'Roman' - MoAF-I : Conclusions

Readers should refer back to recent postings on this topic :

the Mother of All Furnaces - Iron
'Roman' - MoAF-I : Results

What was learned?

1) Intake vs Exhaust vs Height
- The completed furnace, at 185 cm was certainly tall enough to allow for an effective drawing force into the stack.
- There were a number of factors that effected the relatively poor performance of the initial use of the MoAF - as a glass bead making furnace. Certainly one major factor on that first test was that the cross section ratio of intake ports to exhaust was certainly far too large. This may have been compounded by increasing the number of openings over the course of that burn.
- For the use of the same furnace body as an iron smelting furnace, the ratio conformed more closely to the theoretical model suggested by R.H. Rehder (1)
  Rehder's example was   1256 cm2 to 51 cm2 = 24.6 : 1
  MoAF-1 was          706 cm2 to 28 cm2 = 25.2 : 1

2) Charcoal Sizes
For the initial firing of this furnace, the charcoal was sized from .5 to 2.5 cm, our normal 'graded' fuel that has proved effective with our short stack iron furnaces.
With the MoAF-I experiment, this size was increased to 2.5 + / average 3.5 cm, as recommended by Rehder. This larger particle size proved effective in allowing air to flow upwards inside the furnace. Combined with the tall stack height, there was no problem maintaining the correct 'reaction time' for the falling ore, despite the larger gaps between individual fuel pieces.

3) Internal Temperatures
As can be seen on the temperature data, there proved to be no problem generating and maintaining the required temperatures to support the iron smelting process.

4) Type of Tuyere
The effectiveness of the mild steel pipe as tuyeres was a bit of a surprise, in terms of the lack of erosion / shortening of length over the entire burn. In the past, mild steel pipes have proven to melt off inside the smelting furnace, usually burning back towards the furnace wall. This in turn has resulted in excessive erosion of the furnace wall material itself - sometimes to the point of burning completely through!
The effect of the base height (below) may be an important variable here.

5) Base Height
Normally the position of the effective base of the furnace interior is controlled fairly carefully. Past experience has shown a space from base to tuyere of 10 cm is a minimum, with 15 cm the usual amount. This spacing is controlled by using charcoal fines or light wood ash packing in place. (This gap is required to leave room for the developing slag bowl, allowing accumulation of slag and the bloom - without 'drowning' the tuyere air blast).

For the MoAF-I experiment, it was decided to be very conservative in the placement of the tuyeres above the solid base of the furnace. The tuyeres were placed 20 cm above the base.
In the final analysis this large space proved to be an error. The slag bowl was found to form too low, dropping it down below the most effective heat zone inside the furnace. This in turn caused the partially sintered iron to cool below the effective 'welding temperature' needed to allow it to form into a solid bloom mass.

6) Ore?
Since the overall intent of this experiment was getting the needed temperatures, the actual addition of ore was almost an afterthought. Other project commitments had overwhelmed my available time to mix and properly dry a mix of our usual DD1 analog. So in the end we decided to make use of some materials on hand. This certainly proved to be of too low iron content, or not enough amount, to expect good bloom formation.

7) Bloom?
There certainly was effective reduction of iron oxide ores, with accumulation of the resulting iron metal. The overall lacy consistency of the resulting mass however does suggest a number of potential problems as the cause:
- Too small an amount of raw ore / of too low an iron content?
- Incorrect placement of the base below tuyere, cooling the iron below welding temperature to allow compaction?
- Generally a low air volume in the system, which has been shown in the past to result in both lower yields and less compact blooms.


Into the future?

At this point I have observed two other attempts at operating a full scale 'Roman' iron smelting furnace, 150 cm + internal diameter and 200 cm + taller. Neither of these attempts resulted in any effective iron production. There was a large amount raw materials required, and massive amount of expended labour for the construction. The amount of charcoal consumed was huge, with firings running days, rather than hours. All of this certainly beyond my resources here at Wareham.

The build for MoAF took a combined team of six, a full working day to construct. The materials required were over twice the amounts used for the typical 'short shaft' furnaces. As this particular firing was undertaken, the overall consumption of charcoal was in the same order as with the more complete sequence more typical.
It would likely prove quite possible to use ceramic 'flue' tiles for the upper stack portion of this type of furnace, which would speed construction considerably, and reduce materials costs.

Likely the most important factor that will influence continuing an experimentation series based on the Roman, passive tall stack builds was contributed by Neil Peterson:
'Just how many different historic periods do we want to investigate?'


1) 'The Mastery and Uses of Fire in Antiquity' by J.E. Rehder - 2000
McGill-Queen's University Press, ISBN 0-7735-2067-8 

'Roman' / MoAF-I : Results

(continues a rather lengthy post describing the furnace build)

One thing to remember here is that the intent of the Nov 3 experiment was to record internal temperatures = to see if high enough temperatures would be produced, and maintained, to allow for potential iron smelting.

In this, the effort can be seen as a success. Thanks to instrumentation provided by Neil Peterson, there was much better temperature data records than normally generated.

As detailed in the previous description, the addition of ore did not exactly follow our well proven 'best practice' :

•  There was no initial addition of iron rich slag, which has proven to quickly establish a working slag bowl system, increasing both yield and bloom density. (1)
•  The amount of ore added was on the small end. In the past it has been found that the first ore is primarily creating that same working slag bowl system, with the later amounts mainly contributing to iron mass on to the bloom. (2)
•  The quality of the bulk of ore used was questionable, with past uses of the same lot of material seen to result in low yields at best. (3)

A last important point was the overall layout of the base section of the furnace. The depth below tuyere level was set at 20 cm - intentionally quite deep. In the past it has been found that the most effective working range is 10 - 15 cm. If there is more available space to hard ground level, usually any extra is filled with charcoal fines. This was not done in this experiment. Primarily to negate the effect of accumulated ash and small charcoal pieces seen to be blocking air intake during the first firing of this furnace.

The following morning (so plus 16 hours), it was found that the charcoal had all burned away inside the furnace, but the exterior base was still warm to the touch. In actual fact, it would be another three weeks until the furnace was actually opened...

Nov. 3 - after cutting

The exterior of the MoAF-I furnace still remained in extremely good shape. There had been one major crack during the initial drying, which ran up to the lower of the two potential working ports cut for the bead making experiment. (This port can be seen, as sealed, roughly to the centre, left.) The intent for the November 3 experiment was to section the existing shaft, then lift off the top portion for conversion to a new 'short shaft' furnace. A starting cut was made 70 cm down from the top, using a zip disk on an angle grinder. The wall thickness proved to be about 6 cm - a bit deeper than the disk would cut. The last depth was cut with a small dry wall knife. A metal plate was slid through the cut, and the top section of the shaft carefully slid off and positioned on a prepared base plinth. (4)

View of interior, showing tuyeres with mass below

When the lower interior of the furnace was exposed, the heat effect on the clay was clear. The furnace walls were remarkably clean, with little attached slag or fragments of sintered iron attached. The individual tuyeres were still roughly the same length as when they were installed. There was considerable material fused and piled on top of each, what appeared as partially sintered (but reduced) iron, mixed with slag. There was considerable erosion effect to the tip of each of the tuyeres, now appearing to have the original mild steel pipe replaced by fused slag. They had however retained roughly their original insertion length of + 7 - 8 cm.
Judging from the heat effects, it appeared that the placement of the tuyeres was in fact quite effective in concentrating the heat into the centre of the furnace. (Rather than washing back on to the walls and erroding them, which likely would have been the case with a shorter insertion length.) (5)

Neil Peterson undertook the excavation of the furnace base. Recording the process was done through an extensive series of scaled photographs he made (only a few reproduced here).

Walls removed to about tuyere level (image by Neil Peterson)

Detail of lower left, before 'cleaning' (image by Neil Peterson)

The upper walls were cleared away, working down to tuyere level.
There was no clear bloom mass in evidence. The top surface was roughly bowl shaped, higher under each of the tuyeres and depressed to the centre. The material had a 'crumbly' surface texture, looking like reduced but only partially sintered iron with a lot of slag included. Unfortunately no exact measurement of the depth of this surface below tuyere level was made, but looking at the images, it appears to be about 6 - 8 cm lower to the centre.

One of the tuyeres removed (image by Neil Peterson)

In the image above, one of the tuyeres, with its attached debris, is positioned so the brick line is roughly the same as the furnace wall. The point of attachment through the wall is clearly visible. The congealed slag from the inner tip, will be in a vertical line (under gravity). Between the two indications, it is possible to find the original angle that the tuyere had been installed.

Another tuyere, image rotated to 'square' (image by Neil Peterson)

At least some indication of the minimum depth of the slag mass at the tuyere tip can be determined. The slag still attached to each tuyere forms a rounded 'drip' at its lowest end, so each had to have formed above that lower mass. The measured distances show at least 4 and 6 cm. (*)

After the tuyeres were removed, the remaining wall material was cleared down to expose the slag mass.

The slag mass exposed, surface cleaned

This surface was cleaned, first by brushing, then by using a tube to blow off ash from the fire and dust from breaking the walls.
In the image above, one further course of clay additions was been removed from the left side. You can clearly see the difference in heat effect. The upper level (closer to tuyere blast and thus the full furnace heat) shows slag attached to its inner surface. Clay shows sintering (white) from the inside outwards, carbonization of the horse manure organics, then dry baked clay to the exterior. In comparison, the next course down (just above the brick plinth) is only baked dry clay. The height difference between these layers is no more than 10 cm.

There was a clear 'necking' observed, with a change in appearance in the material above and below.

Mass exposed, side view - rotated to level (image by Neil Peterson)

The upper material formed a bowl shape, seen here to lift a good 6 - 7 cm towards the outer edges. The upper material had a thickness of about 7 - 8 cm at the centre down to the top of this reduction in diameter and change in material.

Slag mass removed, the right edge broke clear - image altered to place 'neck' at horizontal     (image by Neil Peterson)

With the lower mass completely pulled free of the furnace, the difference between the lower and upper sections was easily visible. One edge of the upper, lacy, material remained adhered to the clay walls, and broke free of the central mass (seen to right above).


Later in the day, the large mass was broken open (we still had hopes there might be an iron bloom inside...). The mass broke apart into several large chunks, and along the central 'neck' line.

Part of the lower, slag block (top uppermost)

As was expected, the lower section, below the 'neck' was one solid mass of iron rich slag. This was found to be almost totally free of charcoal or bubbles, a solid black colour of iron rich slag.

Upper mass - bottom side (against lower slag)

Upper mass - side towards tuyeres

The upper part (above the neck) had an entirely different construction. This proved to be lacy 'foils' of iron, formed around pieces of charcoal and containing a lot of slag. At best it appears only about 25% of this mass is actually iron. The 'foils' of iron can be seen as the white lines and spots in the images (especially in the bottom view).





next posting - Conclusions...


Prepared with some observation checking help from Neil Peterson.

1) What I call the 'Nissen Method'. This was demonstrated, to great result, by Danish experimenter Michael Nissen at the 2016 Pruszkowski Festival of Archaeology. In brief,3 - 5 kg of crushed iron rich tap slag is added as the first series of charges. This material will immediately form the effective slag bowl, so as ore is added after, it goes directly to iron bloom formation. Typically this method has been found to increase effective yields by about 10% (overall).

2) In relation to above. In the past it has been found (depending on ore type) that about the first 8 kg of ore goes into forming the working slag bowl system. Material added after that is generating bloom mass. This is especially true of those ore charges added to the end of the sequence. Our normal process here is to use roughly 30 kg of ore, with the expectation (with our DD analogs) of a bloom return of 20 - 25 % / 3 - 5 kg. Both raw size and yield % will sharply rise with larger ore additions. Remember that the overall intent of the various experimental series is primarily testing various furnace types and detailed builds - not production per se.

3) This specific ore lot was found to be generally 'poor' - with considerable slag, small blooms, and low yields, from earlier uses : Nov 5, 2006 / June 9, 2007 / Oct 27, 2007

4) Nov. 3 - 'Gromps' smelt. Report still pending.
One factor is that Neil proceeded to 'excavate' the MoAF-I furnace, while I was guiding a second team in preparing for a second experimental smelt. Both furnaces under the smelting area at Wareham, about 1 metre apart!

5) Through past experience, using higher volume air (bellows or electric blower), it has been found the 'sweet spot' for the tuyere tip is about 5 cm proud of the interior wall. When using mild steel pipe, these almost always will burn back to maintain that '+5 from wall' distance.

the ' Mother of All Furnaces - Iron '

or

'Roman' Passive Tall Stack

October 13 - 2018

The background to this experiment is a bit more contorted than usual.
My main smelting partner is Neil Peterson. His primary research area is Viking Age glass bead making, primarily the furnaces. In this there is even less archaeological evidence available than for iron smelting furnaces. (1)
One outstanding problem remains how to prevent excessive ash scarring on the surfaces of the beads produced using a number of potential furnace designs. This a problem we seem to encounter regularly, where the historic bead makers did not.

The latest in potential designs was to attempt a passive air system, based on the function of a 'tall stack'. Over a certain height (roughly 1.3 to 1.5 metres) the rising hot air will cause enough suction at the furnace base to ensure a constant draft, and effective burning of charcoal.

'The Mastery and Uses of Fire in Antiquity' by J.E. Rehder was our constant and best reference as we considered the possible designs for a 'Mother of All' scaled furnace. (2)

Our original intent was to take the standard 'short shaft' furnace built for the July iron smelting course here at Wareham (constructed by the crew of Hurstwic), and extend the height, roughly to double the normal height of 60 - 70 cm.

original plan

'Speaks with Fire' - end of smelt

As damaged...

But as it happened, I had a second major act of vandalism there at Wareham in early July, and the initial furnace, still in good shape after the iron smelt, was extensively damaged. (3)

So as it turned out, Neil and his bead team ended up constructing an entirely new furnace in later August. This was dried, then fired for the 'passive bead furnace' experimental test over September 1, 2018 - named 'the Mother of All Furnaces'.
In the end, the temperatures created where not as high, or as dependable, as hoped. In consideration after, this was most likely due to a simple error - of not leaving space *below* the air entry ports for the ash from the large quantity of charcoal burned to accumulate - without blocking those same air ports. There also was some questions that we might had of implemented Rehder's formulae on stack height / column cross section / air intake diameters even vaguely correct.

MoAF - after the bead furnace experiment

The basic MoAF bead furnace was 150 cm tall, with a cross section interior at 30 cm (with some variations). During the initial test, a metal collar had been added, increasing the entire stack height to 185 cm.
The highest temperature recorded was 940 C, but generally the furnace cycled through a lot of variation - and at lower peaks. Certainly the day long experiment had resulted in almost no damage at all to the interior or overall structure.

View down the interior of the furnace to the base, as seen before preparing the iron smelt experiment. (image by Neil Peterson)

As the image above shows, the internal temperatures of the initial firing only were high enough to just start sintering the clay into actual ceramic. The edges of the bricks supporting the furnace had some slag attached, with all the final charcoal fully reduced to ash, a layer about 2 - 3 cm thick.



Going back to Rehder, he gives an example of applying the (complex!) formulae to a theoretical passive tall stack furnace:

• - 40 cm ID / cross section .13 m2 (actually 1256 cm2)
• - 1.5 m stack height (above tuyere)
• - 3.5 cm average charcoal particle size 
• - 5096 mm2 tuyere cross section (so 51 cm2)
• - use of four tuyeres, each at 4.0 cm ID / with length of 20 cm  (4)

With the original MoAF burn, we had *not* run this math, but had relied on 'experience':

• - 30 cm ID / cross section .7 m2 (actually 706 cm2)
• - 1.5 to 1.85 m stack height (above tuyere)
• - .5 to 2.5 cm charcoal particle size (likely closer to 1.5 cm average)
• - 195 to 450 cm2 air inlet cross section (as rectangular openings in the base)
• - use of four to eight air inlets (altered by removing base bricks)

You can easily see that there were a large number of distortions from the system indicated by Rehder. One important question was : Did we actually make too large openings into the furnace, thus effectively reducing flow pressure into the stack?

So for the use of this furnace body for an iron smelt, we decided to conform more closely to Redher's example. Our cross section was fixed at 30 cm, which is 0.56 the area of the example. So we reduced our tuyere area by the same proportion.

• - 30 cm ID / cross section .7 m2 (actually 706 cm2)
• - 1.65 m stack height (above tuyeres)
• - 3.5 cm average charcoal particle size (described below)
• - 28 cm2 total tuyere cross section
• - use of four pipe tuyeres, each 30 mm ID / 18 cm long

As modified - MoAF-I

The charcoal sizes used were greatly increased. On some consideration, it was most likely that the small particle sizes used on the initial burn did not allow enough spaces for the effective passage of air through the system. Our normal practise is to take the raw bagged charcoal, then break it up with mallets over a 2.5 cm grid. This is passed over a second, smaller screen at roughly 0.5 cm (1/4") to screen out the fines. In preparing the fuel for the iron smelt, the rough was screened (not broken) using the upper grid only. This material thus had a lower size of 2.5 cm, with some pieces as large as 10 cm or more - in all hopefully conforming to the suggested 3.5 cm average.

Although not indicated in the layout drawing, the four tuyeres were placed to leave a roughly 20 cm height above the hard ash base. The tuyeres themselves were cut lengths of standard 'schedule 40' mild steel pile, so with a wall thickness of roughly 3 mm (1/8 ")

from the top, showing tuyere placement (image by Neil Peterson)

The four tuyeres were set at rough quarters around the circumference. Each was set so it would extend about 1/4 the way towards the centre of the furnace, a depth of about 7 - 8 cm. The intent here was to create as even a 'bubble' of air into the furnace volume as possible. The standard 22.5 down angle proven effected in earlier smelts was utilized for each.

There was better instrumentation on hand for this experiment. Neil had invested in a multi-input data recorder, linked to a computer lap top. A total of three small ports were drilled into the furnace wall, at + 10 / + 20 / +50 above tuyere level. High temperature thermocouples were installed in each, pushed into the furnace body about 10 cm past the interior surface. Linked to the data recorder system, this made for temperatures noted every 10 seconds over the main part of the firing sequence.

Showing the location of the temperature probes, one of the tuyeres is clear to the lower right.  (image by Neil Peterson)

 

 In addition, one larger circular viewing port was cut, on to the 'back' of the furnace (directly opposite of the position of the probes). This was set at 45 cm above tuyere level. The port was plugged with a removable cylinder of clay.

During the split wood pre-heat cycle.

As the furnace had already gone through a full firing cycle, the clay body was 'bone dry' and the normal pre-heating with small wood splints could be shortened, to roughly 45 minutes.
The first charcoal was added, initially only to the roughly +50 cm level. The side observation port proved of value here. For roughly the next hour, single buckets of charcoal were added, while the internal temperatures were monitored. (5)
It quickly became apparent that the probe inserted at +20 was giving inaccurate, consistently too low, readings. 
The exact burn rates in this period were hard to keep consistent, but this was as much because of the difficulty of determining the exact charcoal level as anything else.

After filling with charcoal - obviously incomplete combustion.

The internal temperatures certainly indicated that starting into the second hour after the addition of charcoal, the lower (reactive column ) area of the furnace was certainly reaching, and maintaining, 'smelting temperatures' of + 1100 - 1200 C.
It was decided at roughly + 1 hour 20 minutes to completely fill the tall stack. This was expected to 'crash' the temperatures, at least for a short time - and this is clearly seen in the temperature data.

At two hours into the main charcoal sequence, it was decided to start with ore additions (so roughly 35 minutes after fulling the whole stack to the top).
The main objective of this experiment was to see if and effective arrangement of tuyeres could create the high temperatures needed for actual iron smelting. In many ways this cause the actual production of a quality bloom was secondary. Although we were well aware of the 'Nissen Method' of adding a quantity of iron rich tap slag as the first charges (to quickly establish the working slag bowl), no slag was available to allow this step. Rather than use the well proven DD1 analog, some smaller amounts of other ore bodies on hand were used. In the end a total of 13 kg of 'Lexington Brown' limonite made up the main charges - an ore body shown to be lower in iron content. (6) There was a small amount of the DD1A analog, total of 5.8 kg, which was added as the final charges.
Once the whole stack was filled, the addition rate for a standard 1.8 kg bucket increased to an average of 30 minutes. It was decided that because of the known 'mixing effect' of the tall stack, larger ore charges would be added than usual. Here individual charges were initially 2 kg, later 3 kg each. (7)

'Down the Kilt' shot - through a tuyere at the later part of the smelt

Observations down the tuyeres certainly confirmed that iron ore was being reduced and was at suitable temperatures at the bottom of the furnace.
After the last addition of ore, the furnace was left to simply operate on its own. We calculated it would easily take another four hours to completely burn down.


(to come ... dismantling and results)


1) Iron smelting sites are both plentiful and distributed throughout the Norse homelands and their various expanded settlement regions. Although furnace remains tend to be just the base sections, these do indicate a number of construction variations on the basic 'Norse short shaft' type. (This the effect of locally available building materials primarily).
Actual Viking Age / Norse glass bead manufacturing sites, on the other hand, are quite limited - basically with only seven locations showing remains of bead making. Of these, only Ribe in Denmark contains remains that might be those of actual bead making furnaces themselves.
Neil has been undertaking a long campaign of experiments to attempt to build an effective (and efficient) small, charcoal fired, and bellows activated, bead making furnace. This work has been documented through a number of academic papers and presentations, as well as extensively on the DARC web site :
'Viking Age Bead Making'

2) This volume was published in 2000. I was presented a copy in 2007, which admittedly I did not read until much later. Although very much an academic treatment, and thus a bit hard for the more practical worker to sort through, there most certainly is a wealth of information presented. The volume covers the theory of operation of a wide range of historic furnace types - used for ceramics, glass and various metals. (A bit more study on my own part might have saved a *lot* of mis-steps over my own experiments!)
McGill-Queen's University Press, ISBN 0-7735-2067-8 

3) The result of this was the loss of roughly $50 in raw materials, but more importantly - roughly 16 plus 'man hours' of hard work. The report on file with the OPP gives the loss at $500.

4) example given on page 182

5) You will find the temperatures on the data have been colour coded :

•  + 1000 - 1050 C = light yellow
•  + 1050 - 1100 C = dark yellow
•  + 1100 - 1150 C = light orange
•  + 1150 - 1200 C = dark orange
•  + 1200 - 1250 C = light grey
•  + 1250 - 1300 C = dark grey 

The temperatures between 1100 - 1200 C are considered 'ideal' for the iron smelting process.

6) This material was some I had gathered back in 2006, with the assistance of Vandy Simpson. Although the area around Lee Sauder's home base outside Lexington Virginia most certain contains some very good quality limonite ore, the relative (lack of) skill of the gathering needs to be remembered. The last use of this material dates back to the 2007 - 2008 period, all the uses of this ore ended up with low yields.

7) Another factor here was the raw time - and old bones. This was the second iron smelt we had undertaken inside of four days! With charcoal additions at 30 minutes, combined with a later start, time was approaching 5:30 pm. Neil and I decided that 'proof of concept' was all this experiment was really intended. To that end, we basically used all the prepared ore we had on hand, rather than attempt the more usual 30 kg ore amounts normally used.

Canada, Carbon Tax, and the Blacksmith

This past week (Tuesday October 23) the Government of Canada announced the long expected rates for Carbon.

Now I have commented about this whole situation before on this blog :
Carbon and the Forge : July 7, 2008
Carbon Loading : Dec. 14, 2015
Carbon Loading at Wareham : March 8, 2018
(related)
Don't Call US : March 12, 2018

I have said repeatedly that I fully understand :
• the direct impact burning fossil fuels on Climate
• the responsibility users have for their own actions
• I am a direct user of quantities of fossil fuels in my forges (coal, propane)

I fully support the concept of a direct cost to all users for the amounts of carbon / greenhouse gasses they create. 
My intent here is to offer up some kind of cost estimates for other artist blacksmiths.

Here is the current plan as currently published by the Government of Canada (1) :

"Starting in April 2019 and increasing in stringency over time, the federal pollution pricing system will add a nominal cost to everyday fuels."

"The fuel charge rates reflect a carbon pollution price of $20 per tonne of carbon dioxide equivalent (CO2e) in 2019, rising by $10 per tonne annually to $50 per tonne in 2022."

 

Type	Unit	Apri1 2019	Apr-20	Apr-21	Apr-22
	($ per)	($20/tonne)	($30/tonne)	($40/tonne)	($50/tonne)
Propane *	litre	0.031	0.0464	0.0619	0.0774
	per 40 lb	$0.98	$1.47	$1.96	$2.45
	WF use @ 365kg	$19.69	$29.46	$39.31	$49.15
High heat value coal	metric tonne	45.03	67.55	90.07	112.58
Low heat value coal		35.45	53.17	70.9	88.62
	per 75 lb	$0.77	$1.15	$1.53	$1.92
	WF use @450kg	$10.13	$15.20	$20.27	$25.33
Gasoline	litre	0.0442	0.0663	0.0884	0.1105
	WF use @ 3000 L	$132.60	$198.90	$265.20	$331.50
Aviation turbo fuel	litre	0.0516	0.0775	0.1033	0.1291

Quotes and Numbers from the Official Government of Canada web site :

https://www.fin.gc.ca/n18/data/18-097_1-eng.asp

- I have used the larger cost for 'high heat coal' as these types are not clearly defined in the Government table. (I use mid range bituminous, not higher range anthracite)
- I have included the figures given on aviation fuel here. Right now I appear to be making a trip to Aberdeen, Scotland every second year. Obviously there will be some increase involved (2)
- The Wareham Forge (WF) costs are listed first as the typical purchase unit, and as a roughly average yearly total.
* Propane figures represent the biggest juggling here (and may thus be prone to error!). The GC site gives the rates as per litre. I purchase as standard 40 lb cylinders. Most carbon use tables work in KG (or some horrible mash of units).



1) Ontario's current ruling Conservative Party, especially Premier Doug Ford, has vowed to fight the Government of Canada on all policies related to Carbon / Climate Change. They have to date cancelled any number of programs originally put in place by the previous Liberal government here.

2) Obviously figuring out how a 5 - 11 cent per litre increase on aviation fuel will impact on international air travel costs is almost impossible to figure. (I was surprised to find the current cost of av gas is actually considerably cheaper than regular gasoline!)