From a discussion off NORSEFOLK:
" ... The lefty (being the minority) is accustomed to fighting opposite-handed
people. The righty, however, is usually used to fighting mainly (if not
only) other right-handed fighters. Therefore, the left-handed fighter is going to have an advantage. ... "
~Valinn
Going back to the artifacts, what is found is never complete (usually hilts rotted off) or in good enough preservation (blades corroded) to be able to gather much raw information.
Although swords in the VA are the symetrical broad sword type, there should in fact be a slight wear difference between the inside and outside cutting edges. In normal use the blade would be drawn, used, then returned to the scabbard in roughly the same position. A double edge does give you a second cutting surface that you could rotate into position if the primary edge was dulled in use. (Also an edge available for a backhand stroke without rotating the wrist.) Truth is that you do have a tendancy to use the same edge all the time.
On a sword with long life and much use (refer back to the sword as family heirloom idea) there should in fact be a slight difference in profile on the master edge from all the sharpening. (That would be the side that points to the centre of your body when you held the sword naturally, palm towards your stomach.) This would be a different side of the blade for right versus left master hand. Again a weapon with an extremely long life may have the hilt worn into patterns by consistant grip in the same hand.
As an example of this, but far more pronounced - ask any long time blacksmith if you can look closely at their primary forging hammer. The head will actually be worn away in a manner that is dictated by oth 'handedness' and their individual working style (largely determined by body type and things like anvil position).
The sad truth is that there is little work done on skeletons themselves in terms of looking at wear patterns caused by work. Right or left handedness will clearly mark the bones. (This lack of research is pretty frustrating to those of use interested in tool use.) So what we have here is no way to gather clear information from either artifact or body remains.
Consider some related cultural traditions:
If I remember correctly, the Roman army considered the position of 'file closer' one of honour. Read that as 'experience'. You put your best and most experienced fighter on the right end of file. This because he would have his exposed sword arm open against a flanking move by the enemy (rather than shield side as on the left end). This custom is maintained up to the modern era by the way,. At least on the parade ground the sargent is placed to the right front of a group. If you had a left hander - that is certainly where you placed him. (This certainly was my own Pensic experience, for what that is worth.)
Into the middle ages properly, left handers are subject to discrimination - based on their quite real combat advantage as Michael states above. You were thought 'sinister' (remember all that healdry!).
Again this continued up to the modern day - I certainly am old enough to remember kids being punished when they tried to write with their left hands.
A fast last note - on Norse swords having no right or left hand grips.
When I am making swords for myself, I almost always fit them with a 'semi orthopedic' grip. I pick a piece of antler that feels good in my (right) hand, then work it down until it is truely comfortable. I have relatively small hands, with the bumps and knobbs of a life as blacksmith. Others have commented that they find the grip quite UNcomfortable. Of course these grips have very clear right and left sides to them.
Now, in the sagas and legondary stories, you often find the plot device of the magic or family sword which is stolen. When the villan attempts to use the sword against its original hero owner you read a line like 'the sword twisted like a live thing'. This is exactly the effect of attempting to use such a custom fitted sword if your hand is the wrong size. I see this as art dressing up a very real situation.
Now I would expect MOST swords to have universal grips. Both because it makes it easier to utilize both cutting edges and also because most sword users are not sword makers. Just a piece of historical trivia to throw into the pot.
Sunday, March 25, 2007
Saturday, March 17, 2007
Now with ISBN
1) Introduction to Blacksmithing (DVD) = ISBN 978-0-9783284-0-5
2) Historic Bladesmithing (DVD) = ISBN 978-0-9783284-1-2
3) Forging the Viking Age (DVD) = ISBN 978-0-9783284-2-9
4) Experimental Iron Smelting from the Viking Age (CD-ROM)=
ISBN 978-0-9783284-3-6
It turns out it is possible for a Canadian 'self publisher' to register through the Archives of Canada. This gives you a ISBN publisher number. You then can register individual publications for a unique ISBN - which includes DVD / audio CD / CD-ROM
http://www.collectionscanada.ca/6/11/index-e.html
What I also found interesting is that the whole thing was done on-line and was free - the Canadian Government is picking up any costs involved. Against this they ask that two copies of the works registered are sent for their standing collection. This also ensures a durable record of the work.
2) Historic Bladesmithing (DVD) = ISBN 978-0-9783284-1-2
3) Forging the Viking Age (DVD) = ISBN 978-0-9783284-2-9
4) Experimental Iron Smelting from the Viking Age (CD-ROM)=
ISBN 978-0-9783284-3-6
It turns out it is possible for a Canadian 'self publisher' to register through the Archives of Canada. This gives you a ISBN publisher number. You then can register individual publications for a unique ISBN - which includes DVD / audio CD / CD-ROM
http://www.collectionscanada.ca/6/11/index-e.html
What I also found interesting is that the whole thing was done on-line and was free - the Canadian Government is picking up any costs involved. Against this they ask that two copies of the works registered are sent for their standing collection. This also ensures a durable record of the work.
Friday, March 16, 2007
Experimental Iron Smelting Disk Released
Experimental Iron Smelting from the Viking Age (CD-ROM)
ISBN 978-0-9783284-3-6
Official release - March 15, 2007
http:www.warehamforge.ca/ironsmelt.html
ISBN 978-0-9783284-3-6
Official release - March 15, 2007
http:www.warehamforge.ca/ironsmelt.html
This disk is the revision of the earlier 'Iron Smelting in the Viking Age' (released in 2004). The new disk contains the information on the experimental smelts up to November 2006. This represents a substantial increase, with as many smelts undertaken in 2006 alone as in
all the years previous. The collection now details over 22 smelts, as
well as new supporting materials. An important contribution is the full
content of the Dark Ages Re-creation Company web site documentation
designed and largely written and photographed by Neil Peterson. This
section makes up a mere fifth of the new total, which combined amounts
to roughly 660 megabytes of data! There are now almost 2000 images, most
as large detailed 16 x 20 size. Each smelting experiment also includes
the data detailing the smelt sequence, plus field drawings of the
smelter set up.
The disk also includes an overview of the three Early Iron
Symposiums to date (2004 - 2006). In keeping with my involvement with
Early Iron, the disk includes detailed instructions on the construction
and firing for two simple test smelters. The 'Econo Norse' smelter was
developed by DARC, and instructions for using the 'Flue Tyle' smelter
have been provided by Skip Williams.
Although the experiments are not generally formatted with
conclusions, there are comments accompanying the most of the
photographs. Of interest to more academic researchers may be 'Adventures
in Early Iron Production' a formal paper I presented at the 'Friends of
the Medieval Studies Society of the Royal Ontario Museum' 1st Annual
Symposium in March 2006.
Much has been learned. On a good day, it now is most likely that
when the furnace is opened at the end of the smelt there will be a
workable iron bloom resting down inside. Much valuable experience has
been gained towards developing a predictable sequence for a successful
smelt. An understanding is being learned of just what sights and sounds
are significant, of which elements may help or hinder the outcome. The
series has stepped back from the first stumbling attempts, with more
dependable modern equipment replacing largely speculative historic
re-creations. Now that iron can be produced with reasonable certainty,
the next challenge will be to slowly replace all the modern tools with
their historic counterparts. The adventure continues!
The creative advice and shared experience of a number of
individuals have helped me gain a better understanding of turning 'dirt
into metal'. I have done my best to credit those ideas and inspirations
contributed by others - the disk contains a detailed set of
acknowledgments. Certainly my own understanding would have remained
limited without the guidance and friendship of Lee Sauder, Skip Williams
and Mike McCarthy. The sequence of experiments would have simply been
impossible without the team spirit and physical efforts of the other
members of DARC. Especially this applies to the core smelt team of Neil
Peterson, Dave Cox and Kevin Jarbeau, who also feature so prominently in
the images.
Darrell
all the years previous. The collection now details over 22 smelts, as
well as new supporting materials. An important contribution is the full
content of the Dark Ages Re-creation Company web site documentation
designed and largely written and photographed by Neil Peterson. This
section makes up a mere fifth of the new total, which combined amounts
to roughly 660 megabytes of data! There are now almost 2000 images, most
as large detailed 16 x 20 size. Each smelting experiment also includes
the data detailing the smelt sequence, plus field drawings of the
smelter set up.
The disk also includes an overview of the three Early Iron
Symposiums to date (2004 - 2006). In keeping with my involvement with
Early Iron, the disk includes detailed instructions on the construction
and firing for two simple test smelters. The 'Econo Norse' smelter was
developed by DARC, and instructions for using the 'Flue Tyle' smelter
have been provided by Skip Williams.
Although the experiments are not generally formatted with
conclusions, there are comments accompanying the most of the
photographs. Of interest to more academic researchers may be 'Adventures
in Early Iron Production' a formal paper I presented at the 'Friends of
the Medieval Studies Society of the Royal Ontario Museum' 1st Annual
Symposium in March 2006.
Much has been learned. On a good day, it now is most likely that
when the furnace is opened at the end of the smelt there will be a
workable iron bloom resting down inside. Much valuable experience has
been gained towards developing a predictable sequence for a successful
smelt. An understanding is being learned of just what sights and sounds
are significant, of which elements may help or hinder the outcome. The
series has stepped back from the first stumbling attempts, with more
dependable modern equipment replacing largely speculative historic
re-creations. Now that iron can be produced with reasonable certainty,
the next challenge will be to slowly replace all the modern tools with
their historic counterparts. The adventure continues!
The creative advice and shared experience of a number of
individuals have helped me gain a better understanding of turning 'dirt
into metal'. I have done my best to credit those ideas and inspirations
contributed by others - the disk contains a detailed set of
acknowledgments. Certainly my own understanding would have remained
limited without the guidance and friendship of Lee Sauder, Skip Williams
and Mike McCarthy. The sequence of experiments would have simply been
impossible without the team spirit and physical efforts of the other
members of DARC. Especially this applies to the core smelt team of Neil
Peterson, Dave Cox and Kevin Jarbeau, who also feature so prominently in
the images.
Darrell
Wednesday, March 14, 2007
This is aimed mainly at Bill's comments on the heat treating posting. I think the general readers may find our experiences of interest. If you have not read his comment to the last post - you certainly should then come back here...
Anyway:
I got a lot of the theory behind heat treating that I know from a lecture by Philip Baldwin of the New England Guild of Bladesmiths - years back. Phil is certainly one of the top layered steel makers in North America, if not the world. He also not only understands the science, he was able to reduce it down to practical advice.
The ideal quenching oil would have an extremely high vapor point. That would allow it to pull heat away without bubbles, which leave voids that result in uneven cooling. The historically preferred medium was actually whale oil. Modern quenching oils are basically synthetic whale oil (!) He said that they had found bacon fat rendered to grease a good subsitute, but also mentioned the stench. he also recommended a fine cooking oil like cannolla or olive oil.
I personally have had good results with new 10 W 30 motor oil. Thats both for 1045 spring steel for swords and long blade tools, inset edges on axes and 1095 on short knives. I usually also use this oil on the layered steels. I personally have not used the 5% salt. I do know that Lloyd Johnson has mentioned using molten lead for certain tasks (never tried that one either).
I would stress that the function of the tool, the metal chosen and the quenching medium have all got to work together in balance to create the desired effect in the final object.
Bill said:
"When I get swords made for me, a professional heat treating company in Montreal will harden them, then dip them in salt to drag them down to Rockwell 50 to 51. They usually come back to me all warped and twisted. One in ten is un-recoverable. I had to learn how to straighten out a hardened and tempered tool."
Geezz - get a new heat treating service! They are obviously doing something very wrong. If you have correctly annealed the blades (or are paying them to do this) there should be NO warps. I'd almost be certain they are quenching the blades by laying them flat down into the liquid. Swords should ALWAYS be quenched point first. This takes a special container to be made up. I use a piece of 6" wide ABS plastic pipe with a sheet metal liner. It holds about 3 gallons of oil, and is a pain to hold and empty. I have never had any problems with warping (and certainly never twisting) on any of my forged blades. (We will leave aside the pattern welded blade that shattered - that was an entirely different problem!)
Darrell
Anyway:
I got a lot of the theory behind heat treating that I know from a lecture by Philip Baldwin of the New England Guild of Bladesmiths - years back. Phil is certainly one of the top layered steel makers in North America, if not the world. He also not only understands the science, he was able to reduce it down to practical advice.
The ideal quenching oil would have an extremely high vapor point. That would allow it to pull heat away without bubbles, which leave voids that result in uneven cooling. The historically preferred medium was actually whale oil. Modern quenching oils are basically synthetic whale oil (!) He said that they had found bacon fat rendered to grease a good subsitute, but also mentioned the stench. he also recommended a fine cooking oil like cannolla or olive oil.
I personally have had good results with new 10 W 30 motor oil. Thats both for 1045 spring steel for swords and long blade tools, inset edges on axes and 1095 on short knives. I usually also use this oil on the layered steels. I personally have not used the 5% salt. I do know that Lloyd Johnson has mentioned using molten lead for certain tasks (never tried that one either).
I would stress that the function of the tool, the metal chosen and the quenching medium have all got to work together in balance to create the desired effect in the final object.
Bill said:
"When I get swords made for me, a professional heat treating company in Montreal will harden them, then dip them in salt to drag them down to Rockwell 50 to 51. They usually come back to me all warped and twisted. One in ten is un-recoverable. I had to learn how to straighten out a hardened and tempered tool."
Geezz - get a new heat treating service! They are obviously doing something very wrong. If you have correctly annealed the blades (or are paying them to do this) there should be NO warps. I'd almost be certain they are quenching the blades by laying them flat down into the liquid. Swords should ALWAYS be quenched point first. This takes a special container to be made up. I use a piece of 6" wide ABS plastic pipe with a sheet metal liner. It holds about 3 gallons of oil, and is a pain to hold and empty. I have never had any problems with warping (and certainly never twisting) on any of my forged blades. (We will leave aside the pattern welded blade that shattered - that was an entirely different problem!)
Darrell
Sunday, March 11, 2007
Viking Age SWORDS - part 3 - HEAT TREATING
Sorry there has been a delay here. I prepared this for NORSEFOLK - and forgot to post it here!
The next part of this overview is the mysterious part - Heat Treating. (As Kettil I would NEVER discuss this with you!)
From our earlier discussion, we can see that the sword maker, modern or ancient, has made decisions about what metals to incorporate into the blade. An understanding of the handling characteristics of the tool has been filtered through technical specifications and working methods to decide upon some 'ideal' alloy, or combination of alloys to form into the final profile of the sword.
There could be a long discussion (read argument) over traditional hot forging versus modern machine working methods. I'm going to completely side step that one. My only statement will be this: Understand that the differing alloys are best suited to certain fabrication methods. Some modern alloys are virtually impossible to hand forge, but still produce excellent results when machined to shape.
Now, any specific carbon content iron alloy can further be modified by just how you heat and cool it. One of the Ancient Mysteries is how a skilled smith can take the same piece of metal, and by cooling it one way make it soft enough to bend back on itself, yet treat it another way and it becomes so hard that it shatters when dropped on the floor. Physically what is happening is that specific sequences of temperature and cooling rates change the way the underlaying crystal structure develops at a microscopic (even atomic) level. There are three fundamental sequences to the overall heat treating of carbon alloys: Annealing, Hardening, and Tempering.
Annealing is the first step, done right after the blade has been rough formed. It is most important to be undertaken in any blade that has been forged (hammered - hot or cold). The metal must first be heated up to past 'critical' , at least to a dull red . At this point the crystals in the metal loose their definition, the component atoms start to loose their tight bonds with each other and become somewhat 'slippery'. If the metal is then allowed to cool very slowly, the end result is that the material will become as soft as it can get (dependent on the actual other elements in the specific alloy). Any stresses built up into the structure during the hammering process will ease away. Imagine giving yourself a long soak in a hot tub. A rough rule of thumb is that the longer the metal takes to cool down from critical, the softer it can become. (Of course remember that the exact alloy content determines the base level.)
As any forged blade will require considerable grinding to even up and clean the surface, softening the metal makes that next process easier. The blade blank is ground to shape, with any holes for things like hilt pins made. It will then be polished to 'close' to the final finish desired.
Hardening the material is almost the exact opposite. Again the blade is heated to critical, loosening the bonds and thus allowing changes to be made. Now the metal is quickly cooled. Imagine jumping from that hot tub into cold water. In rough terms, the faster the metal is cooled from critical, the harder it will become. Again remember there is a maximum possible as determined by the alloy chosen in the first place. Now differing quenching mediums will pull heat at different rates. As a rough order from slower to quicker - on liquids available to the Norse : oil / water / salt water. So it is possible to take the same carbon content metal and change its relative hardness depending on how you cool it.
Generally the tang is left in its original annealed (soft) state and only the blade is quenched.
It should be noted that modern alloys can be extremely exotic in the required quenching mediums. The simplest will actually harden in air. There are those that require slow liquid salt baths through to instant cooling in liquid nitrogen. (All too weird for me!)
A couple of interesting historical notes:
The ideal oil for quenching would heat quickly and evenly. It would have a very high vapor point - thats the temperature where the oil flashes to gas. (Bubbles of gas pull heat at a much lower rate than liquid does, so can give uneven cooling effects. Now it turns out just about the best oil in terms of its physical characteristics (so I have read) is * whale * oil. Not exactly available to modern blade makers, but modern quenching oils are very like a synthetic whale oil. Again I have it on good authority that rendered bacon fat yields good results. Any high quality cooking oil works effectively as well.
Consider salt water at roughly 5% salt content. Ocean water varies considerably from place to place and season to season. What does remain much more consistent in terms of salt content is blood. This is the science behind the myth of the blade 'quenched inside a human body'. (Actually using a living body to quench a red hot sword blade will ABSOLUTELY NOT WORK, by the way!)
It should be mentioned here that the process of heating to critical for hardening also creates a thin film of scale on the blade surface. Now you have to repeat that last polishing step to clean down to bare metal again. Only this time with extreme care. The blade has been made as hard all over as may be required. Hard almost always means brittle. If you drop it at this point (or more commonly the sander tries to grab it out of your hands!) it may shatter. More importantly, the last heat treating step is a LOW temperature one. If you over heat the blade even slightly during the required polish now, you have to go all the way back to the anneal step. (Thats repeat : heat / slow cool / POLISH / heat / quench/ POLISH)
TEMPERING is the last of the three heat treating steps. The common perception of this process is totally wrong. Tempering is actually REMOVING hardness in a selective fashion. Remember we have selected a possible range of hardness by picking a specific carbon content in the metal. We then have fixed the maximum hardness in the blade overall by the cooling speed of the quenching medium.
Consider that different parts of a blade perform different functions, and ideally should have different characteristics in a correctly designed weapon. In the perfect blade, the point / edge / back (or centre in double edged) and tang all undertake different stresses and thus should have different amounts of hardness against flexibility. Generally the point is extremely hard, the edge very hard, the back somewhat soft and the tang dead soft. Since hardening sets the maximum hardness, the blade maker has defaulted to what is required for the point. Now some of the hardness must be removed from the cutting edge (lest it remain too brittle) and especially the back / core (to allow flexibility).
Tempering is undertaken by carefully heating the blade in as controlled a fashion as possible. Changes in the component crystal structure will start to occur once the metal is heated to roughly 450 F. In practice, an extremely thin film of oxide starts to form on the polished metal, which can be seen as a progression of colours over the surface. The range from cool through to hottest is : Yellow / straw / brown / red / purple / blue / grey. At roughly 800 F the metal passes beyond the temper range and develops the solid grey iron oxide. Once the ideal combination of colours (thus temperatures) is observed, the blade is quickly quenched to 'freeze' the varied hardnesses in place. Depending on just what method is used to heat the blade when tempering, those temperature colours can develop extremely fast. If an error is made and the metal gets too hot, then the blade maker ** should repeat the entire heat treating process at the initial annealing phase **. One last surface polish remains to remove the thin oxide film before the blade goes on to be hilted.
Just what temperature / temper colour should be created just where on a given blade can vary considerably. Use of the blade, alloy selected, hardening degree, all will relate to the way the blade is finally tempered.
Most commercial knife makers will in fact avoid the skills involved and simply oven temper their blades. An average is determined, again based on the dynamics of the alloy and quenching. Then an electric kiln is set to a specific temper range and the entire blade is fixed at an average degree of hardness. Although use of more complex alloys can help give decent results, the simple truth is that an oven tempered blade will never perform as well a correctly eye tempered one.
(Note * correctly * !! Hand forging and eye tempering a blade requires a significant amount of acquired skills, knowledge and experience to create what can be a superior finished result. Its also easy to screw it up. All that accumulated practice comes with a cost. Machine ground and oven heat treated blades can expected to be uniform in quality and certainly much cheaper to produce.)
As I said when the topic of knives came up a while back - you get what you pay for...
Darrell
PS - I've intentionally left a lot of practical details out of this general description. Sorry, but I do earn a living from courses I teach on these subjects. I also recommend my DVD - "Historic Bladesmithing" - available on my web site.
The next part of this overview is the mysterious part - Heat Treating. (As Kettil I would NEVER discuss this with you!)
From our earlier discussion, we can see that the sword maker, modern or ancient, has made decisions about what metals to incorporate into the blade. An understanding of the handling characteristics of the tool has been filtered through technical specifications and working methods to decide upon some 'ideal' alloy, or combination of alloys to form into the final profile of the sword.
There could be a long discussion (read argument) over traditional hot forging versus modern machine working methods. I'm going to completely side step that one. My only statement will be this: Understand that the differing alloys are best suited to certain fabrication methods. Some modern alloys are virtually impossible to hand forge, but still produce excellent results when machined to shape.
Now, any specific carbon content iron alloy can further be modified by just how you heat and cool it. One of the Ancient Mysteries is how a skilled smith can take the same piece of metal, and by cooling it one way make it soft enough to bend back on itself, yet treat it another way and it becomes so hard that it shatters when dropped on the floor. Physically what is happening is that specific sequences of temperature and cooling rates change the way the underlaying crystal structure develops at a microscopic (even atomic) level. There are three fundamental sequences to the overall heat treating of carbon alloys: Annealing, Hardening, and Tempering.
Annealing is the first step, done right after the blade has been rough formed. It is most important to be undertaken in any blade that has been forged (hammered - hot or cold). The metal must first be heated up to past 'critical' , at least to a dull red . At this point the crystals in the metal loose their definition, the component atoms start to loose their tight bonds with each other and become somewhat 'slippery'. If the metal is then allowed to cool very slowly, the end result is that the material will become as soft as it can get (dependent on the actual other elements in the specific alloy). Any stresses built up into the structure during the hammering process will ease away. Imagine giving yourself a long soak in a hot tub. A rough rule of thumb is that the longer the metal takes to cool down from critical, the softer it can become. (Of course remember that the exact alloy content determines the base level.)
As any forged blade will require considerable grinding to even up and clean the surface, softening the metal makes that next process easier. The blade blank is ground to shape, with any holes for things like hilt pins made. It will then be polished to 'close' to the final finish desired.
Hardening the material is almost the exact opposite. Again the blade is heated to critical, loosening the bonds and thus allowing changes to be made. Now the metal is quickly cooled. Imagine jumping from that hot tub into cold water. In rough terms, the faster the metal is cooled from critical, the harder it will become. Again remember there is a maximum possible as determined by the alloy chosen in the first place. Now differing quenching mediums will pull heat at different rates. As a rough order from slower to quicker - on liquids available to the Norse : oil / water / salt water. So it is possible to take the same carbon content metal and change its relative hardness depending on how you cool it.
Generally the tang is left in its original annealed (soft) state and only the blade is quenched.
It should be noted that modern alloys can be extremely exotic in the required quenching mediums. The simplest will actually harden in air. There are those that require slow liquid salt baths through to instant cooling in liquid nitrogen. (All too weird for me!)
A couple of interesting historical notes:
The ideal oil for quenching would heat quickly and evenly. It would have a very high vapor point - thats the temperature where the oil flashes to gas. (Bubbles of gas pull heat at a much lower rate than liquid does, so can give uneven cooling effects. Now it turns out just about the best oil in terms of its physical characteristics (so I have read) is * whale * oil. Not exactly available to modern blade makers, but modern quenching oils are very like a synthetic whale oil. Again I have it on good authority that rendered bacon fat yields good results. Any high quality cooking oil works effectively as well.
Consider salt water at roughly 5% salt content. Ocean water varies considerably from place to place and season to season. What does remain much more consistent in terms of salt content is blood. This is the science behind the myth of the blade 'quenched inside a human body'. (Actually using a living body to quench a red hot sword blade will ABSOLUTELY NOT WORK, by the way!)
It should be mentioned here that the process of heating to critical for hardening also creates a thin film of scale on the blade surface. Now you have to repeat that last polishing step to clean down to bare metal again. Only this time with extreme care. The blade has been made as hard all over as may be required. Hard almost always means brittle. If you drop it at this point (or more commonly the sander tries to grab it out of your hands!) it may shatter. More importantly, the last heat treating step is a LOW temperature one. If you over heat the blade even slightly during the required polish now, you have to go all the way back to the anneal step. (Thats repeat : heat / slow cool / POLISH / heat / quench/ POLISH)
TEMPERING is the last of the three heat treating steps. The common perception of this process is totally wrong. Tempering is actually REMOVING hardness in a selective fashion. Remember we have selected a possible range of hardness by picking a specific carbon content in the metal. We then have fixed the maximum hardness in the blade overall by the cooling speed of the quenching medium.
Consider that different parts of a blade perform different functions, and ideally should have different characteristics in a correctly designed weapon. In the perfect blade, the point / edge / back (or centre in double edged) and tang all undertake different stresses and thus should have different amounts of hardness against flexibility. Generally the point is extremely hard, the edge very hard, the back somewhat soft and the tang dead soft. Since hardening sets the maximum hardness, the blade maker has defaulted to what is required for the point. Now some of the hardness must be removed from the cutting edge (lest it remain too brittle) and especially the back / core (to allow flexibility).
Tempering is undertaken by carefully heating the blade in as controlled a fashion as possible. Changes in the component crystal structure will start to occur once the metal is heated to roughly 450 F. In practice, an extremely thin film of oxide starts to form on the polished metal, which can be seen as a progression of colours over the surface. The range from cool through to hottest is : Yellow / straw / brown / red / purple / blue / grey. At roughly 800 F the metal passes beyond the temper range and develops the solid grey iron oxide. Once the ideal combination of colours (thus temperatures) is observed, the blade is quickly quenched to 'freeze' the varied hardnesses in place. Depending on just what method is used to heat the blade when tempering, those temperature colours can develop extremely fast. If an error is made and the metal gets too hot, then the blade maker ** should repeat the entire heat treating process at the initial annealing phase **. One last surface polish remains to remove the thin oxide film before the blade goes on to be hilted.
Just what temperature / temper colour should be created just where on a given blade can vary considerably. Use of the blade, alloy selected, hardening degree, all will relate to the way the blade is finally tempered.
Most commercial knife makers will in fact avoid the skills involved and simply oven temper their blades. An average is determined, again based on the dynamics of the alloy and quenching. Then an electric kiln is set to a specific temper range and the entire blade is fixed at an average degree of hardness. Although use of more complex alloys can help give decent results, the simple truth is that an oven tempered blade will never perform as well a correctly eye tempered one.
(Note * correctly * !! Hand forging and eye tempering a blade requires a significant amount of acquired skills, knowledge and experience to create what can be a superior finished result. Its also easy to screw it up. All that accumulated practice comes with a cost. Machine ground and oven heat treated blades can expected to be uniform in quality and certainly much cheaper to produce.)
As I said when the topic of knives came up a while back - you get what you pay for...
Darrell
PS - I've intentionally left a lot of practical details out of this general description. Sorry, but I do earn a living from courses I teach on these subjects. I also recommend my DVD - "Historic Bladesmithing" - available on my web site.
Friday, March 09, 2007
Note to my Readers...
Sorry to those of you have came over here looking for new and good material. I'm in the middle of a real messy E-bay purchase right now and its sucking out what is left of my brain.
I will be working up some pieces in response to the comments and questions by Unnr and Bill earlier. I also will have a major announcement of a new publication being released on March 15.
Please stay tuned...
I will be working up some pieces in response to the comments and questions by Unnr and Bill earlier. I also will have a major announcement of a new publication being released on March 15.
Please stay tuned...
What's in a Name?
When the initial planning meeting for the Smithsonian's exhibit 'Vikings, North Atlantic Saga' was held, there was considerable discussion, both formally and over drinks in the evenings about the use of the terms 'Viking' and 'Norse'. The thirty or so at the sessions were gathered from the 'big names' in popular VA research, curators of major museums, cultural ministers from all the North Atlantic countries. Pretty high powered talent.
In the end the argument boiled down to this:
On one hand everyone recognized the responsibility we all had as educators to correct stereotypes. To use the correct term NORSE as defining a specific * material culture *.
On the other hand everyone clearly understood the painful truth that 'funding drives the event'. No funding, no exhibit. In the end it came down to simple 'product recognition'. 'Viking' brought in the ticket sales.
The subject resurfaced at the 2000 Viking Millennium Conference in Newfoundland. Curator of the exhibit Bill Fitzhugh did a presentation on the exhibit, and the subject of names came up in questions. That ended up a lot more heated - people actually yelling at each other.
The truth is that major institutions throughout Europe and North America will continue to use the incorrect term 'Viking' - because that is what the general public recognizes and responds to. Many museums make no apologies for this. Richard Hall of the Jorvik * Viking * Centre at York made a special point of featuring the use of advertising as the major reason for the success of that institution in his session at the conference. Good advertising yields large gate revenues, which in turn pay for the research. He made absolutely no apologies.
I certainly do my best to avoid the use of * Viking * as a single word description in all of my own presentation work. If you check over the documentation for World of the NORSE or the NORSE Encampment you will see this. I tend to use * Viking Age *, but that is a known definition used in academic circles. As an example of how my own work has been degraded by mere advertising: The presentation I created for L'Anse aux Meadows was always titled the 'Norse Encampment' in all my production notes and documentation. The agency who commissioned the project was called the 'Viking Trail Tourism Association'. So they (without informing me) changed the name on everything that was published. When Parks Canada assumed control of the presentation (thankfully!) several years latter, they retained the incorrect term in the name for continuity.
A bald truth to museum work - it is "The Art of the Possible".
In the end the argument boiled down to this:
On one hand everyone recognized the responsibility we all had as educators to correct stereotypes. To use the correct term NORSE as defining a specific * material culture *.
On the other hand everyone clearly understood the painful truth that 'funding drives the event'. No funding, no exhibit. In the end it came down to simple 'product recognition'. 'Viking' brought in the ticket sales.
The subject resurfaced at the 2000 Viking Millennium Conference in Newfoundland. Curator of the exhibit Bill Fitzhugh did a presentation on the exhibit, and the subject of names came up in questions. That ended up a lot more heated - people actually yelling at each other.
The truth is that major institutions throughout Europe and North America will continue to use the incorrect term 'Viking' - because that is what the general public recognizes and responds to. Many museums make no apologies for this. Richard Hall of the Jorvik * Viking * Centre at York made a special point of featuring the use of advertising as the major reason for the success of that institution in his session at the conference. Good advertising yields large gate revenues, which in turn pay for the research. He made absolutely no apologies.
I certainly do my best to avoid the use of * Viking * as a single word description in all of my own presentation work. If you check over the documentation for World of the NORSE or the NORSE Encampment you will see this. I tend to use * Viking Age *, but that is a known definition used in academic circles. As an example of how my own work has been degraded by mere advertising: The presentation I created for L'Anse aux Meadows was always titled the 'Norse Encampment' in all my production notes and documentation. The agency who commissioned the project was called the 'Viking Trail Tourism Association'. So they (without informing me) changed the name on everything that was published. When Parks Canada assumed control of the presentation (thankfully!) several years latter, they retained the incorrect term in the name for continuity.
A bald truth to museum work - it is "The Art of the Possible".
Monday, March 05, 2007
Historic Interpreter versus Re-enactor
You may have seen me use those terms in past postings. I make a clear distinction between the two.
Re-enactor - is what you are when you are at a closed event with just other re-enactors at it. Generally everyone you see will have some shared framework that is understood.
Historic Interpreter - is what you are when you work in front of the general public. Now there is a very good chance that you are interacting with people who DO NOT have any concept of the historical frame work at all.
The skills of a Historic Interpreter are quite different and much more demanding than that required inside a closed re-enactment. Quite frankly (as someone who trains Living History Interpreters), I find the approach to this fundamental aspect of public presentation sadly lacking in many highly visible * Re-enactment * groups.
For most re-enactors, the stress is placed on physical accuracy of equipment. (Often enforced by 'authenticity officers' who rarely understand the implications of the artifact samples selected.)
For the historic interpreter the stress is on communication method. What does the visitor's question really MEAN - as opposed to what on surface the question may appear. (That cabbage question was really about what kinds of foods were available in the Viking Age - and if ancient cabbage looked like modern supermarket cabbage. It could have been the lead in to a highly successful long conversation if handled correctly. This would have resulted in not only a better educated visitor - but one who would have ended up very pleased with their interactions in camp.)
One of the most effective physical presentations I ever saw used absolutely no actual object at all (in Dublin at the reconstruction based on Woods Quay as it turned out).
For those interested in improving their public presentation skills, I refer you to :
'Past into Present' by Stacy Roth
University of North Carolina Press, 1998
06-05-040302-7654
Re-enactor - is what you are when you are at a closed event with just other re-enactors at it. Generally everyone you see will have some shared framework that is understood.
Historic Interpreter - is what you are when you work in front of the general public. Now there is a very good chance that you are interacting with people who DO NOT have any concept of the historical frame work at all.
The skills of a Historic Interpreter are quite different and much more demanding than that required inside a closed re-enactment. Quite frankly (as someone who trains Living History Interpreters), I find the approach to this fundamental aspect of public presentation sadly lacking in many highly visible * Re-enactment * groups.
For most re-enactors, the stress is placed on physical accuracy of equipment. (Often enforced by 'authenticity officers' who rarely understand the implications of the artifact samples selected.)
For the historic interpreter the stress is on communication method. What does the visitor's question really MEAN - as opposed to what on surface the question may appear. (That cabbage question was really about what kinds of foods were available in the Viking Age - and if ancient cabbage looked like modern supermarket cabbage. It could have been the lead in to a highly successful long conversation if handled correctly. This would have resulted in not only a better educated visitor - but one who would have ended up very pleased with their interactions in camp.)
One of the most effective physical presentations I ever saw used absolutely no actual object at all (in Dublin at the reconstruction based on Woods Quay as it turned out).
For those interested in improving their public presentation skills, I refer you to :
'Past into Present' by Stacy Roth
University of North Carolina Press, 1998
06-05-040302-7654
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