Sunday, March 20, 2016

2 X short bits

Readers : You may have noticed a big gap in recent postings.
Life, the Universe, everything...

I * did * get that Ontario Arts Council Project Grant (!!!!)
This will put me in Belgium for the Ypres 16 event for the first week in September (see recent posts). Followed by four weeks at the Scottish Sculpture Workshop in Lumsden. First part is a continuation of the original Turf to Tools project, the second part my own investigations of the Scottish landscape through bronze and iron casting (and learning the techniques and equipment involved). Obviously much more on that to come.

The other things brewing here are seemingly endless work on travel arrangements, upcoming demonstrations / presentations and exhibit preparations. Again, expect to see some posts regarding those soon.

Here are a couple of short pieces pulled from recent e-mailed 'questions and answers'.*
Both relate to metal types, applications - and misconceptions :

Jeff wrote:
Hey, can you use wrought iron for a "flint and steel" or does it REALLY need steel? I would think any old iron bar would do, since the spark is going to spring from the oxidization of the iron.
A properly functioning 'steel' has to have both a higher carbon content - and just the right degree of hardness put into the metal after the finished forging.
What happens when you strike is that the flint tears out a small fragment of the metal.
The resistance to the tearing process is what accelerates the temperature, and the spark temperature and size is related to the hardness required to force the splinter off the surface. This in turn effectively pushes up the temperature of the splinter till it essentially burns - that is what the spark is (high temperature oxidation of the metal).

Too soft and the metal fragment does not get hot enough.
Too little carbon and there is not enough spark - or the resistance required to jump the temperature.

Honestly, This is one of those simple objects I have never had the best luck making - you have to establish and even process and the correct selection of metal to suit the best result.
Having good flint is also critical to consistent successful sparking as well. The black English is the best.

Like a lot of seemingly simple things, there is a lot of complexity behind this...


Alan wrote:
If I take a ball peen hammer and make a cross peen‎ or straight. Would I have to do a heat treat on it after I'm done my hamming?
Ideally - YES

Do remember that the base metal alloy in a hammer head should be higher carbon content than the mild steel you would be forging. These even despite that the metal being struck at forging temperature is significantly softer than any cold metal at the same alloy content.
Between these it tells you that you likely get away with just air cooling the re-forged hammer head, and using it in that state. You would eventually get some distortion / mushrooming of the striking surfaces.
But remember ancient hammers were just iron (not able to be hardened at all). These do show significant swelling at the striking faces - but did not effect the use of the tool.
Replica Norse blacksmith's tools (based on Mastermyr). Note swelling on the hammer face.
So the ideal is to harden and draw the temper back on your completed hammer head. This would produce the most durable tool.
Just how to best undertake this would depend entirely on the source alloy in the hammer head. Which is most likely completely unknown - right?

You might be better to leave your head a bit soft, and expect it to wear a bit faster. Getting the head *too* hard may lead to it cracking / even shattering  - at least potentially
Oil harden if you are going to attempt to harden at all would be my advise. Hammer heads I believe are tempered to a blue (but you should check that!)

* Readers Please Note : If you e-mail me and I follow up with a detailed response, I will often use those as the core of future blog postings. I will just use your first name and remove any other identity.

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

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