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I Forge Iron

Tempering steel with mercury?


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Over the past few weekends, I've been "apprenticing" under a local woodsmith/blacksmith who has been gradually introducing me to the many facets of this trade. One book he gave me to read is one I'm sure you're familiar with; Practical Blacksmithing, cataloged by M.T. Richardson. 

 

In chapter IV, Steel and its Uses, there is an article name "To Temper Steel Very Hard." It goes on to say:

 

"the most effective liquid is the only liquid metal-mercury. This being a good conductor of heat, in fact the very best liquid conductor, and the only cold one, appears to be the best on for hardening steel-cutting tools. The best steel, when forged into shape and hardened in mercury, will cut almost anything. We have seen articles made from ordinary steel, which have been hardened and tempered to a deep straw color, turned with comparative ease with cutting tools from good tool steel hardened in mercury." 

 

This seems so archaic to me, but in fact may be so for good reasons. I'm sure the dangers of mercury were known then, but they still took the good with the bad. 

 

I was just wondering if anyone has had the opportunity to try this method, or work with steel that has been tempered in this fashion.

 

He finishes with a bit of a disclaimer: "Beware of inhaling the vapor while hardening." 

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Read up on Robb Gunter's creation/formulation of SuperQuench to replace lye quench. There were lots of really, REALLY bad things in the shop before OSHA and EPA came into being. Its a wonder anybody made it to 50, much less 65.

 

Of course, its getting hard to find whale oil and baby seal fat in the lower 48, too. :wacko: Much less the DDT to get rid of the 'skeeters in the slack tub.

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I am 57 when I was a kid we used to play with mercury with our bare hands then eat grandmothers fried chicken with our unwashed hands. But then maybe that is why I am the way I am. they also used cyanide for case hardening into the 70s or later.

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MSDA Sheet for Mercury

 

 

 

Special Remarks on Chronic Effects on Humans:
May affect genetic material. May cause cancer based on animal data. Passes through the placental barrier in animal. May
cause adverse reproductive effects(paternal effects- spermatogenesis; effects on fertility - fetotoxicity, post-implantation
mortality), and birth defects.

 

Chronic Effects on Humans:
CARCINOGENIC EFFECTS: Classified A5 (Not suspected for human.) by ACGIH. 3 (Not classifiable for human.) by IARC.
May cause damage to the following organs: blood, kidneys, liver, brain, peripheral nervous system, central nervous system
(CNS).


Other Toxic Effects on Humans:
Very hazardous in case of skin contact (irritant), of ingestion, of inhalation. Hazardous in case of skin contact (corrosive,

 

Personal Protection:
Face shield. Full suit. Vapor respirator. Be sure to use an approved/certified respirator or equivalent. Gloves. Boots.


Personal Protection in Case of a Large Spill:
Splash goggles. Full suit. Vapor respirator. Boots. Gloves. A self contained breathing apparatus should be used to avoid
inhalation of the product. Suggested protective clothing might not be sufficient; consult a specialist BEFORE handling this
product.permeator).

 

For more real life exposure to mercury, look up the mining of gold, and making hats. The term *Mad as a hatter* was for a reason. I remember when someone dripped a glass, mercury filled thermometer, and broke it. They shut down the school and called in a hazmat crew to clean it up. They have mercury in the twisted electric light bulbs. Ever read what you are suppose to do when one is broken? 

 

Your call, but be safe.

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You may look into the first part of your quote.....about tempering to make steel very hard,,,,tempering actually is a way to reduce the hardness created by harderning a steel that will do that......It is cool to see wot the old ways were and think of how we have debeloped safer methods of shop work,,,,,I think!

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Actually "tempering" was the term used for the whole heat treat process back in olden times.  In more modern times we have broken it down into separate steps with differing names to help keep everything clear.

 

Note too that earlier low alloy steels were harder to harden and a lot of "custom snake oil" methods were recorded---"Sources for the History of the Science of Steel"  includes a collection of renaissance quenchants including such things as work water and radish juice.

 

If anyone has worked with antique engravers tools they may have used mercury quenched items; but the process definitely falls into the "expendable apprentice" bucket...

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I was just really surprised someone suggested that. It was only one article, and wasn't brought up again. Perhaps the smith had handled too much mercury for his own good, and it caused him to believe it true. 

 

I looked up the Super Quench formula; a lot of credentials. But what part does the dish soap play? 

 

Thanks, Thomas, that helped clear a bit up. 

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Detergent and Jet dry are surfacants, meaning they break surface tension so a liquid will contact the surface. That's how soap works, it's a surfacant so water can rinse the crud off your hide. for a quenchant it keeps steam bubbles from staying on the surface as Eric says above. thinking a bit, I believe it actually prevents from steam bubbles from forming, no surface tension, no bubbles.

 

If you're more into the commercial surfacants you can use "Sodium laural sulfate." It's what makes  we used in the soils lab to turn dirt to muddy water. It's reasonably non-toxic, not a transdermal and in fact is what makes most shampoos get your hair wet.

 

Frosty the Lucky.

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Lead and tin were also used for both quenching and tempering (both in heated liquid form as poking a hot tool into solid lead would be its own sideshow trick).

 

Porkchop,

As far as I know very few studies have looked into old methods of heat treating and the resulting microstructure. Many of the old ways have been supplanted simply by the use of modern steelmaking practices. The older made steels do not respond the same way that modern steels do and many of the alloys now used were not available for steelmaking in the past...well they had them around on Earth, but not in forms that were thrown into the pot.

An iron/carbon steel without alloys is hard to come by today and this was the mainstay for the old tools.

 

If you have the time have a read through the "Blacksmith's and Boilermaker's trade journals from the 1800's. They complain about the new manganese steel being sold as "normal" tool steel and how it is near impossible to forge or heat treat as it needed more force to forge and would crack if water quenched.

you see manganese rids steel of sulphur (binds it into MnS and renders it inert more or less rather than the Sulphur making the steel hot short)..it also increases the depth of hardness for the steel when quenched.

 

I would think the above MT Richardson quote relates to this type of steel.

 

Ric

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But isn't that the point of an agitated bath, and the addition of salt to reduce the oxidation? I'm sure the soap process to an extent minimizes the need for agitation. Ah, the ingenuity of the smith...trial and error, trial and error. Since I've been working at the foundry under the metallurgist and engineers, I'm certainly beginning to understand patience and technique (not to mention bizarre concepts to try as a last resort, almost always resulting in new, tried methods). 

 

Rich, thanks for the input. I hadn't thought much of the progress of alloys we've made in the past 150 years. I'm sure with carbon string applications being produced, the methods we think of will be archaic in 50 years. 

 

I guess the point is just to move on, and not stick with one idea. Those who don't evolve, perish with the wagon wheel. 

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  • 1 month later...

Read up on Robb Gunter's creation/formulation of SuperQuench to replace lye quench. There were lots of really, REALLY bad things in the shop before OSHA and EPA came into being. Its a wonder anybody made it to 50, much less 65.

 

Most didn't.

 

I once read the report of the UK surgeon general about working conditions in the Joseph Rodgers factories around 1850s. JR was one of the best and most prestigious brands in Sheffield. They were 'cutlers to their majesties' for a long while.

 

Anyway, it was as you said. Really bad working conditions. But the thing was that people themselves didn't care much, even though they knew it was bad. The surgeon general mentioned talking to a grinder who had spent all morning grading (true-ing) his new grinding wheel with a scraper. He was covered in thick grey dust from head to toe. Didn't even wear a handkerchief over his mouth. the doctor asked him why. He said that he knew he should, but didn't think to do it.

 

Joseph Rodgers was iirc the first workshop in sheffield to install an outlet fan in each building to blow grinding dust out. This was considered revolutionary. The factory came up with the idea to lower mortality rates. Up until then,, it all stayed inside, and the physcal location of each grinding station was such that the most senior and prestigious people (razor grinders) had the cleanest places, and each next less prestigious station sat in the debris stream of the previous one.

 

Fork grinders had the worst of the worst job, because they worked with very thin wheels, ejecting a lot of debris in a concentrated stream. The usual age for a fork grinder to die of lung failure was around age 27. No, this is not a typo. Twenty seven. No wonder people had kids when they were 14. If you wanted to raise them yourself, you had to start early to beat those odds. Compared to that, razor grinders had a very cushy job because they made it to 60.

 

File makers had it bad too. Lungs healthy as can be, but they usually ended up with all kinds of neurological degradation because of lead poisoning. Files were chiseled on a lead plate, and people didn't wash their hands before eating.

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 people didn't wash their hands before eating.

 

And when they did it was piped in  through a  lead pipe! After work they went down to the local to have a pint in a pewter(zink) tankard.

What a life.

 

Ian

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I read stuff like this with a mix of thoughts going.  First is an appreciation for how much better my lot in life is because of my fore-bearers.  The second is how it's a shame so many folks suffered needlessly.  I think about all the safety knowledge we take for granted then I remember the last time I was on a construction site I had to discipline an apprentice for not tying his shoes!

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Thanks heaps for this thread guys. I always find it interesting to find out the silly things we used to do in past industrial ventures. I myself have noticed a massive change in attitudes in the last 10 years alone! The "just get it done" hero is a dying breed. Mostly because they are now actually a dying breed. Which tends to limit any feedback that can be had on the practices of the day. Unfortunatly I have noticed the "cotton wool" approach causing its own problems in the youth of today. Regardless of work environment.

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Sad to say, but the "Git 'er done!" mentality is alive, if not well, here in the US of A. And it is not dying off before it breeds. Profusely.

 

Today I watched my next door neighbor, and his 15 year old son cutting grass and using a string trimmer. Shorts, barefoot or sandals, no eye protection. And he wonders why I don't want to teach him anything. These are the same folks who set up a BB and archery range in the back yard. Targets at chest level, with no backstop, less than 100' from the back door of the house on the next street over. "But there are bushes!" Yeah, right. All those stupid Asians and Europeans with their castles made of stone, when they could have just planted a shrubbery for defense.

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  • 5 months later...

I don't know Glenn... the flip side of all those "May..."... is surely "Might not".  :-)
Jumping in the water might drown you...
^_^ 

 

MSDA Sheet for Mercury

 

 

 

Special Remarks on Chronic Effects on Humans:
May affect genetic material. May cause cancer based on animal data. Passes through the placental barrier in animal. May
cause adverse reproductive effects(paternal effects- spermatogenesis; effects on fertility - fetotoxicity, post-implantation
mortality), and birth defects.

 

Chronic Effects on Humans:
CARCINOGENIC EFFECTS: Classified A5 (Not suspected for human.) by ACGIH. 3 (Not classifiable for human.) by IARC.
May cause damage to the following organs: blood, kidneys, liver, brain, peripheral nervous system, central nervous system
(CNS).

Other Toxic Effects on Humans:
Very hazardous in case of skin contact (irritant), of ingestion, of inhalation. Hazardous in case of skin contact (corrosive,

 

Personal Protection:
Face shield. Full suit. Vapor respirator. Be sure to use an approved/certified respirator or equivalent. Gloves. Boots.

Personal Protection in Case of a Large Spill:
Splash goggles. Full suit. Vapor respirator. Boots. Gloves. A self contained breathing apparatus should be used to avoid
inhalation of the product. Suggested protective clothing might not be sufficient; consult a specialist BEFORE handling this
product.permeator).

 

For more real life exposure to mercury, look up the mining of gold, and making hats. The term *Mad as a hatter* was for a reason. I remember when someone dripped a glass, mercury filled thermometer, and broke it. They shut down the school and called in a hazmat crew to clean it up. They have mercury in the twisted electric light bulbs. Ever read what you are suppose to do when one is broken? 

 

Your call, but be safe.

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