The link yielded a pdf download for me.

I have some empirical observations to add to this erudite "fray", from grinding and quenching tungsten carbide every night.

Be a bit though, surprise guests from Tucson are arriving at my gate.......

Robert Taylor

28 minutes ago, SLAG said:

Lat.

The u.r.l. produced a blank page when I tried it. Has it worked for others?

SLAG.

It is a very large file, perhaps your carrier didn't allow the transfer.

Latt,

Thank you for the response.

Regards,

SLAG.

Check your files. When I get a PDF link I also get a blank page, but the file was downloaded.

51 Megabytes.

The question is not so much whether a difference exists but whether that difference is enough to justify any but the critical case.

For example, in this scholarly article by the US Department of Energy and done by the Lawrence Berkley labs, the thermal conductivity of Pure water to saturate salt is on roughly 3% at 100c.  https://www.osti.gov/scitech/servlets/purl/6269880  The graph on page 18 is probably the clearest way to view the data rather than the statistical charting.  Heat transfer goes down that 3% with more salt--I would have originally guessed the opposite due to the increased density.

Someone posted a data reference which seemed to contradict this study.

At 3% from saturated to salt free, the nature of the "swish" has a much greater affect than the salt in the water from a purely heat transfer standpoint.  Dip the part with slightly (even unintentionally) more agitation and you have a far greater effect than the salt itself.

So...it seems to come down to the slight difference in boiling point.  The reference I found yesterday appears to have been wrong---the boiling point is actually 108.7 c. not the 102 c which I found in one reference.  For that I apologize. That's a much bigger difference---227 f for those still thinking in the imperial scale.  That's clearly enough to be considered significant in reducing the thermal blanket of steam.  

The question is still whether the hassles of a corrosive bath in a bucket are worth the effort--There are lots of sloppy tolerances (such as guessing the temp by color) to the average amateur shop doing heat treating which probably still supersede the benefits of salt.  I think I'm still in the corral that salt/no salt is a simple preference rather than a specific benefit unless you are doing tight tolerance heat treating and watching all the other factors closely and consistently.

 

 

 I see now that my little statement earlier from the monograph was a blanket statement. It has already been said that there are lots of variables. My source further stated that the water or brine temperature should be well below 60F; no more specifics on temperature. The amount of salt suggested to add to the water for the brine was 5% to 10%. Whether by volume or weight was not mentioned. Agitation and vapor blankets were mentioned, but in another paragraph, and it was a rather general statement about the vapor being a significant barrier to heat abstraction. The same source said that the brine had the ability to "throw" scale off the quenched piece.

I was able to spend six days with the premiere saw maker of Japan (Yataiki) R.I.P.,  when he gave a workshop in Iowa in the 1990's. On his small tools, he would apply a coating of Miso paste before hardening. He didn't explain, but we knew that the paste was salty.

 

But what about "add salt till it will float an egg"????

Actually the miso paste sounds more like the salt and flour pastes used to protect files from decarburization when they are heat treated in traditional western practice.

Mmmm...miso....

does anyone bother using brine these days?

Of course I brine before I smoke. Use less sugar for bacon than fish but a little Tobasco is always appropriate.

After all these years now I don't know what to use or why! 

Frosty The Lucky.

36 minutes ago, Frosty said:

Of course I brine before I smoke. Use less sugar for bacon than fish but a little Tobasco is always appropriate.

After all these years now I don't know what to use or why! 

Frosty The Lucky.

The chemistry of brining meat is actually pretty fascinating: the salt in the brine pulls some of the moisture out of the cells of the muscle tissue, but once that moisture is in equilibrium, the osmotic process enables the dissolved flavorings to pass through the cell walls and season the meat from the inside out.

On February 22, 2017 at 6:12 PM, SReynolds said:

 Apparently the published experts don't agree.

Therein lies the problem.  Either you don't understand that publishing does not necessarily equal total expertise (thou it often does) or you do understand and are trying to troll folks into beating up on books for beginners.  And when you get really deep into a field of study "publishing" just means that you are defending a hypothesis with empirical data and are asking for peer review.  

The authors of and target audience for "popular" smithing books, as well as the technical editors for same, don't really have time or inclination to explain how solution x at y temp with z agitation will harden a,b,or c alloy.  They are just letting you know that there are a LOT of variables and you should go do your own research.  Which many of the other posts in this thread show folks here have done admirably.  Do your research, check your sources, and check your sources' sources.  

 

20 hours ago, Alan Evans said:

It is all fraught with danger though...people that write reference books are not always practicing or practical people. They make mistakes. I even know of two well respected practitioners in this field that have made mistakes when it came to putting their knowledge in print.

I agree though it is the best we have got.

Alan

True, but starting with a textbook as opposed to getting your information from an unqualified source, will give you a much stronger learning base and curve.  

I do not know if I missed it but nobody mentioned the thermal capacity of the quench. Water has very high capacity. Clean water is 1 in Imperial measures (definition of BTU). Sea water is 0.93 and olive oil is 0,47. If we disregard Mr Leidenfrost for a moment; heat transfer from a solid body in a fluid takes place in a thin laminary layer. Outside that layer we can forget about the transfer. Outside, the movement of the fluid is turbulent meaning that heat transfer is so much higher. The thickness of the laminary layer can be calculated but that would be rather meaningless since the influencing parameters vary so much in a blacksmith shop situation and are unknown. One thing is clear though. The viscosity of the fluid is important. Any movement of the solid is also important. I should believe that the viscosity difference between oil and water is the most important difference between the two - and is dependent upon oli temperature. Termal conductivity the second, Thermal capacity the third. Agitation is obviously very important.

We can get a stable jacket of steam if we dip a red hot piece in water and that jacket is probably as important as the laminary layer. Compare the difficulties in heat treating anvils. If the salt can do something to that layer it might well be important. However I assume that there are very little data available. Most research was done on boilers and they are neither running on brine nor heated so high that Leidenfrost layers form. Someone with a gas forge could easily experiment. Heat two pieces at the same time to the same temperature, dip them in water resp brine for a controlled time and measure the rest temperature after they have equilibriated. You would not need a very sofisticated setup. I cannot do it myself - I have no gas forge.

Thickness of the piece is also important A thick piece has not only more heat. The distance for the heat to get to the surface is also longer.

Common salt is not alkalline by the way. 

4 hours ago, Gerald Boggs said:

True, but starting with a textbook as opposed to getting your information from an unqualified source, will give you a much stronger learning base and curve.  

Who qualifies the qualifier? I suppose reference books should be more sought after and/or trusted in their second or third editions, when any errors have been corrected. Unlike literary tomes which attract a first edition premium.

Alan

Now you're just splitting hairs.

50 minutes ago, Gerald Boggs said:

Now you're just splitting hairs.

No, just trying to make the same point. Healthy scepticism. We should not blindly accept something simply because it appears in print, however worthy the tome. 

From a position of ignorance how do we know what sources are correct? If the writers of the reference or textbook consulted the wrong practitioner or incorrectly recorded the researchers' or practitioners' experience, how can we know?

Philosophically we know that in "physics" a model is constructed which fits the observed phenomena and that is taken as the hypothesis until evidence is found to the contrary, when a new model which takes account of the new evidence is devised to replace the previous one.

All we can do is keep an open mind and build our individual world view from the information we acquire, and subsequently accept or reject.

This thread is a case in point....if you follow the various bits of quenching and quenchant information arriving in sequence it is only after a fair bit of conjecture that a consensus was formed. If you stopped reading early on although the information was not incorrect it was certainly incomplete.

Alan

Theories should predict new experiments, as predicted by that theory. And those experiments should work out. If they do not then it's good by for that theory,

And published results should be reproducible, by other scientists or technologists.

Regards,

SLAG.

1 hour ago, SLAG said:

Theories should predict new experiments, as predicted by that theory. And those experiments should work out. If they do not then it's good by for that theory,

And published results should be reproducible, by other scientists or technologists.

Regards,

SLAG.

What he said...or...that's easy for you to say!  

That is a far more eloquent version of what I was trying to say in my "middle eight".

Thank you.

Alan

6 hours ago, Alan Evans said:

No, just trying to make the same point. Healthy scepticism. We should not blindly accept something simply because it appears in print, however worthy the tome. 

From a position of ignorance how do we know what sources are correct? If the writers of the reference or textbook consulted the wrong practitioner or incorrectly recorded the researchers' or practitioners' experience, how can we know?

Philosophically we know that in "physics" a model is constructed which fits the observed phenomena and that is taken as the hypothesis until evidence is found to the contrary, when a new model which takes account of the new evidence is devised to replace the previous one.

All we can do is keep an open mind and build our individual world view from the information we acquire, and subsequently accept or reject.

This thread is a case in point....if you follow the various bits of quenching and quenchant information arriving in sequence it is only after a fair bit of conjecture that a consensus was formed. If you stopped reading early on although the information was not incorrect it was certainly incomplete.

Alan

All I wrote, was that a textbook was a better source for information then an unqualified source.  I have no idea as to what you trying to say and frankly I don't care. 

Edited

Sorry to hear that. And a bit surprised. I thought we were just discussing the OP's theme of how do you know which book is correct.

Maybe you missed the bit where I said I agree with you that it is the best we have got.

 

Alan

All interesting reading. Especially "check the source of the source"

How you do proper research is often not covered well in school and the number of examples of generally good books with small bits of bogus information hiding in them is enormous, Shoot even Theophilus has that bit about carving rock crystal in "Divers Arts"

I found "The Sword in Anglo-Saxon England" interesting as it explored how to research an area where not a lot of direct information was known at the time and so a lot of indirect sources had to be used.

22 hours ago, Alan Evans said:

Sorry to hear that. And a bit surprised. I thought we were just discussing the OP's theme of how do you know which book is correct.

Maybe you missed the bit where I said I agree with you that it is the best we have got.

 

Alan

You're right and I apologize, that was completely out of bounds.  My mother recently died and I find myself a bit short tempered this days.  I though you were trolling and lashed out.  Again, my apologizes