Using liquid soap as an agent in quenching?

F

ferroburak

Joined
Dec 18, 2010
Messages
8
Hi,
Has anyone tried using liquid soap as a secondary agent in quenching medium? It would delay the boiling of a liquid quenching medium I believe. Thanks.
 
What soaps do in any solution is lower the surface tension. There are soaps or some type of wetting agent in most commercial quenchants. By lowering the surface tension it increases the collapse of the bubbles that form along the hot blade. This increases the surface contact of the liqiuid...and speeds the quench. The ingredient in soap that makes all this happen is..........fatty acids, or oils.

When I was a research chemist at VirChem, I developed defoamers for industry. On one formulation, I used Burk's Reclaimed Motor Oil for the fatty acid, and KOH for the saponification agent. The end product could be delivered in tank trucks ,and worked fine for the paper industry...but would have been lousy for washing your hands and face with.

A lot of "GOOP" recipes have Dawn or some other liquid soap in it. If you are making a home brew quenchant, soap might help, but you would need to experiment a good bit to find the optimum amount to add.
With a commercial quenchant - it is probably already there in the proper amount.


For those who want to know these things:
The type of metalic ion used to make the soap will determine how solid the soap is. Lithium makes hard soap, sodium makes a somewhat plastic soap, and potassium makes the soap liquid.Mixing these and other metallic ions in the soap can get different results. Using a soft soap producing ion, like calcium, and a hard soap ion, like lithium will produce a high lubrication compound. This is the base of Lithium Grease.It works buy lowering the surface tension of the metals ( which it easily attaches to) and thus greatly increases lubricity.
Of course, There is a lot more to it than that, but soap is one of the oldest chemical compounds manufactured. In old times, the type of tree used to make the ash ( the alkalai source) would determine some of the hardness, and the type of fat/oil ( animal ,vegetable, mineral) would detremine the the pliability, mildness, and surfactant qualities. Not all oils will saponify,BTW.
 
Back in the day before I wised up and got actual proper quenching oil, I used 2qts of CVS mineral oil, 2 qts of Kerosene or lamp oil, 4.4 oz of jet dry for a wetter, and 4-6 oz of blue dawn dish soap for a surfactant. to me it worked splendidly, and skated files on W1 like no body's business. I never had any metalography done on it but it sure worked great in my book! but I didnt want to have to explain to my customer that I quenched there $100.00+ knife in a crazy, mystery quenchant. which could or could not be gaining full martensite transformation even if I do my part right... (see the point yet) leave the goops and buy real quenchant... it's $20.00 per gallon +/- :D. (Which is how much it cost me for my home made quenchant...)


Jason
 
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Thanks for that reply, Stacy, it cleared some things up for me.

A few drops of good old dishwashing liquid does help in the slack bucket (for cooling while grinding, not quenching during HT). By breaking the surface tension it lets the grindings and belt grit from your warm blade sink to the bottom so you don't get a scummy layer on top. Keeps your blade and belt cleaner.
 
Hi,
Would it be a good idea to mix water, oil and soap together to obtain a new quenchant(With oil being more dominant in the solution)? Thanks for the help.
 
james terrio said:
Thanks for that reply, Stacy, it cleared some things up for me.

A few drops of good old dishwashing liquid does help in the slack bucket (for cooling while grinding, not quenching during HT). By breaking the surface tension it lets the grindings and belt grit from your warm blade sink to the bottom so you don't get a scummy layer on top. Keeps your blade and belt cleaner.
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Good tip.

Thanks James
 
ferroburak said:
If you put soap they mix. (From bathroom experience if water is hot they even mix better.)
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Washing your hands is a far cry from quenching steel. I'll leave it to folks with more technical knowledge to explain why :) Please refer to bladsmth's post above.

Sean Cochran said:
Good tip.

Thanks James
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You're very welcome! I learned it from more experienced guys, just passing it on.
 
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Actually, Soap does not make water and oil mix. As a surfactant, it surrounds a small drop of fat/oil/grease and covers it , thus making the droplet, now called a micelle, to become suspended in the water. The oil then can be rinsed away. Dispersants are mixes of surfactants, which suspend and polymerize the oil....but does not make it mix, either.
 
bladsmth said:
Actually, Soap does not make water and oil mix. As a surfactant, it surrounds a small drop of fat/oil/grease and covers it , thus making the droplet, now called a micelle, to become suspended in the water. The oil then can be rinsed away. Dispersants are mixes of surfactants, which suspend and polymerize the oil....but does not make it mix, either.
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No chance of mixing oil with water?
 
"No chance of mixing oil with water?"
Not and have any good combined properties.

I have heard of chaps trying a quench tank with a foot of oil on top of a foot of water. They supposed that it would cool down in steps. The problem is the steps are backward.

The reason that oil and water don't mix is due to a lot of head numbing chemistry and physics, but short answer is that they just don't match up with each other.

During those old experiments I did, I was mainly trying to get the oil into a form that was soluble in water. At one point, we bought a surplus homogenizer from the dairy industry, and ran the oil/water/other chemicals through the machine. What that did was push the mixture through a small hole in the end of a sapphire nozzle. Up against the nozzle was a plate with a flat sapphire surface. This was forced against the nozzle with a huge screw shaft, creating extreme pressure as the liquid passed through in a one molecule thick film. The oil and water would get so completely mixed together that they would not separate when the liquid came out of the discharge tube. This mixture was water soluble to some degree, but lost some of the properties of water and of oil. It also came out very slowly, and that was not going to work for making tens of thousands of gallons of the defoamer.

The quenching properties of water are adjusted by changing the density and boiling point...or by polymerizing it. Adding alcohol lowers the freezing point, adding salt raises it.
The new commercial water based quenchants are polymer compounds. I haven't used them, but plan to experiment next year and see how they work with the knife quenching process. Just because it is great for cooling down car axles doesn't mean it will work for 4 ounce fillet blades.

Oil is easier to adjust, as more there are many types of oil. By mixing oils of different properties, along with wetting agents and surfactants , the manufacturer can blend up a quenchant that does a specific task optimally....and with repeatability.

Even if you made up a working home brew of water, soap, and oil....every time you quenched, the properties would change due to chemical reaction and water loss.
 
You can mix oil and water in space IIRC? LOL

I add some plain old dish soap so my very salty very cold brine for quenching hammer heads, It didn't hurt, and this decision to do so was brought on by the Superquench thought up by Robb Gunter.
 
Sam,
You are always good to add some sort of wetting agent to water quenchants for low carbon steel. A little Dawn wouldn't hurt a brine quench. It is cheaper than Jet-Dry,too.

If one wishes to make a home brew quenchant, the recipes for GOOP and Superquench are good places to start. These blends have been tweaked for a long time, and will work. The variability makes them not the choice for many of us, but the results will surely attain a usable hardness.
 
There is a set recipe for Superquench as told by Robb Gunter, I wouldn't count in with the goop and glop.
 
bladsmth said:
"No chance of mixing oil with water?"
Not and have any good combined properties.

I have heard of chaps trying a quench tank with a foot of oil on top of a foot of water. They supposed that it would cool down in steps. The problem is the steps are backward.

The reason that oil and water don't mix is due to a lot of head numbing chemistry and physics, but short answer is that they just don't match up with each other.

During those old experiments I did, I was mainly trying to get the oil into a form that was soluble in water. At one point, we bought a surplus homogenizer from the dairy industry, and ran the oil/water/other chemicals through the machine. What that did was push the mixture through a small hole in the end of a sapphire nozzle. Up against the nozzle was a plate with a flat sapphire surface. This was forced against the nozzle with a huge screw shaft, creating extreme pressure as the liquid passed through in a one molecule thick film. The oil and water would get so completely mixed together that they would not separate when the liquid came out of the discharge tube. This mixture was water soluble to some degree, but lost some of the properties of water and of oil. It also came out very slowly, and that was not going to work for making tens of thousands of gallons of the defoamer.

The quenching properties of water are adjusted by changing the density and boiling point...or by polymerizing it. Adding alcohol lowers the freezing point, adding salt raises it.
The new commercial water based quenchants are polymer compounds. I haven't used them, but plan to experiment next year and see how they work with the knife quenching process. Just because it is great for cooling down car axles doesn't mean it will work for 4 ounce fillet blades.

Oil is easier to adjust, as more there are many types of oil. By mixing oils of different properties, along with wetting agents and surfactants , the manufacturer can blend up a quenchant that does a specific task optimally....and with repeatability.

Even if you made up a working home brew of water, soap, and oil....every time you quenched, the properties would change due to chemical reaction and water loss.
Click to expand...

Thanks for the all info. I think there is no practical way of making a %70-x oil %30 water mixture then.
 
This thread is interesting has any one tried parks enviroquench? I am getting ready to do my own heat treating and start forging. Would this be a good quench medium for indoors?
 
That is one of the water soluble quenchants I was going to try. Somewhere on the note board, I have the name of the tech guy at Heatbath to talk to about using this for knives.

Since you are interested, Why don't you give Parks/Heatbath a call and talk to a rep about this quenchant. Try and have him email you the cooling rate charts, and any other data they have. Ask about quenching thin section hyper-eutectoid steels. The final question will be the packing quantity and minimum purchase. Might be something that several makers in an area ( or chaps like Aldo) can make a bulk purchase on and split up.

Post the data on a new thread and we can all discuss it.
 
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