Experimental Iron Smelt
the Wareham Forge
Sunday Oct 13, 2109

‘Icelandic’ Stone Block - Re-used Slag Bowl

The furnace construction is one variation suggested by the excavations at Skogar, Iceland, in combination with the very real problem of available materials in Iceland. (1)
The on hand stone block furnace was constructed and test fired in June 2019. (2)

Excavations at Hals show clear C shaped remnants of the slag bowls created during an iron making sequence. (3)

Most of the experimental tests undertaken at Wareham involve attempting to explore limited variables, focused to understanding historic process. To that end, it is common to only use any single furnace build at most only 2 or 3 times - often only a single use. The standard has been to completely clear away any remaining interior debris of slag before a second experiment.
It was noticed that the fragmented slag bowl from the June smelt closely resembled what was seen on the excavation drawings from Hals (and other sites).

The set up for the upcoming experiment will be to use the existing stone block furnace, retaining the slag bowl still in place (about 2/3 of the initial).
• ‘standard’ furnace layout (4)
• copper tuyere
• electric blower (high volume air)
• ‘DD2’ ore analog / 30 kg (5)

The specific question?
How will the retention of an earlier created slag bowl effect a second firing in the same furnace?

Interested in Attending ?

Day start : 9 AM
Main Sequence start (typically) : about 10:30 AM
Extraction (estimated) : 5 PM

This event is considered ‘Open Invitational’
Those wishing to attend are welcome, but I ask you e-mail me (info@warehamforge.ca) so I can manage things like parking and support equipments.
This is not specifically a teaching situation. There will be plenty of chances for those keen to both learn and especially participate. (Dirty jobs to be done!)
Those hoping to directly participate should wear work clothes of all natural fibre, and ideally wear boots that fit up over the ankle. Safety eyewear and gloves will be provided.
People are advised to bring lunches with them, the working team can expect to grab while they work.

Directions :

The Wareham Forge is ‘pinned’ on Google Maps
The location is roughly 1 1/2 hours north of Brampton, just off highway 10, beyond Dundalk.
(About 2 hours NE of Waterloo for any ML302 students)
http://www.warehamforge.ca/directions/index.html

Darrell Markewitz

(also with images : https://warehamforgeblog.blogspot.com/2019/10/fall-iron-smelt.html )

1) Clay is generally not found in Iceland. What few specific locations have only yielded a vary low melting point material, itself not suitable to withstand the normal operating temperatures within a bloomery furnace.
Excavations at Hals, Iceland exposed massive furnaces constructed of diagonally piled cut grass sod strips. These may (or may not ?) have had a thin liner of such clay, but the main support remains the sods. (see the earlier Hals series)
One of the furnaces at Skogar clearly indicates the remaining lower part of the furnace to be constructed of smaller stone blocks. As is most often the case, the entire upper portion of the furnace is missing.

2) http://warehamforgeblog.blogspot.com/2019/07/stone-block-furnace.html

3) ‘Towards an Icelandic Smelt’ An evaluation of the Hals site (Fall, 2008)
http://www.warehamforge.ca/ironsmelting/HALS/index.html

4)

5) http://www.warehamforge.ca/ironsmelting/ores.html