Quench oil question

Hello everyone, I was just wondering if anyone here has ever experimented with using used "full synthetic" motor oil as a heat treat quench oil for hardening
5160 and the like steels? And if so what kind of results you had. thanks, Bear
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I have used normal motor oil, and wouldn't see the point of wasting good synthetic oil instead...
Having said that, I recommend Peanut oil, which you can purchase at WalMart or anywhere convenient. It has a high flash point and doesn't smell so bad when quenching.
John P.
On 13 Mar 2006 06:43:38 -0800, snipped-for-privacy@yahoo.com wrote:

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No matter what you use, make sure that it has no water in it. If in doubt, heat it to about 220 degrees F and then let it cool before using. Maybe that goes without saying, but if a red hot part hits water, you get a dangerous burst as that water turns to steam. Wear eye protection, at the very least.
I hesitate to give advice about the oil. There are many variables that go into heat treating. If you are making a cold chisel, I doubt that the type of oil you use could do much to change the results, since you ar probably guessing at the quench and temper temps anyway. If I knew you were making a high quality knife, I wouldn't even say that much for fear of the reprisal that I would suffer in the face of the experts. I know a guy would never use anything other than peanut oil. Another uses olive oil. Many people just try a thing and, if it works, that's what they do. I have read that synthetic motor oils can take higher cylinder wall temperatures than "natural" oils. So, at least, I'd assume that it wouldn't be any worse at decomposing than used petroleum motor oil.
Pete Stanaitis ------------------------
snipped-for-privacy@yahoo.com wrote:

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DAGS on this group - there are some excellent reasons to avoid _any_ motor oil (or perhaps just any detergent motor oil, which is any motor oil that does not specifically state "non-detergent") as a quench medium. I recall reading them but don't immediately recall the specifics - something with the metallic soaps interacting with the hot steel in an undesirable way.
As for used motor oil - ick. Which part of "definitely a carcinogen" do you fail to read, much less want to breathe in fumes from?
Peanut oil for the high flash point and easy availability (with better smell), or quench oil (supposedly not too hard to get from any oil distributor) for even better flash point behavior. And you still want both enough oil that flashing is unlikely (lots of oil relative to hot steel means the bulk of the oil does not get too hot), and a tight-fitting metal lid for the metal container so you can put it out when it does flash. Make that container very hard to tip over, too.
--
Cats, coffee, chocolate...vices to live by

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snipped-for-privacy@yahoo.com wrote:

DON'T. Automotive petro products contain metallic soaps that react chemically with the work at temp, contaminating the steel. I use vet grade mineral oil, available at your local Feed & Seed type stores, usually for about $10 a gallon. It will flash a bit until the work is totally immersed, wear gloves and eye protection. Once the work is completely under, the fire goes out. Hold it under until you stop seeing obvious convection at the surface. On 5160, you can get up to about Rc 62 full hard starting with room temp oil. My quench tank is four feet of six inch pipe and I use a vertical point first quench. I can usually get three swords through the tank before the oil gets really hot and the hardness starts to fall off. Cold oil gives a harder workpiece than hot oil. Having done over 100 swords and Bhob knows how many knives, the results are quite consistent, and the scale rubs off with a shop rag while the blade is still warm. Mineral oil will take the work down to black in less than a second from 1600F red, and wets quite well, no vapor sheathing.
Happy whacking...
Charly
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Thanks muchly for the advice,
I will tell my Dad to just send the used Mobil 1 that he was saving for me to the recycler,, I was afraid there might be a situation like the higher boiling point of the synthetic oil making it bad for a quench oil,, I hadn't even thought of the detergents and other additives in it.
As for the safety issues, I'm damn near 50 now and have been a machinist all of my working life,, I've been called a " saftey fanatic " by more than one person before,, but then I still have my eyesight, hearing, and all of my fingers,, if it takes being a fanatic to keep it that way, so be it.
thanks again, Bear
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snipped-for-privacy@yahoo.com wrote:

The safety blurb is reflexive, you never know who might read the post; don't take it personal. I too learned a loooong time ago to keep my fingers out of the fan, I've still got all of them.
Happy Whacking...
Charly
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yepper Charly, I know how that reflex is,, and it drives my stepson crazy,, he just finished his training and got his class A trucker's licence a couple months ago, and started working for a local trucking firm, if either his mom or I am awake when he heads out the door, the last thing he hears is "drive safe",, same reflex,, we both know full well that he is at least as good a driver as either of us are,, but we still do it.
Bear
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snipped-for-privacy@yahoo.com wrote:

Keep it up. The one and only time I forgot the 'drive safe' charm, the old lady's car burned to the ground on the side of the road. Wiring under the dash, she got out okay but the car was totaled.
It really does work...
Charly
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What happens when you forget to say "God bless the USA" ??
wrote:

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Eide wrote:

Say what? I don't indulge in politics, too much like religion for my tastes. That reminds me of the afternoon that the JWs showed up in my shop while I was making a billet. Thay asked me why I made swords, and I told them that there wasn't much call for plowshares these days, and a man has to stay busy. They left scratching their heads, and I went back to work. Just another day in Babylon...
Charly
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Charly
Do you have any pictures online of your swords? I would very much like to have a look at them. Do you use leather to bind the grip and make the scabbars?
Cheers
Niko
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Niko Holm wrote:

Sorry Niko, no way to get them into the web. The grips are usually hardwoods bonded with epoxy and banded with brass at both ends, just to be sure. Scabbards are 12-14 oz veg tanned leather, stitched with .032 aircraft safety wire and dyed USMC black, then soaked in the mineral oil quench tank to 'prime' them. Not all that fancy, but very functional.
The blades are machined from virgin SAE 5160 stock. Blades are 30" long, 2" wide and .290 thick, full tang. This gives a weapon that's 35 3/4 long overall. Hardware is either mild steel, 304 SS, or cable damascus, depending on the customer's desire and wallet. Blades are heat treated to Rc 55, +/- 1 point (computer controlled oven). All blades are tested against 12 ga steel before final assembly, any damage or marring and it goes in the scrap pile. This is a dimensional replica of a 10th C Juttish long sword, optimized to take advantage of modern materials. They will pull 45 drgrees out of true and spring back, but you'll need a comealong to do it and a really sturdy vise. The only thing I won't guarantee them against is a train running over them. Turn your coupe into a convertible in a half dozen good strokes. The current 'high score' is felling a four inch diameter oak tree in a single stroke. Granted, the fellow that did this was a Large Lad, but that's a fence post in anybody's book. The math says it will take 37 tons of shear loading before structural failure occurs at the shoulder. I don't think there's anyone alive that can put that much force on it with muscle power.
Charly
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