Quenching indoors?

shortyg83

shortyg83

Joined
Feb 24, 2014
Messages
105
Ok so I am making some small knives mostly out of files and such. I am going to quench in either peanut oil or canola oil but I am curious if it is safe at all to do indoors.

Can I use say a large pot with maybe a metal lid and then have a cut in it to place the knife in so that that the lid hopefully blocks spillage? I know the oil should be heated to about 140f but I am just curious how big of a flame I am likely to see from this with these oils.
 
Sure it’s safe to do indoors. As long as you have cement floors and adequate ventilation, you’re good to go! I do it in my garage all the time.
 
You need a fireproof location with no flammable ceiling. You need excellent air exhaust and fresh air return. The room will smell like quenching for a good while, too.
It can be done indoors in a proper shop, but I would not quench in a house, or a garage attached to a house.
 
For years I used an ammo can filled with about 25 liters of Canola oil for quenching. Heated to about 55 degC. The flame action was pretty anticlimactic I must say. More of a frzzzt. No Backdraft-esque action in sight, at all.

I'm not saying it couldn't happen though, especially with less oil. Stay safe.
 
How/where are you heating the blades? I'd probably be more concerned about that than the oil.

As long as you do a full immersion into the oil, and don't pull out until the steel stops glowing, you shouldn't see much of a flame up. The reason you see big fire balls on shows like Forged in Fire is because most of the smiths aren't submerging the handles, which are red hot and ignite the vapors in the quench oil.

If you get a big flare up, just drop a non flammable cover over your quench tank for a few seconds.

FYI, it's still a great idea to have a suitable fire extinguisher within reach whenever you're doing hot work.
 
Drew Riley said:
The reason you see big fire balls on shows like Forged in Fire is because most of the smiths aren't submerging the handles, which are red hot and ignite the vapors in the quench oil.
Click to expand...
I'd been wondering why they got so many flame ups when I seldom get any flame to speak of here at home, but I'm submerging the total blade. It makes sense as I suspect they're not wishing to harden the tang for easier drilling later when they didn't have time to drill in first round.
 
I think that since you are asking then you already know it can be very dangerous.
Many of us do it, but it would be a dangerous lie to say it is safe.
Prevention is the key, addressing each one of the potential risk...
Fireproof as much as possible is the requirement of the sorrounding area, up to the roof.
Ventilation and air change for the CO2 and the nasty smoke.
Just a metal lid to close the metal tank after the quench in case the oil catches fire is mandatory; no air, no fire.
Be sure you cannot tip the tank, which is the main danger here; having it fixed to a wide heavy base is not overkill imho.
For the accidental oil spill containment a bottom metal vessel would do the trick.
If someone has more ideas from experience it could be a good idea sharing here.
 
GoldSkula said:
Very well said.
Only tip I have is to fill the oil tank only ~70-80% full so you won't have spills so easily.
Click to expand...

You are right, bubbling, agitation and thermal expansion can add together to make a big mess if you have your level too high in the tank :)
 
If you think its a bit dangerous its best to re think a new solution. . Very much thinking where your heating them though and with what
 
I quenched a seax last winter and had some oil spill on the concrete. The handle didn't fit all the way in the ammo can and flared up. To say I was starting to panic would be an understatement. I decided I wouldn't quench in my shop until I had a good fire extinguisher. It could've went really bad.
 
The recommendation is to have two fire extinguishers. They should be at least 5 pound size, and 10 pound size is much better. A nearby water hose is also wise (not for the oil, but for everything else the oil may ignite).
 
Patrick - Do you use one now that you can recommend?
I haven't heard of any that have gained popularity. I asked several of the major guys and all said polymers have too many issues.
 
Stacy E. Apelt - Bladesmith said:
Patrick - Do you use one now that you can recommend?
I haven't heard of any that have gained popularity. I asked several of the major guys and all said polymers have too many issues.
Click to expand...

A few years ago I talked with reps from Houghton and settled on the #3699 formulation. 99% of my heat-treating is outsourced but the 3699 works fine for me, in the sense that I get ideal post-quench hardness levels as confirmed with a tester. https://www.houghtonintl.com/en/products/aqua-quench®-3699
 
You must log in or register to reply here.
Back
Top