Canola oil advantages

Tai Goo said:
As it pertains to a quenching medium for steel.

#1. Low price
#2. Great availability
#3. High flash point
#4. High smoke point
#5. No vapor jacket or vapor stage
#6. High speed at the onset of the quench
#7. Finishes slow
#8. High stability compared to other common vegetable oils
#9. Less sensitive to temperature variation than are the parrafinic oils
#10. Non toxic and relatively safe to use

Can you think of any others?

Quote:
“Overall, the cooling properties of the vegetable oils were comparable to each other and it is notable that only convective cooling was obtained with no extended vapor blanket cooling (film-boiling). This cooling profile shows that vegetable oils would not require a cooling rate accelerator and would be acceptable even for difficult to harden, crack-sensitive carbon steels.” VEGETABLE OIL QUENCHANTS: CALCULATION AND COMPARISON OF THE COOLING PROPERTIES OF A SERIES
OF VEGETABLE OILS
Click to expand...

Just to be fair, could you please play the devil's advocate let us know what the disadvantages of canola oil are.

I often find without discussing the negatives of a certain product or procedure, progress will never be made and stagnation occurs.
 
If you take a look at the article link I posted they discuss some of the limitations of Canola.
 
From what I gather from the information I've read, the main or only draw back for "industrial" high volume applications are the stability and oxidation problems. This can lead to added costs in large scale industrial applications.

For us humble knifemakers, it's just having to take care of it, and change it out occasionally.
 
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Canola can’t guarantee quench success, but neither can any of the other quenching mediums. So, I don’t count that against it.

I’d rather get back to the advantages, which we maybe could dig a little deeper into and there would be more to talk about.

I think “vapor jacket etc. vs. convection" might be a good place to start.

Anyone want to take a stab at it?

Quote:
"A brief historical overview of the use of vegetable oils as quenchants for steel has been provided. It was also shown that the quenching mechanism exhibited by vegetable oils is fundamentally different than that traditionally observed for petroleum-oil quenchants. While vegetable oils mediate cooling predominantly by convective heat transfer, petroleum oils exhibit an inherently non-uniform mechanism involving full-film boiling, nucleate boiling and convective cooling with often very different heat-transfer coefficients."
 
Here's my scientific anaysis:
I have used canola oil to quench about 1500-2000 leaf springs for knives-the same canola oil, BTW.
I have never had a spring returned to me, nor have I ever had one break in the 12 years I have been making them.
So-would a commercial quenchant have worked any better?
I also have used it for blades, and they worked great. Could they have been better? Maybe, but I still have no complaints.
 
Yes according to houghton's quenching doc:

"Stage 1. Vapor Phase

The first stage of cooling is characterized by the formation of a vapor film around the component. This is a period of relatively slow cooling which heat transfer occurs by radiation and conduction through the vapor blanket."




It's hard not to find it pretty obvious the quench mechanisms of veggie oils are drastically different with the apparent omission of vapor phase. It would also explain why they're considered to be initially very fast, yet slower afterward. The boiling phase of stage two is the fastest stage of heat transfer, which the vegie oils go into immediately, yet the convection stage is the slower phase, so perhaps canola has a shorter boiling phase and as such makes it less suitable for thicker cross-sectional geometry.

Anyway, that's speculation on my part, but it's definitely interesting.
 
Javand, The way I'm reading it is that there is no "boiling" phase with the vegetable oils. It's virtually all convection with a little smoking. Smoking being inherently different than boiling or “vaporizing“. Because there is no vapor jacket, there's no necessity for a cooling speed accelerator,... or agitation. Also, since with the vegetable oils we're only dealing with one mechanism of heat transfer as opposed to several, it extracts the heat more evenly and more uniformly which causes less stress to the steel and more uniform results.

In essence, the cooling mechanism for vegetable oils is less complicated and more direct.
 
Tai Goo said:
Canola can’t guarantee quench success, but neither can any of the other quenching mediums. So, I don’t count that against it.

I’d rather get back to the advantages, which we maybe could dig a little deeper into and there would be more to talk about.

I think “vapor jacket etc. vs. convection" might be a good place to start.

Anyone want to take a stab at it?

Quote:
"A brief historical overview of the use of vegetable oils as quenchants for steel has been provided. It was also shown that the quenching mechanism exhibited by vegetable oils is fundamentally different than that traditionally observed for petroleum-oil quenchants. While vegetable oils mediate cooling predominantly by convective heat transfer, petroleum oils exhibit an inherently non-uniform mechanism involving full-film boiling, nucleate boiling and convective cooling with often very different heat-transfer coefficients."
Click to expand...


Source?



What are the heat transfer coefficients of these fluids?
 
The sources have already been named and/or linked to in this thread.

The multiple quenching mechanisms and heat-transfer coefficients of the petroleum based oils are "non-uniform" and less efficient by nature.
 
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This discussion has proved to be a fascinating journey into how people reason, use their brains and make decisions. On a lighter note, I also enjoyed learning about Canola Oil substitutes in the unlikely event I am unable to procure Canola Oil someday.
 
Tai Goo said:
The sources have already been named and/or linked to in this thread.

The multiple quenching mechanisms and heat-transfer coefficients of the petroleum based oils are "non-uniform" and less efficient by nature.
Click to expand...

Wait. I thought we were talking about the advantages of canola oil as a quenchant and not the negatives of petroleum based quenchants.

Sorry, I'll not follow every link and source in this threads to back up your claims. My interest is academic: I used to do heat transfer and pressure vessel calcs for a living. There is a bit to consider, but for someone who is not afraid to do the math can look at the published data and tune the quenchant to the transformation temps and cooling curves of the steel. Hell, I bet someone has done that. No superationality required.;)


As well all know, one quenchant acts better with certain steels than others (air/ oil/ water...) O-1 in water is disaster, O-1 in oil "A" may be optimum, In oil "B" may not be optimum but generally good enough. For who its for.

Quote:
"A brief historical overview of the use of vegetable oils as quenchants for steel has been provided. It was also shown that the quenching mechanism exhibited by vegetable oils is fundamentally different than that traditionally observed for petroleum-oil quenchants. While vegetable oils mediate cooling predominantly by convective heat transfer, petroleum oils exhibit an inherently non-uniform mechanism involving full-film boiling, nucleate boiling and convective cooling with often very different heat-transfer coefficients."
Click to expand...

Blanket statements like this bother me, especially unsourced ones. ALL vegetable oils? ALL petroleum oils?
 
Tai Goo said:
Sorry, but in order to talk about the advantages of vegetable oils, there have to be a few things to compare it with.


For the third time in this thread:
http://www.industrialheating.com/Articles/Feature_Article/BNP_GUID_9-5-2006_A_10000000000001097301
Click to expand...

Interesting article. Raises more questions than it answers in my mind.

does anyone know how the two oils (microtemp 157 and 153b) referenced in the article compare to the more common parks 50 / AAA? A google search only finds the referenced article. . .

Of course the intro is most pertinent:

Properties of carbon and alloy steels vary with their composition and microstructures, which are dependent on the heat treatment and quenching process used.


Typically, steel is heated to its austenitization temperature and then cooled sufficiently fast to avoid pearlite transformation and obtain maximum hardness and strength. The critical cooling rate is dependent on both the specific heat capacity and thermal conductivity of both the steel and the quenchant in addition to quench-bath temperature and agitation.
Click to expand...
 
Good question.

I don't know about the microtemp 157 and 153b, but they are they same two used in another study on vegetable oil quenchants I read.
 
I do not have any scientific additions to this thread. No coupons micrographed or Rc penetrator studies. I do use a conola/peanut oil mix to quench some of my knives. Normally knives like 1084, O1, 5160 and much of my Damascus that parks might be a little too fast for. I do have parks 50 and mcmaster fastquench. I use them for 1095 and w-2 primarily. I use a forge to do my HT in. It is not controlled mechanically but I can tune it easily to run at one temp all day long. I also have a salt pot but since I can control my forge so well I have migrated to the forge almost exclusively.

I just received an email from a good friend of mine. We were hunting partners many moons ago and he commented on one of my knives I had made way back when. His comment actually made me think more seriously about continuing my knife making. I decided to send him a knife as a gift after he told me he was going moose hunting. So I sent him this one

Copy2ofDSC_0295.jpg


1095 and 15n20 blade quenched in the canola/peanut oil mix (turkey fryer oil)

Here is his email

"Hey dude!

Got back from my hunt a week ago. Had a blast. Missed a moose with three shots. Call me, I'll give up the details. Basically, shot at a moose with a rifle I never fired before. Check out the photos at the link below. The knife you gave me stayed sharp for all three moose the group got while all the others that were used needed sharpening. Damn fine knife and once again I thank you. Number one comment was it was "almost too sharp". Enjoy the photos!"

This is what I call a successful heat treat. Yes there was more than just one knife used but all the others required sharpening. If one of my knives can perform to this level I am very happy. Real world testing, that is what I like to see.

Sorry for the long post.
 
Tai Goo said:
Good question.

I don't know about the microtemp 157 and 153b, but they are they same two used in another study on vegetable oil quenchants I read.
Click to expand...
so 157 ad 153b are just canola oil and not modified
is this not a thread about canola oil quench and not "engineered quenchants " be it veg. oil petro.
 
butcher_block said:
so 157 ad 153b are just canola oil and not modified
is this not a thread about canola oil quench and not "engineered quenchants " be it veg. oil petro.
Click to expand...

I think(unless I misunderstood) that the Microtemp brand were the "medium" and "fast" engineered oils in the study, Butch. Someone asked if they were comparable to Parks 50 and AAA but it was not known.

Rick
 
butcher_block said:
so 157 ad 153b are just canola oil and not modified
is this not a thread about canola oil quench and not "engineered quenchants " be it veg. oil petro.
Click to expand...
No, the two listed quenchants are engineered petro-chemicals that were used to compare/contrast with the vegetable oil. Did you read the article?
 
Only 3 Moose? ;)

Thats awesome.

Maybe that is why it is called "CANola" and not "CANTola":D
 
Can't take full credit since 3 guys were working together. But it outperformed all the other knives in camp. In fact the kid that was using it had dulled his so bad he had a hard time getting used to mine. Too Sharp!! Love it.
 
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