kayakersteve

Oil Quench --- What Type to Use?

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For  hardening, what type should you use?  I was wondering if motor oil (used or new) or something like canola???   Thanks for help.

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Check out the heat treating section, this is well covered, keep off motor oils especially used, loads of additives and potential toxins.

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Every now and then I pump out a knife shaped object. I don't let any thing near them that isn't food grade. Personally a food grade oil would probably be your best bet.

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WHAT ARE YOU TRYING TO HARDEN?  Knife, sword, ANVIL. tooling?   Alloy and Size of the object do make a difference.  Do you need a fast oil or a slow one?

 

But as mentioned stay away from used motor oil; not only the toxins from quenching but it's not very nice if you plan to use a kitchen oven to draw temper.

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There is proper quenching oil. Different cooling rates. I have drums of two different grades.

Drop over and get some. :) :)

 

Neil

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used fry oil is generally ok; you will want to use it warmed to about 140 degF  Should be OK for 5160---what size item?  You will need a LOT of it for large items.  Beware of flare up when quenching hot steel---get in under the surface fast!  Make sure it's in a metal container and have a lid to cover it to put out a fire.

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If you search the forum using the keyword quenchant you'll get a lot of good hits including ideas for a quench tank.  Learning how to use the search facility makes everyone's life easier.

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I use canola to quench my 5160 blades.  If it's fairly new and clear, should be good; if it's dark and kind of murky, better to get fresh.  Preheat a bit to around 120 to 130 Fahrenheit.  You can also use mineral oil, and preheat closer to 150 to 160.  The mineral oil's a bit faster, but canola seems to harden nicely on 5160.

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Thanks for responses everyone.  I lost the thread after it was moved.  This is indeed for blades and thickest would be around 3/16".  I have an old CO2 tank from mig welding that has been retrofitted into my quench tank.  Have been using used motor oil, but you guys have enlightened me and I will be switching to canola most likely.  Tank holds around three gallons, so the commercial ones can get pricey!

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Kayakersteve,

If I remember correectly  you posted this in the blacksmithing threads. I was not sure exactly what you were going to quench and I sent you a private message asking you..After a day or so without a response i moved the thread on a wild guess it was about knife blades.

A lot of folks post incorreectly in the blacksmithing area. Maybe it is because it is the first place on the home page.

A good reason to look before posting is that some folks just follow certain areas as that is where they look and respond. 

This thread had good responses and seems like it answered your needs.

 

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@moderator51 - You are correct that I seem to have posted in wrong area - I am still getting used to site and it took a few days to even find that I had a PM from you.  - I appreciate your directing me and will review more moving forward to save you guys from doing uneeded work.

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here are a few quenchants and their relative speeds

  • Brine, 5-6 seconds

  • Canola oil, 10-11 seconds

  • Chevron Quenching oil 70, 10.5 seconds

  • Citgo Quenching Oil 0510, 14.5 seconds

  • Drasta 119S, 13-16 seconds

  • Drasta 117S, 8-12 seconds

  • Duratherm G, 11 seconds

  • Duratherm Superquench 70, 10 seconds

  • Gloc Quench A, 11 seconds

  • Gulf Super Quench 70, 11 seconds

  • Houghton G quench, 10-11 seconds

  • Houghton K, 7-9 seconds

  • HP Metaquench 39 14.6 seconds

  • HP Metaquench 42 14.2 seconds

  • HP Metaquench 43 12. seconds

  • HP Metaquench 44 8.9 seconds

  • McMaster quench all, 28 seconds

  • McMaster quench fast, 11 seconds

  • Parks 50, 7-9 seconds 280°F

  • Parks AAA; 10-11 seconds 340°F

 

 

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Mr. Sells Sir,

Your chart is marvelous.  Thank you very much for it.

SLAG.

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Yes, thanks much for the list.  One question of clarification though.  What does the time rating represent?  Is it time from quenching temperature to quench medium temperature or to another point in the sub-critical curve?

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The ideal quenchant is one that exhibits little or no vapor stage, a rapid nucleated boiling stage and a slow rate during convective cooling.  This is why most experienced smiths advocate the use of commercial quenchants over used fryer oils.

Quenchant speeds are a standard measurement based on the time it takes to cool a 7/8 inch (22mm) diameter nickel ball from 1625°F to 670°F (885°C to 355°C).

 

 

this has been another teaser from my new book Knifemaking 2.0

 

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But do any of the commercial quenchants make you shop smell like a deli or doughnut shop?

On the serious side. Drats, I reread your post and you answered my only serious question in the last sentence. You reading my mind again?

Thanks Steve.

Frosty The Lucky.

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