Heat Quench Oil

[TekSec]

Okay, I've read to just take some hot steel from the forge to heat your oil / brine. What is the best way to get the oil up to temp for quench (O-1 primarily). Thanks...

 

[Robert Mayo]

I preheat my oil with a scrap piece of steel.

 

[mdoyle]

TekSec
I have read that it its better for the life of your quenching oil if you heat your oil up slowly. My quench tank is metal, so I use the side burner on my gas grill on a low flame. If you are not using a real quenching oil then you probably aren't worried how long it will last and the method Mr Mayo described is well accepted.
Matt

 

[mete]

Yes , what destroys quenching oil is the repeated effects of putting 1500 F steel into the oil !! Proper quench oils are designed to resist this ,another reason for their use. Use an immersion heater or an outside source. All you need is about 140 F.

 

[Karl B. Andersen]

I use a store bought electric two coil burner.
One you might use out on the picnic table with a drop cord.
Dial control for each burner.
I suspend a thermometer in the oil.
Heats up 5 gallons of oil in about 20 minutes - easily.

 

[TekSec]

Thanks, guys. I was going to go with the immersion heater, but the ones I've seen looked like they were for water so I wasn't sure they would work. Just wanted to make sure!!!!

 

[langchop]

They should work fine in oil. Im not sure if you're talking about the immersion heaters that are attached through a hole in the side of the tank or the portable drop in ones, but probably the most important factor will be to check the seals regularly to check that the oil is not softening the seal material.

Lang

 

[Stacy E. Apelt - Bladesmith]

I've posted this before, but it has been a while.

http://www.bladeforums.com/forums/showthread.php?t=396477&highlight=heated+quench+tank

Here are some photos I had in the files. The ten gallon unit has a hookup for a recirculation pump and an oil cooler.

Stacy

 

[lcf]

Tecsec
I agree with Mete, use an outside source of heat to bring
your oil up to temp. Also check your thermometers, to see if they are acurate. I used three different ones one day and one read 110,130 and 90. they were all good (brand name?) makes you wonder? As a test find a hosp. type therm, that reads to 120, put it under your water faucet in the bathroom. This is low teck I know, but when water goes from 120 to 140 your finger will go from thats ok to thats hot! Just be cautious of thermometors they lie. Hi teck is a temp read out gun,
mine from msc was 250. but I use it for everything, from
forge temp to steel temp. But remember it only reads the surface of the material. Hope this helps.

 

[R. Mark Lee]

I use a meat thermometer to check the oil is at 140F (same temp that meat is completely cooked). A quick way to verify the thermometer is accurate is to place it in a glass of ice water that has sat undisturbed for about 5 minutes. Once the water and ice have reached equalibrium (about 5 minutes for a 6-8 oz glass) then the water should stay at 32F until all the ice melts, or the glass is distrubed (ie, stirred or held, ect.) If there is an offset at 32F get a new thermometer.

 

[fitzo]

The ice/water equilibrium is an excellent single point test. (Make sure it sits a good while while before you test, though, as Mark said, because it will be much colder initially, as freezer-ice temps are substantially below freezing, usually.) Even better is to use two calibration points. This will tell us whether there is a high likelihood of linearity between the test points and slightly beyond. The best additional test available in the kitchen is to use boiling water. Distilled water is best. It should be boiling "vigourously" to get the most accuracy.

At sea level, it should read 212*F, of course. BP changes with altitude (elevation). Here is a chart to help:
http://www.apo.nmsu.edu/site/directory/kloomis/bpH2O.html

If you know your thermometer is accurate at those two points, it is most probably accurate at temps in between.

 

[TekSec]

Does anyone have a good link / model for an immersion heater? Thanks for all the great info by the way...

 

[Stacy E. Apelt - Bladesmith]

The type you want is called "over the side". You don't need a huge one, do some searches and see if you can find a simple cheap one rated for oil.
Here is an industrial supplier:
http://www.chromalox.com/products/prodinfo/en/gsgt.html
here's another:
http://www.morelectric.com/lab.htm
Stacy

 

[Fox]

I went the cheap route. I use an electric BBQ starter. I hang it from the side of my quench tank and use it to stir the oil every few minutes. I use a calibrated thermometer and suspend it in the oil. It takes about 20 minutes to heat the oil. I think I paid about $10 - $15 for the starter.