Do you think Quench oil "wears out"?

Kentucky

Kentucky

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Dec 13, 2008
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Just curious do you think quench oil wears out for lack of a better term? Our parks has been used a few thousand times, to the point that less than two and a half gallons remains out of five. Seems to still work fine. Just curious what do you all think..
 
Yes. We have a 30 gallon barrel at work and it will get to the point where it will no longer harden O1. Hard to say how long, how many cycles, as the stuff they quench in it is quite a bit heavier than a knife blank. Maxim says when your Parks is cloudy and won't settle out to clear it's time to change.
 
Doesn't Parks make a solution that perks up your oil when it starts getting old? Of course, that might not be as relevant for us as we tend to buy our oil by the paint bucket, not the tanker truck. ;)
kuraki said:
Yes. We have a 30 gallon barrel at work and it will get to the point where it will no longer harden O1. Hard to say how long, how many cycles, as the stuff they quench in it is quite a bit heavier than a knife blank. Maxim says when your Parks is cloudy and won't settle out to clear it's time to change.
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Ours is past cloudy for sure but still hardens everything just fine. best I remember I didn't take that long to get dark but my wife quench's a lot of small parts made from W1 too. That's were a lot of the use comes from
 
jdm61 said:
Doesn't Parks make a solution that perks up your oil when it starts getting old? Of course, that might not be as relevant for us as we tend to buy our oil by the paint bucket, not the tanker truck. ;)
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We only buy a 55 gallon drum at a time. One drum probably lasts 10 years, changing out the quench barrel every 5. Maybe more.
 
We need to order more. Need to build a new quench tank too..if it ain't one thing it's another
 
Phillip, the beauty of #50 is that you don't need a special quench tank. 120mm mortar round can would work. For other stuff, Home Depot sells an electric Turkey fryer now. Or you could see how a home sous vide machine works on oil. :D
Kentucky said:
We need to order more. Need to build a new quench tank too..if it ain't one thing it's another
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go to the maker's website. they all list the tests to use to determine how good the oil is. if you have lost 50% of the volume, the oil is shot even though it may still quench parts.
from the Park's 50 brochure:
CONTROL:
The quench speed of 50 QUENCH OIL should be monitored and maintained at > 30 amps at 100oF as measured using a HOT WIRE MACHINE (available from Heatbath/Park Metallurgical). If quench speed becomes lower than 30 amps, a 5% addition of QUENCH OIL ACCELERATOR will restore the speed and reinforce the anti oxidizing compounds in the product. 50 QUENCH OIL may need centrifuging or filtering depending on sediment that is dragged in. Sediment level should be maintained at < 0.5%. Absorption of furnace atmosphere can cause the flash point of 50 QUENCH OIL to lower resulting in poor quench characteristics and fire hazard. Should this occur de-gassing the oil at a temperature not to exceed 225oF will remove the contamination. All efforts should be made to avoid water contamination of 50 QUENCH OIL. Water will cause very erratic quench characteristics as well as posing a serious fire hazard.
 
Yes Ive no doubt it would be good to change it. Some lose was to spilling but over so many quenches you will loose oil no matter how much you let drip off the part.Especially with the amount of small parts she makes.. Its not from burn off I know that. Its been filtered a few times and added fresh to a few times. Still cloudy though. Need to be calling Texas tomorrow I guess
 
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What do you all think the results of a worn oil would be? slower or uneven more harsh quench???
 
Well, in my example at work, they notice lower as quenched hardness. I assume it's due to a slower quench speed (and they're using an already slow Quenchol). So maybe it's less noticeable with Parks being as fast as it is.
 
In swap the oil out for new oil every 3-5 years for general purposes. Usually, when draining the tank to get the clay sludge and trash out of the bottom. At the rate of quench most knifemakers do, it is far more likely that atmospheric moisture will damage the oil that for us to "wear" it out.
 
I think a lot of the cloudiness is from absorbing water, if not from the atmosphere then from condensation, and like the info on Parks says, water contamination can impact how the oil behaves. Just like starting your car in the winter, driving only so far before it warms up and shutting it off is bad for your oil, you want to get to operating temperature to boil off the condensation, or it turns into a sludgy mess.

I think, but don't know, that if your oil, regardless of what it is, becomes very cloudy and it's not silt/solid particulate, heating it to 220F for a while to boil off any water contamination would go a long way towards "making it right" if not "like new."

But the other side of that is that if you're not noticing deteriorating performance, does it matter? If you're relying on initial test values for your heat treating processes, ie, once upon a time with a new bucket of oil and fresh thermocouple etc, you heat treated 1500f and quenched in your oil and tempered at 400 and got 60RC, but since then you just heat-quench-file check-temper and do not RC test, are you sure you'll catch deteriorating performance 1 lost RC point here or there?

So you can "play it safe" and just change your oil out to the manufacturer's recommendations, which are likely conservative. Or you can RC test periodically to verify your original process is still meeting expectations. But I don't think it's smart to both keep going with old oil and without some kind of process verification like RC testing, as variable as the file check is.

*not directed at anyone in particular, just my thoughts on the entire subject regardless of oil type/age. Processes that were once shown to be in control left to deteriorate without further verification will fall out of control, if not from a single major variable change, then from the stacking of multiple minor variable changes.
 
Now I mostly use air hardening steel, so I'm not that familiar with quenching oil. But would it be worthwhile having a gasketed lid for your quench tank to keep the moisture out?
I'll have to get some soon for hardening Damascus, hence my asking.
 
Canola and peanut oil will oxidize faster than a commercial HT oil. One of the things added are anti-oxidizers and stabilizers. I would replace any veggie oil when it gets cloudy, smells, or is a year old.
 
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