Parks 50 and big flame.

quint

quint

Joined
Nov 29, 2011
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So as much as I have used parks before I have never had a flame more then a small little guy, maybe half a foot or so. Well today while quenching some blades I had a really large flame that errupted and engulfed my hand and was some what difficult to put out. My tongs which are a couple feet long were totally engulfed. Had to take the blade and put it in water with the tongs to get everything to go out. Have never had this issue before.

Would this be contributed to warmer weather or just the parks starting to get old, or is this just pretty common and something that I should watch out for.

Thought maybe it was because my tongs were to hot but they werent in the flame the entire time which I have done before and not had this issue.

Thanks for your inputs. Oh and remember safety first lol. My hand is reminding me of that.
 
Not throwing salt in the wound by any means but... always wear gloves and have a lid big enough to cover the quench tank near by.
Ok, safety covered, is there any chance you got water in your quench oil? Or is there also the possibility that your temps were too high? Doubtful the warmer weather changed much, or at least enough to cause that. I usually associate that with water in the oil flash boiling causing an eruption of oil that is already heated to the flash point. Add air to complete the fire triangle by atomizing the oil with the boiling water and poof...
I know it was probably a holy sh*t moment, but provided your butt wasn't swallowing your fruit of the looms, could you tell if it looked like smoke coming off and burning or if the oil was splashing up from boiling?
 
Thanks for the safety suggestions and I totally agree. I wear gloves every single time except this time and I learned my lesson. Always seems to happen the one time you forget about safety.

You know now that I think about it there was a certain amount of condensation and I am wondering how much had actually accumilated on the oil. I noticed some under the lid. Didnt notice how much smoke was there but it was enough to be annoying after wards.
 
I can't remember the ratio of water in oil that would cause said effect, but I think it was quite small. That would be my guess for a culprit based on your description.
 
Did you leave some part of the red steel out of the oil, like keeping the tang un quenched?

In quenching you will vaporize some oil.
Leaving a red hot tang exposed lights that vapour like a match.

If you do a full quench, that effect is reduced.



Water definitely will cause flare ups, just deep frying french fries can practice that sort of thing.
 
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Exactly what I was thinking with the smoke question. If you could tell that the smoke appeared to be burning above the oil surface it is a good chance that was what was happening. I.e. vaporized oil was being ignited by an outside source such as exposed red hot knife or tongs... If it seemed to just explode up out of the oil my bet is still on water in the oil. If that is the case, there are products that can mitigate it, but I would say ditch it for new. (Properly recycling of course... lol)
 
Good stuff thanks guys. Ill do some "controlled" trys in the future and see what I am running into. 1-10 I know what your talking about and have done that before but even then it was usually just the small flame and I would put it in all the way, this was pretty crazy. Ahh well the adventures of knife making.
 
You had something hot enough to ignite the flame on top of the surface of the oil.

Most likely, it was your tongs. If you were holding your work piece in a forge with your tongs the whole time bringing it up to temp, especially if you did a thermal cycle before hand, without quenching your tongs, that's the likely case.
 
Thats a possibility, but certainly not the only way this could happen.. If there was a very quick flash boil of water suspended in the oil, this would cause the stated fire even if the tongs and work piece were fully submerged. It works much like the vapor jacket in a water quench, except this allows room for the oil to atomize and a route for rapid oxygen induction thus completing the fire triangle below what would be the "surface" of the oil. Usually a hot tong above the surface causes a small flame and not the violent eruption he stated.
Based on the discovery of condensation under the lid, I tend to think suspended water is still the most likely candidate. This is, among the many reasons not to, the number one reason to avoid used motor oil as a quenchant...
Think frozen turkey into cooking oil (and youtube search it if need be) and you will see that less than an ounce of frozen surface water on a turkey dunked into fry oil will give you a nice 10 foot flame. Think what even a fraction of that water could do... In the turkey case, the burner is the heat source, but with a quench, the work piece and tongs are the heat source now exposed to atomized oil by the flash boil.
Good luck, play safe...
 
Never preheat 50 if ambient temp is "normal." That means if it ain't cold, don't do it.
 
Thanks for the insight guys. Ill keep a very close eye on the next heat treat cycle and be darn sure to wear my forging gloves.

JDM I have always read that parks should be around 90 degrees or atleast close to that. So far my garage has been in the mid 60s for a while so I usually always take a piece of steel and heat that while I am doing my thermal cycles and quench that before the blades. This usually brings the parks up to relatively warm to the touch and seems to work great for when the blades are ready. Ive done this many times in the past without the fire eruption that I got last time (probably the reason I wasnt to concerned with gloves although complacency can be a true b!!!! as I found out).

Javand you could be very right but would like to add that in the past I have taken my tongs and put the knife in them then taped the end of them to hold them shut. I would do this so I could leave the blade in the forge for the thermal cycles and hold time without them falling over. Usually works pretty good. Never an issue in the past. This time I was going in and out with the tongs and just letting the blades sit in the forge. That being said I could have gotten it right before when doing the quench and gotten everything submerged and maybe this time didnt get everything all the way in my quench tank. Hard to say, or maybe a combo of the things covered in this thread. Appreciate the input.
 
Quint, I believe that Parks/Heatbath has actually changed the working range of #50. I dont think they actually changed the formula, just expanded the working temp range, but the only extended the LOWER number which IIRC, was 70F. The top of the range is still only 120F whihc is 30-60 degrees lower than what you wouldd typically use fro medium speed oils. Just out of curiosity, how big of a qunch tank are you using and how many blades had you quenched before the oil tried to kill you?;) I have never had #50 erupt on a tip down quench. Now I have had a blade flame up if I was trying to do an interrupted quench, but it never ignited the tank. On the other hand, I HAVe had the vapor from a pan or tank of heated Tough Quench and Parks AAA flame up.
 
I was working on a knife the other day with Mason from Leethal Cutlery after he invited me out. First time quenching a blade, and I got a pretty big flame from it too... and he told me it would do this if I stuck the tongs in. The flame would have easily hit me in my face, but I just moved me head out of the way. Can't have a firefighter scared of a little flame from a bucket. :) Good thing you made it out alright.
 
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