Heat treat question

[Chris Railey]

Ok, at the risk of starting a firestorm of people throwing stones at me here is the best video I can find. This video shows Recalescence because it is easier to see. As the blade cools you will see a darker line pass across the steel followed by a brighter line. Decalescence is the opposite. As a blade heats you will see the bright followed by the darker shadow. It will be harder to see because its in your forge but seeing the recalescence helps you know what to look for on decalescence. I explain things simply because that is how my mind works. Everyone hold your fire please.

 

[Freedom Blades]

Hey man I appreciate you being so kind and explaining all this to me. It’s nice to have someone be cool and explain rather than get mad and say use the search button. It’s greatly appreciated.

 

[Chris Railey]

No problem, I still actually know very little compared to others but I try and help where I can. I remember about 12 years ago when I first started blacksmithing I joined a forum where there is a great deal of knowledge but the members are total jerks to newbies. They relished degrading and insulting them for fun. I hated it so much that I completely left forums for years until I stumbled on this site while doing some research. The members here really like to help, so I stuck around.

 

[Freedom Blades]

Yea I have done a ton of research so far on here and love it. I mean I think I’m getting somewhere around 56 HRC. I’m just using those little files to test it.

 

[Chris Railey]

It may be a moot point but for simple HT, (in a forge) you would get better results with 1080 or 1084 and both are easy to get. But you have a kiln OTW so I guess no worries. Here is the best site for new people to dig around on in my opinion. When I forget what a word means or just want to double check what I think I know this is where I go. Plus Kevin is a really good guy and on this forum a lot.

Bladesmithing Information

cashenblades.com

 

[fitzo]

Every time you open the door to your kiln the temp will drop a couple hundred degrees. Then it will have to come back up to temp. Do you really want 4 of those 5 blades in there doing a yo-yo with temp while you quench the one before it?

My advice: heat one only, hold, quench, put the next blade in, heat back to austenitizing temp and hold, etc.

 

[tkroenlein]

Yup, @fitzo is right.

Doing multiples really does present a myriad of ever increasing variables to control. You're way far ahead to do one, and work up from there as your process and equipment allow.

 

[billyO]

One thing you can do to cool your oil if it starts to get tooo hot is to drop a frozen water bottle into the hot oil to cool it down. Just make sure it isn't hot enough to melt the plastic, or use a metal water bottle.
You should be fine doing 2 blades at a time, if you're not dilly-dallying, the door is only open a few seconds and there's not much temperature swing. I've done batches of three, but I've got a 5 gallon can of Parks50.

Here's a recent article that might help you decide if canola oil is worth the effort:

Which Quenching Oil is Best for Knives? - Knife Steel Nerds

Which oil to use for quenching knives? Does quenching too fast ruin knives? Can you save money and use canola?

knifesteelnerds.com

or a video version:

 

[Chris Railey]

Yep, its time to upgrade my quench oil. In my mind (shallow as it is) there was a progression to be followed when learning how to HT my own steel. First you have to 100% know what steel you are using and how it should react to the treatments when they are done correctly. Second, you have to have good time and temperature control before you can achieve repeatable results. Third you need to use a quenchant that will do what the steel needs to harden completely. The second step for me was not cheap so it took a while. Absent one of the first two requirements the third does not mean much. So since I was doing simple HT in forge there was no big reason to obsess over the oil. But now I have the first two covered so the last piece of the puzzle to achieve repeatable results is a proper quench oil. So Parks 50 is OTW. Next will be a Rockwell testing machine.

 

[DustySerpa]

No I use pre-heated Canola. It's funny you should ask though I was just looking to order some P-50 or similar. Know a good place?

I got AAA from here, but they have 50 as well:

50 Quench Oil

DuBois is a specialty chemical company that sells and services sustainable cleaning solutions to the manufacturing industry.

store.duboischemicals.com

AAA Quench Oil

DuBois is a specialty chemical company that sells and services sustainable cleaning solutions to the manufacturing industry.

store.duboischemicals.com

 

[scherf68]

I got AAA from here, but they have 50 as well:

50 Quench Oil

DuBois is a specialty chemical company that sells and services sustainable cleaning solutions to the manufacturing industry.

store.duboischemicals.com

AAA Quench Oil

DuBois is a specialty chemical company that sells and services sustainable cleaning solutions to the manufacturing industry.

store.duboischemicals.com

Wow, good price and shipping is low on Parks, just might get some.