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Kevin R. Cashen
09-23-2010, 12:32 PM
Although I am very careful to protect the privacy of my clients for whom I do consulting and testing, this research has so much educational value that I asked for permission to share some of the results with my knifemaking friends. I am currently involved in a project to help a quenchant manufacturer (not Parks or Houghton) develop some oils to specifically meet the demands of certain steels. The first goal is a very fast oil that will work for shallow hardening steels, so I am testing with a fast oil control.

Below you will see results from one of the first prototype formulations, starting at lower speeds, on 1095. 1095 is one of the toughest to thoroughly harden so I thought it would be a good challenge. The samples where ground from the same bar of steel, austenitized side by side with direct thermocouple monitoring in salts, and quenched side by side in identical quantities of oils and agitation, surrounded by a 125F bath to assure temperature. The results were then cross sectioned and roughly polished for metallographic examination (so please overlook the scratches). Micrographs were actually taken at 1mm increments from the edge but I only took a sampling to put this image on the web. After this the samples were then tested for Rockwell hardness at roughly 3mm increments.

http://www.cashenblades.com/forum/oiltest.jpg

The light background is martensite (the good hard stuff we want), the dark stuff, making it look like blue cheese, is fine pearlite (the soft stuff that quenching is supposed to avoid). Please be aware that at the edge both of these samples would have skated a file just fine, would have flexed over a brass rod all you want, and would even have cut a few 2x4” with little problem. But every little black patch represents a percentage of overall loss in strength, and long term edge retention.

Do be aware that that prototype oil would probably have held its own against many medium speed oils and was made by guys who’s business it is to make oils specifically for quenching and know what they are doing. This was a good oil but was still a first step in moving from medium to the fast speed, with a few adjustments that were yet needed to reach the goal, and many more tests in that process. But the speed factor is just one area among many to account for, long term stability, vapor points, interaction with the surface finish etc…

The real point of this post is that making a real quench oil isn’t all that simple and testing it is even less so, believe it or not these are just rough preliminary tests and not all that exhaustive. I hope this gives somewhat of an insight as to my perspective when I express my doubts about some of the homemade and improvised quenchants some folks feel work “just fine”, and I hope it gives food for thought to those who feel carefully considered quenchants are unnecessary.

Dwane Oliver
09-23-2010, 03:57 PM
Thats pretty interesting. I'm a newb at this
Question : What is the best "fast" oil currently on the market for 1095 ?

EdCaffreyMS
09-23-2010, 04:14 PM
Kevin,

You've got my full attention.....so spill your guts, I know more folks than just me want to know what your "control" quenchant is. :) I do have to ask the question, was there a specific reason that 1095 was chosen as the test steel?

I'll keep watching! Many thanks for taking the time to share!

Carey Quinn
09-23-2010, 04:38 PM
That has got to be the best explanation for using the proper quenchant I have ever seen or heard.

Thanks for sharing,
Carey

son of liberty
09-23-2010, 04:47 PM
Ya what is the Control Quenchant?

Leatherface
09-23-2010, 05:27 PM
Almost has to be parks 50

has to be

great post Kevin!

Kevin R. Cashen
09-23-2010, 07:21 PM
In time I will be able to reveal much more, but in the meantime the information and results are really not mine to give. I chose 1095 because it is the toughest to fully harden steel commonly used by knifemakers, nail a good curve with that steel and any shallow hardening alloy should fall into line quite well. Just remember that while Parks #50 is indeed a very good fast quench oil, it is not at all the only one out there. I would love to be able to do all sorts of these types of tests but I would also love to make all kinds of blades just for me to have for myself, and for the same reasons I cannot do either. But when you are doing it for a client suddenly the time is not just time loss to the business end of things. But the specifics of what I am trying to do with this client is separate from the striking lesson of how much a difference very small changes in the quenchant can make. Knifemakers will use many substances that had no quenching considerations in their creation, and be quite content with the results, for some time I have been painfully aware of what even the subtle differences in carefully formulated quenchants can make, my hopes were to give a little insight into why I am such a neurotic bug about it.:3:

Kevin R. Cashen
09-23-2010, 07:31 PM
Thats pretty interesting. I'm a newb at this
Question : What is the best "fast" oil currently on the market for 1095 ?

Any oil with a rating faster than 9 seconds should get you in the ballpark. Many would recommend Park Metallurgical #50, which is indeed fast enough but is also very hard to obtain or even more expensive. I would recommend a few of the oils offered by Houghton International, like type "K" or Houghto-Quench 3440 which may be about the fastest out there. Parks #50 has become all the rage, and I share a large part of the guilt for that, but Houghton is the largest, oldest and more friendly to deal with, so I cannot recommend their products enough.

Leatherface
09-24-2010, 04:32 AM
Kevin,
Just forgiggles and cause your da man


what is the recommended quench temp for oils like houghton and parks 50??

Kevin R. Cashen
09-24-2010, 07:09 AM
Most oils work best in a range from 100F to 150F, above that is bad. Some very fast oils such as the #50 can work from room temp on up to 130F but should not be allowed to go hotter. I do not have the exact numbers for the Houghton stuff right in front of me but the range is still valid. The medium speed oils are not as touchy, they have higher vapor points and so can handle the higher end of the same range.

Dwane Oliver
09-24-2010, 08:01 AM
Thanks Kevin.
Houghtons website says min temp of 70f to a max of 200f , with a recommended temp of 140 - 160f

Holly Hell , $250 for 5 gal.............I guess it would last quite a while though.

Seth Howard
09-24-2010, 01:47 PM
Holly Hell , $250 for 5 gal.............I guess it would last quite a while though.

Recently I contacted a Houghton dealer about a Med speed oil and the quoted price was actually half that.


Seth

son of liberty
09-24-2010, 08:37 PM
Parks #50 I saw on another sight as a group buy for 100 for 5 gallons.

Dwane Oliver
09-24-2010, 09:24 PM
Parks #50 I saw on another sight as a group buy for 100 for 5 gallons.

I could handle that , Where ?

Leatherface
09-25-2010, 01:45 PM
Parks 50 for 100.00 sounds like a winner to me as well...

Mark Behnke
09-25-2010, 03:56 PM
As of April of this year Kelly Cupples had,

Parks 50 $125.00 5 gal.
Parks AAA $110.00 5 gal.

Kelly Cupples / octihunter@charter.net
2807 Butterfield Rd.
Yakima Wa. 98901
509-949-5231

Steve Randall
09-26-2010, 09:43 AM
I also contacted a local sales rep. for Houghton to get a price on there K quench it was 175.00 + shipping ....steve

RodneyJ
09-26-2010, 02:07 PM
Thanks Kevin the pictures realy helped me to understand more of what i have been reading.
Thanks and God Bless
Rodney

son of liberty
09-26-2010, 04:53 PM
I saw the group buy at blade forums.

Kevin R. Cashen
09-26-2010, 05:27 PM
Thanks Kevin the pictures realy helped me to understand more of what i have been reading.
Thanks and God Bless
Rodney

Why thank you very much yourself Rodney for the kind word, you are most welcome.

RodneyJ
09-26-2010, 07:55 PM
Recently I contacted a Houghton dealer about a Med speed oil and the quoted price was actually half that.


Seth

Do you still have a contact number for the Houghton dealer? I went on line and tried to find a dealer but have not gotten a response yet may need to try again

Seth Howard
09-27-2010, 11:31 AM
I used the contact number on the Houghton webpage. They put me in touch with a local dealer. They very nice and helpfull.


Seth

Troop
09-28-2010, 04:34 PM
Kevin, please let me know when you get the formula down; I would like to buy 10 gals. or so.
Thank you,
Mitch

Leatherface
09-28-2010, 06:26 PM
I also contacted a local sale rep for Houghton to get a price on there K quench it was 175.00 + shipping ....steve

we has a local rep? where be the rep?

huh?

gnique
09-29-2010, 06:27 AM
This thread seems like an appropriate place to ask a question that I have wanted to ask for a very long time. I bought five gallons of CLC Quench K 186. I bought it because I really didn't know any thing at all about quenchants (I still don't). All I knew was that I thought that I wanted a fast oil. I called and talked to the guy who OWNS the cotton pickin' company and explained what I wanted. He sent me this stuff. It seems to me like it works just fine but I really don't know. The technical data sheet that I received with the oil said that its quench speed is 190 ft/sec. How does that equate to 9 seconds? I have read a lot of material about quenchants so I know a lot of stuff about what is supposed to go on down at the atomic level and all of that but I can't see them liddle buggers. My O1, 15n20 and 1095 blades skate a file, they take and hold an edge, they flex over a brass rod. I looked at Kevin's micro-graphs on this thread and I have just got to wonder how do you ever really KNOW if what you are doing is the best that can be done. I can tell you one thing - the guy at CLC is a nice guy who was very helpful to some fool out in Oregon wanting to buy five gallons of oil that he normally sold by the tanker truck load. Thanks guys. Nicholas

Kevin R. Cashen
09-29-2010, 08:03 AM
...I can tell you one thing - the guy at CLC is a nice guy who was very helpful to some fool out in Oregon wanting to buy five gallons of oil that he normally sold by the tanker truck load...
This is a pretty important thing that should not be overlooked, this attitude is rare in industry which has always made it difficult for knifemakers. The ft/sec. vs seconds in cooling time is one such example of different tests and concepts of speed used by industry and making it hard to compare products. Some oil guys base it on viscosity and not cooling rate, and although the two are connected they are not synonymous. O-1 requires a different speed oil than 15n20 or 1095, the later two are the ones that need fast oils.

How do you ever really know if what you are doing is the best that can be done? It is easier than it sounds, and it doesn't require microscopes. Set your own goals and standards and relentlessly work toward them. Do not get hung up on perfection or 100% levels that really cannot be obtained. See if your knives hold the edge you are happy with, that is really ultimate test and goal after all. The brass rod test thing would require a thread unto itself but in short it is more affected by the edge geometry than by heat treat and thus can tell you nothing about how much pearlite you have mixed into the martensite that is skating a file.

One test that is an industry standard, works rather well at detecting that nasty stuff as you can see from my image, and is fairly available to most knifemakers is a Rockwell tester; if a knifemaker doesn't own one the chances are very good they know somebody who does. If you don't have a tester in your shop you don't need to Rockwell every single blade, if your heat treat is consistent just a test sample every now and then will tell you that you are still on track. However it is that little caveat of "consistent" that makes things like quenchants designed to be very stable over the long haul so critical.

SteelSlaver
09-30-2010, 06:34 AM
One of the greatest tools I have gotten for my knife making is an Ames portable RC tester. Small easy to use with a little practice and amazingly accurate once I got the hang of it. I got mine off Ebay for about $150. Make sure it comes with the diamond penetrator. Mine did not, but luckly the seller got it for me. I have learned a few lessons with it.