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Art of Salesmanship: Heat treatment test using good ole Horseshoe

The horseshoe thing was a great piece of salesmanship. I imagine the horseshoe had been annealed better than the axes were heat treated.

I was surprised how shallow the heat treat was. I can see how that would give that style of axes a bad name. It wouldn't take much grinding to get past what was hardened.

I have seen something similar in one of Cambodian Blacksmith videos. I believe it is only shallow quench, pause, dunk and it is not followed by tempering. I wish I could understand what they are looking for when they stop quenching and what determines the time between quench and dunk.
www.youtube.com/watch?v=Ms7QmSQvMdk&feature=youtu.be&t=470
 
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Coincidentally I am working at the moment - even now even with an axe kept at hand for use from time to time - with this wood they are busy sawing in the film. Only worth a mention because it is a tree not commonly harvested other than for pulp or match making, Populus alba. (The image shows not only the axe but the wood in use as well.)
 
I believe it is only shallow quench, pause, dunk and it is not followed by tempering. I wish I could understand what they are looking for when they stop quenching and what determines the time between quench and dunk.

Well...(if i may interject my $.02)..."Shallow quench",do you mean in Length of bit HT'd(like what i think Square_peg means above)?
That,i believe has to do with this being a remnant,a tail-end of a vital,living axe-culture.
Where the guy using that tool had an easy access to the smith;as the tool wore down it was more than just the L of the bit-it was the whole geometry of it.Then you just went back and had it drawn back out to shape,and re-HT'd while at it.So that there was no need to have too long of the bit HT'd.

As far as Quench/pause/dunk:The Quench is the first dunk(it happens Fast,a few seconds at most*).
After that the Pause allows the smith to watch the heat penetrate back to the now-quenched edge from the thicker parts back that still retain Lots of heat.
He's watching for the correct Oxidation color to reach the edge(or,since he didn't give it a quick scrub with anything(colors are visible best on shined-up metal),he may just be going by time which he keeps track of by habit,by rote).
Once the correct color reaches the edge,i.e. the edge was Reheated to an Nth temperature(which Is Tempering),smith then terminates the entire process by dunking the whole enchilada.

Such tempering cycle is called "blacksmith's",or "self-tempering",when using the residual heat from the quench.

* "Shallow" can be a confusing term to use in such matters:There's a metallurgical meaning of this term as it applies to different alloys,"shallow-",vs "through-hardening".
"Plain-carbon" alloys(with Carbon the only alloying element) are considered "shallow-hardening"
That means that after a certain Thickness(i believe the standard is held to be 1/2"),the quench will not form Martensite(or other desired state)inside the forging,it'll loose it's T before the cooling can take it's place,and will form a different structure.

To fix that,to through-harden thicker forgings alloying elements are used,most notably Chromium.Cr carbides somehow facilitate and speed-up the process making the alloy "through-hardening".

I hope that's not too obscure...And thanks a LOT for these videos!I got lucky with my reception over the weekend and watched a bunch of those,WAY cool!!!:)....
 
P.S.

I think the horseshoe "trick" is real;i doubt Very much that horseshoes Anywhere(until recent times)were made out any alloy that was hardenable...They were certainly not Hardened,apurpose!:)
Just dumb iron is very soft indeed,even today's "mild" steel,it'd be a fair medium to test whether the edge was left too hard(it'd chip),or overly soft(it'd fold over),and can Very easily form a sort of local standard,based on known qualities of both their average horseshoes as well as their local requirements for edge hardness for their woodworking tooling.
 
P.P.S.

Such tempering cycle is called "blacksmith's",or "self-tempering",when using the residual heat from the quench.

I forgot that i've just had to do that,to self-temper this bit on an ice-chisel.
Here it is,the surface of steel bit shined up quickly right after the quench,and there are the colors running up it from direction of the un-quenched mass at base of bit:

15.jpg
 
Well...(if i may interject my $.02)..."Shallow quench",do you mean in Length of bit HT'd(like what i think Square_peg means above)?
That,i believe has to do with this being a remnant,a tail-end of a vital,living axe-culture.
Where the guy using that tool had an easy access to the smith;as the tool wore down it was more than just the L of the bit-it was the whole geometry of it.Then you just went back and had it drawn back out to shape,and re-HT'd while at it.So that there was no need to have too long of the bit HT'd.

As far as Quench/pause/dunk:The Quench is the first dunk(it happens Fast,a few seconds at most*).
After that the Pause allows the smith to watch the heat penetrate back to the now-quenched edge from the thicker parts back that still retain Lots of heat.
He's watching for the correct Oxidation color to reach the edge(or,since he didn't give it a quick scrub with anything(colors are visible best on shined-up metal),he may just be going by time which he keeps track of by habit,by rote).
Once the correct color reaches the edge,i.e. the edge was Reheated to an Nth temperature(which Is Tempering),smith then terminates the entire process by dunking the whole enchilada.

Such tempering cycle is called "blacksmith's",or "self-tempering",when using the residual heat from the quench.

* "Shallow" can be a confusing term to use in such matters:There's a metallurgical meaning of this term as it applies to different alloys,"shallow-",vs "through-hardening".
"Plain-carbon" alloys(with Carbon the only alloying element) are considered "shallow-hardening"
That means that after a certain Thickness(i believe the standard is held to be 1/2"),the quench will not form Martensite(or other desired state)inside the forging,it'll loose it's T before the cooling can take it's place,and will form a different structure.

To fix that,to through-harden thicker forgings alloying elements are used,most notably Chromium.Cr carbides somehow facilitate and speed-up the process making the alloy "through-hardening".

I hope that's not too obscure...And thanks a LOT for these videos!I got lucky with my reception over the weekend and watched a bunch of those,WAY cool!!!:)....
Jake, thank you for the explanation of the whole process.
Can you imagine any town without tire shop? The same goes for blacksmiths in any European city before automobile era. Than comes US and rapid expansion West. Not enough Blacksmiths to go around so got to manufacture horseshoes and axes in bulk, and make those axes last much longer.
Coincidentally I am working at the moment - even now even with an axe kept at hand for use from time to time - with this wood they are busy sawing in the film. Only worth a mention because it is a tree not commonly harvested other than for pulp or match making, Populus alba. (The image shows not only the axe but the wood in use as well.)
I am looking at that pic: Is that plywood made from that tree?
 
Jake, thank you for the explanation of the whole process.
Can you imagine any town without tire shop? The same goes for blacksmiths in any European city before automobile era.
In my time living in Friesland I have watched as two villages have lost the last of their blacksmiths, never to return. These were places you went to get actual work done, first and foremost the farmer getting his horses shod, (horses maintained for daily work up to the 1970's in the case of the farm I'm living at), and in my time that could mean a bit of convincing getting the old smid to fire up the forge because the workload was low, the shop serving more as a gathering place for local misfits . Still he did a kind of work no contemporary smid, if you can find one, can do. (Jake would be the closest you'd come). The last one, here in my village, got into a conflict with the neighboring farmers when the farmer's son, against his father's advise, abandoned the smid for the machinists shop in the town. So it was with the decline.
Than comes US and rapid expansion West. Not enough Blacksmiths to go around so got to manufacture horseshoes and axes in bulk, and make those axes last much longer.
Yes, in a book I'm reading now about the settling of the Plateau Valley under that expansion implication gets made a time or two of this shortage of blacksmiths in that equation and I think it's the case that this trade never did get much established there except to the barest extent.
I am looking at that pic: Is that plywood made from that tree?
No, not at all the plywood is Baltic Birch it's the flooring which I'm working atop that is from Populus alba. Poplar wood is the ideal flooring for in the hayloft because of its particular wear resistance. Something else we would do well to remember.
 
that could mean a bit of convincing getting the old smid to fire up the forge because the workload was low, the shop serving more as a gathering place for local misfits .

Good Lord,Ernest,must you be so brutally direct?!

:)

Good for you for working with all that good poplar...It sure Is a tremendous wood,in a number of special applications.
I helped build a small sauna out of Balsam poplar timbers earlier this summer,and was Sure that i just recently took a photo of a finished job,but of course can't find it...:(
(it Did get done though and is being used with Great profit and enjoyment,which is the main thing anyway)
 
Good Lord,Ernest,must you be so brutally direct?!
As I understand it Jake your forge is also a social & welcoming place, But you know what they say all the time 'bout when you must strike?

While you look for your one example I'll post one up that's all about the good qualities of Poplar. In this simple cabinet I've used The Silver Poplar mostly and for the drawer fronts Black.
pa251093.jpg
 
That's some beautiful woodwork there Ernest,for sure.I always found poplar very attractive.

Just read up on assorted poplars in general,some very neat stuff.
Apparently it's particularly valued for...lots of different things...among which are those big,tall,solid-stump butcher blocks,for use with serious meat-axes.
(incidentally learned that charcoal produced from it has a certain % more C content than pine or birch,and when burned produces a commesurate % of calories more...I ought to try forging with cottonwood charcoal!:)
 
(incidentally learned that charcoal produced from it has a certain % more C content than pine or birch,and when burned produces a commesurate % of calories more...I ought to try forging with cottonwood charcoal!:)
Up until a certain point I'd assumed that poplar was too light for giving much heat, comparatively, but when I spent a winter heating with that wood found it wasn't so and now would take it for heating any time. It is so that burning it in the open hearth keeps you busy loading but in the boiler contraption I have one load's as good as anything, oak or otherwise. Still, it's been a while that I've burned it since I'd rather slab it, season it and make things with it.
 
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