140 characters.

(3) Warning there:
If you send me an email, there is chance my own reply may be converted / expanded into a blog posting.
My standard practise is to remove identifiers, reducing the initial email to a shorter quote, usually only attributed to a first name (for sender's security)

(4) I have had many conversations with academics about the value (or lack thereof) of the internet. 
The easy access to virtually anyone who can find a computer and has even basic computer skills is clear.
With at least simple writing skills, anyone can self publish.
There are two commonly pointed out flaws to information on the internet :
1) Self published means absolutely no editing or checks for accuracy. In this the internet requires the * reader * to provide the required critical evaluation of materials found.
2) The medium is very ethereal. Often web sites disappear without a trace - that content lost forever. 
(Consider here the length of duration of this blog (2006). The main Wareham Forge web site has been stable since the late 1990's.)

Tuesday, July 10, 2018

Summer Solstice IRON SMELT

As in past years, there was a late spring / early summer iron smelt at Wareham. The date for this has been pegged to 'the Saturday closest to Summer Solstice', this year June 23. (1)

The objective of this experiment was further investigation of the 'Slag Pit' style furnace - tentatively described as 'Celtic Iron Age'.
To date I have attempted variations on this basic process three times :
October 2011 - Branton's Run limonite (?) - no iron produced
November 2011 - industrial taconite - 6.4 kg / 33 % yield
August 2017 - DD1 analog - 2.9 kg fragments / 15% estimated yield

Theoretical layout - August 2017
In this series, the body of the furnace is our standard 'short shaft' design, built again of clay cobb (clay / sand / horse manure).
The primary difference is in the slag management method. Here a pit is dug below ground level, before the furnace is constructed above it.
1) The pit is filled with vegetation.
2) There is a clay cap placed above the pit, sealing this off from the working furnace above.
What is supposed to happen is that the vegetation below supports the clay cap during the drying fire and early cycle of the working furnace - until the slag bowl forms. As excess slag is generated, it is allowed to drain through the clay cap, down into the pit below. So a kind of 'internal slag tapping' (2).

Early Iron Age slag block, Denmark
For attempt # 1 and #3, the primary failure was with the clay cap itself.
The first experiment used sturdy sticks of willow as the vegetation, but the clay cracked and broke too early in the main smelting cycle, before the slag bowl had really formed. (This compounded by use of a questionable ore - which might not proved iron rich enough for effective iron production to begin with.)
Test two used a virtually identical design, but with a proven (effective!) ore. The results here were excellent, both in terms of bloom production and the slag block remaining.
Test three was certainly a disappointment, given it took place as a public demonstration at the Scottish Crannog Centre. The first clay plate actually cracked and failed during the drying fire. (This may have been partially the result of using dried grass and not packing tight enough?) The pit was re-filled with vegetation, and a second plate installed. It too broke too early in the smelting cycle. (Not unexpectedly, with wet clay exposed to high furnace temperatures!)

Proposed Furnace Layout = 6/18
It had been hoped that one of two on hand furnace bodies from previous smelts could be re-used. What happened is that the first (from November 2016 course) proved not built sturdy enough, and it broke apart when I attempted to shift it.

The first step then was to dig a pit in the centre of our normal smelting work area.
Always a challenge at Wareham!

'Completed' Pit
As usual, the ground here is far more stones and rocks than actual dirt. The hole was intended to be a clear rough cylinder, 20 cm in diameter and 30 - 35 cm deep. What you see above is the space created is about half full of head sized rocks. My hope was that there would still be enough empty volume for the slag to accumulate. (And I did take one that size * out * of the hole!)

One of the first questions from earlier attempts was how to best select the vegetation, then how to best pack the pit with this material.

Kelly picking some of the chosen plants
Packing the Pit
Over a good chunk of the yard, there is a 'weed' plant that grows up. It has a woody stem, with closely attached long, narrow leaves along the stem. The height is roughly 60 cm, and it pulls out of the ground reasonably easy (roots are a shallow ball). It proved easy to pull up a good quantity of these, and when folded into rough thirds it was simple to pack the entire pit tight with the plants. I suspected * fresh * plant matter would better resist the temperatures of the lower surface. I had hopes the high water content of the green plants would also help the organic packing survive long enough for the slag bowl to form and support the upper weight of charcoal inside the furnace.

Forming the clay 'cap' over the pit.
The second of indicated past failures (especially at SCC in 2017) had been caused by breaking of the clay cap which formed both a lid to the pit, and a floor to the furnace itself. Earlier experiments had used a clay disk in the 1 - 2 cm thick range. This time I decided to use a more robust construction, closer to 5 cm in thickness. This was made up from straight clay, in this case a high temperature material called EPK (rated not to melt to 1750 C).

Furnace Build - tuyere in place.
The second furnace body on hand was originally built in 2012, and used at least three times already. It proved to have basically survived previous uses and the freeze and thaw over the winters. It was built of a clay / sand (50/50) mix (which is the version used by friend Lee Sauder to his good result). To improve durablity, my furnace had been built inside a steel garbage can, base cut out and turned upside down.
Originally this furnace had been mounted on a concrete block plinth. (Filled with charcoal fines, that construction allows for easy dropping of the slag bowl to produce larger blooms, and simplifies bottom extraction method.) To ensure the correct space below the tuyere, here the furnace was set on top of a number of half bricks, sealed with straight clay. The proper depth of the base was set by adding a layer of sand / wood ash mix on top of the clay cap.

Setting Tuyere Angle
You can also see the copper tuyere set in place in the images above.
I have written many times (both here, on the main Iron Smelting documentation, and in published articles) about the importance of setting the correct tuyere angle for a well functioning furnace. You can see the method I use to establish this correctly in the image above. I have simply made up a small sheet metal triangle with the 'ideal' 22.5 degrees to one corner. With a small pocket level, it is easy then to find tune the tuyere angle, which is only rough set when the hole is cut into the furnace body.

Other work on this first 'build and prep' day included hauling out all the smelting tools and equipment, setting up both a charcoal prep and the visitor's area.

Enough for one day! (And one blog post...)

(1) This event, along with the 'Thanksgiving Weekend' and 'Samhain' ones, continue to be part of ongoing experimental investigations into early bloomery iron smelting methods.
All are considered 'Open Invitational' events = meaning that interested observers are welcome to come. I do ask that you contact me before coming up however. This primarily to calculate septic loading and parking spaces.
There is usually some possibility of becoming directly involved (there is always 'dirty work' to be undertaken!). Those hoping to participate are warned to dress in suitable work clothes.
These are not intended as teaching events however (see the 'Introduction to Iron Smelting' course)
(2) The slag pit arrangement was common throughout Europe, roughly up to the end of the Roman period. The upper furnace structure itself varies, ranging from earlier smaller bellows blown to huge (Roman) natural draw types. The slag blocks created are almost indistructable, and thousands remain. In Denmark alone, over 2000 have been found. Typically these are roughly the size of a bushel basket. (Image above is from the lower Jutland area, seen on my 2008 trip.)

Thursday, June 28, 2018

Owen Sound Artist's Tool Sale

A Special Note to Fellow Artists
Owen Sound Artist's Co-op is renting the building directly beside the Co-op gallery, to establish The Workshop, permanent studios for classes in clay, jewelry and printmaking.
The fundraising is underway.
On July 7 during the Hottest Street Sale the Co-op is hosting a Tool Drive.
If you're downsizing, if you've got too many tools, if there's anything you can donate please let me know! Some donations will be reserved for The Workshop.
Surplus tools and equipment will be sold on July 7 at the Workshop space.
You can bring your contributions to the Artists Co-op during the week before July 7. (You might get a sneak peek at the new space!) We can arrange pick-up of larger items (wheels, kilns, presses, etc.) on June 28 and 29.

Acquire some affordable tools for yourself or for an aspiring artist. Come and see our new Workshop space during the Hottest Street Sale.
If you want to contribute financially, please get in touch so we can arrange for you to get a Charitable Tax Receipt.
Maybe you're interested in taking classes? Maybe you're a professional artist who wants to teach classes? Please let us know!

519 371 0479
Owen Sound Artist's Co-op
942 2nd Ave East
This came in earlier this week. 

May be of special interest to those in the Grey - Bruce / Owen Sound region.

Sorry for the quality of the logo - image poached and altered from their web site.

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

COPYRIGHT NOTICE - All posted text and images @ Darrell Markewitz.
No duplication, in whole or in part, is permitted without the author's expressed written permission.
For a detailed copyright statement : go HERE