Quenching medium questions

calharkins

Well-Known Member
I am a pharmaceutical chemist. Not to be confused with the pharmacist that just counts and pours medication. We compound medications for patients with specific needs. I was making some medication and got to thinking about things that could possibly be used as a quenchant.

Propylene Glycol is miscible in water. Has anyone ever tried adding propylene glycol to water and quenching W-1 or W-2 steel?

Has anyone tried PEG 300 (polyethylene glycol 300) mixed with propylene glycol or mineral oil as a quenchant for O-1 steel?

Lots of possibilities. I just don't want to go down a road that someone has already been down.
 
That's interesting. One concern would be the chemical stability of an additive like that during the introduction of a 1500 degree object. Does PEG degrade at high temperatures?
 
Well I don't know. I have never heated it that hot. I will do some research and find out about it's stability in high heat.
 
Surprises are called surprises because they aren't expected. I once tried to put out a campfire with window washer fluid. Whoda' thunk? :)
 
There are probably hundreds of quenchants that can be used and I doubt the end user could tell you the difference between a blade quenched in any of them. I am not sure what is to be gained by adding possible quenchants to a list that already reads like tea leaves.
 
If I can make an excellent quenchant for less than half what I would have to pay for one that would be a win for me. Besides that it gives me a chance to use the chemistry I learned. I think the first one I will try will be some propylene glycol 50:50 with water to heat treat some W-2. I am down with bronchitis right now so it may be a bit before I get to try it. Anyone got any ideas I want to hear them.

Kevin thanks for the information. It gives me hope that it will work.
 
I know Howard Clark was using a glycol mix for his sword quench years ago, I also know he is back to using water-------Man's got sand!----------glycol mix does work, just not sure about its limitations.


Peter
 
I've thought about trying DPG (Di Propylene Glycol), and/or DPG diluted with water. As far as I know it's relatively safe, though I'm not sure how it would react with the heat. It's used a lot in incense and fragrance products, also used in stage foggers and many other things.

http://www.essential7.com/carrieroils/dpg.html
 
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I did some research on propylene glycol. I have no knowledge on di-propylene glycol. Propylene glycol is unsed in topical and internal medications. According to chemical literature propylene glycol boils at 371 degrees F and poses no inhalation hazard. From what I can tell from the literature it looks like the maximum heat conductance would be when propylene glycol is mixed 50:50 with water.

Now the disclaimer! I have not tried this. I do not know if it will work. I have no working knowledge that the books are right about it not being a hazard. I do not recommend you trying this.

When I get well enough I will wear a respirator and try it. I will report my results. Now remember, I am only a part time new bladesmith. I wish I had the experience and the knowledge of Tai, Kevin, and a lot of you other master bladesmiths. You guys contribute a huge amount to Knife Dogs.
 
I'm thinking AROMATIC and atmospheric engineered quenching fluid! :)

DPG would be the perfect carrier.

... maybe throw in a light show.
 
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Kevin, have you tried any of these quenchants that were listed on the links you posted?


I have some experience with an earlier version of one of the Heat Bath products when consulting for an operation that used it. I found it more hassle than what it would be worth in my shop. Long ago I found around 4 steels that met my needs almost perfectly and outfitted my shop for the heat treatment that best suited them. All I really need is my low temp salts and occasionally some Parks #50 when working a steel that is not compatible with them.
 
Kevin, I read all your posts and even look for older posts on other sites. You are the MAN! when it comes to heat treating. I have learned so much about heat treating from you. I am searching for the steels that I want to work with. I do stock removal with O-1, 1095, and some 440C. I am forging 5160 and have been forging some 52100 I bought from Ray Kirk. The wife keeps grabbing up the 52100 knives and saying they just fit her hand and so they go to the kitchen. I guess I better forge some bigger blades from the 52100. I bought some W1 from Aldo when I was at Batson's. I want to try to forge some of it. I was just a little afraid to try straight water and I thought of the propylene glycol. I am going to keep all the data and I have a friend that will check the hardness of the blades. It may just be a waste o time, but I have wasted a lot of that. I just joined ABS so I need to do a bunch of forging to try to get better.
 
Here's a few more numbers to consider on the DPG. They seem on the low side for a quenching oil. Thinning it with water 50/50 might be too severe, but might also raise the flash point (good)... and lower the boiling point even more (not good).

Viscosity- cP @ 25ºC- 75

Boiling point- 446.9 degrees F

Flash point- 249.8 degrees F

... Looks like a real fast one to me,... maybe already too fast for anything but shallow hardening steels, and even then.

(Disclaimer: I'm not a chemist)
 
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Tai, you are probably right. Flash point on propylene glycol is 228 degrees. I should have taken that in to consideration. I was figuring if it was mixed in water that would raise the flash point but probably not since it is miscible and not soluble in the water. I was thinking the propylene glycol would hang next to the blade even when the water evaporated away and would dissipate more heat. You may not be a chemist, but you sure would have made a good one. You have to look at all the variables not just one or two. I guess I better rethink this one. Thanks and a tip of the hat to Tai and Kevin and all the rest of you guys that had input on this.
 
Yep, and the viscosity at 25 degrees C (77 F) of 75 is already low cold. Warm it would be even lower. AAA is 85 at 100 F, and #50 is 45 at 100 F.

My concerns are that it might be relatively a bit slow at the get go compared to the accelerated oils (AAA, #50, (or canola)) because of the unchecked vapor phase (though agitation/circulation would help, if needed) and too fast in the low temp., transformational phase, because of the low viscosity and extended boiling phase... just the opposite of what an ideal medium should do.

Still might have it's place in "theatrical quenching" though. :)

I guess you'd have to try it to see.
 
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Sorry about all the edits,... just trying to figure it out and get what I'm saying to make sense.
 
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