Heat treating oven question

B

Brekfast

Joined
Dec 9, 2005
Messages
57
Hello,

I would be able to buy a used ceramic oven. This one was made for pottery
can reach 2300 F .

Would this work for heat treating blades ? I mean it's bigger than the specific knife ovens but it can reach the same temperature.

Than you.

Henrik
 
The hard thing to deal with in most pottery kilns it that they top load, which makes it hard to get the blades out quickly to quench.
 
2300 is more than adequate for heat treating. For example, O1, A2, need to reach 1500, D2 about 1800F in order to reach critical temperature. The important question about the oven is the removal of the blade (front loading is a good feature, butI'll get into this later) and the consistancy of the temperature as real heat treat ovens have computer controled sensors that regulate the temperature which is important. About loading and unloading, the quickness of the quench is realy only important when using steels like O1 or 440C (which can also be quenched in air), where there is a quenching medium. steels like A and D use air as a quench, so there is no need to 'quickly' remove and quench. then there is the tempering stage (oh so important) where you will need to regulate the temperature at a specific temperature for several hours (even overnight if you want) to get the specific hardness you desire. If you have any specific questions about what temps for what steels for what hardness, I can help you out.

Cheers,
a
 
Truth be told I have not made a single knife yet. I have almost finished my grinder and from what I read here I need to have some sorta heat treating facilty set up in my basement workshop so I can do stock removal and the heat treating.

I have never done heat treating either that is why I am asking about it.

About the quickly removing the knife frolm the oven bit, how does a top loading oven interfere with that ?

Your help is much appreciated !

Thanks.

Henrik
 
Henrik, with a top loader is that you will have to build some kind of rack to hold the blades so when you remove the lid you can reach in and snake out the blades with a wire. When you use a foil pack you will have to fold in a wire loop at the top so you have something to hook to. The problem with a kiln is the temperature control. 50 F can make a difference. It is pretty easy to rig up a small controller to the furnance elements to improve the control. I "adapted" a kiln to make a furnace and used it for about 5 years untill I built a custom furnance that is a lot better for what I do. Note furnace not "oven" when you are talking about these kinds of tempertures... You can contact me for more specific info and I have a short article on heat treating on my website... Phil
 
You may also want to check on the ramp-up time on a pottery kiln. most have much larger interior dimensions than needed for knives, as well as most pottery is fired for longer periods of time. Both of these might end up with a kiln that takes a very long time to get up to temp since you need to do all the work heating all that volume that isnt used.

I personally wouldnt want to reach into a top-loading kiln to grab a blade....
 
Yes I have seen it, downloaded the pdf file too.

I am still debating on wether to build it or not. Constructing the box would be simple enough, but getting the right electrical components could be a problem. Or I am just scared to dive into it hehe .

Henrik
 
Henrik,
Now that your grinder is nearly finished I suggest that you make a set of knives and send them out for HT the first time around. You can get into doing your own HT later.
I was in Montreal until this past June. I sent mine to Rob! (from this site). He is at Ranger Original in Alberta. I got a set of 12 knives done for a decent price and I'm happy with how they turned out. If I waited to do my own HT I still wouldn't have finished a blade!
 
Hi Richard,

Once the grinder is done (I still need to drill out the base plate and the support legs and attach it, set up the motor mount, have a 220 plug installed in my basement and attach the 10' contact wheel to the tooling arm .. oh yes - and by belts !) I will definitely start learning the grinding. Just the same though I'd like to either buy or make a HT oven. I find the shipping part very cumbersome. I think there is a place in Ontario that does Ht-ing as well, still it is a pain. If there was someone in Montreal to do it, that would be different perhaps.

I do think however that building that oven would be considerably less complicated then building my grinder.

lol I may be wrong though :)

Henrik
 
I dont see why there wouldnt be a HT place in MTL. They have tooling shops and manufacturing dont they? All you'd need to do is sort out the HT specs and send it out.
 
I could not find an aluminium pulley in the city for my grinder, no place to buy 2x72 belts (had to mail order it frolm the US or have a machine shop make it here for $80/hr ), I would be suprised if there was anything in the way of heat treating shops. There is at least one other Montrealer here on the board, he sends his blades out to Ontario I think, but the last time we spoke he was pretty fed up with it and was looking to have it done at home. Up here we just don't seem to have the knife making culture that evidently exist in the US.

We do have friendly people, great restaurants and nightclubs though ......


Henrik
 
Re belts: Rob at Ranger original also sells belts. I got mine in 2-3 days with Canada post.

"Miden" on this site is also from Montreal, I forget what he is doing for HT (he mentions in some posts).
 
David Schott said:
You may also want to check on the ramp-up time on a pottery kiln. most have much larger interior dimensions than needed for knives, as well as most pottery is fired for longer periods of time. Both of these might end up with a kiln that takes a very long time to get up to temp since you need to do all the work heating all that volume that isnt used.

I personally wouldnt want to reach into a top-loading kiln to grab a blade....
Click to expand...

I use a Paragon Fusion 7 glass fusing kiln. It is a roomy top-loader that goes up to 1700 F. I heat treated my first knife (O-1) with it. It really was not that bad to reach into (with the tongs.:D )You are right though, it takes a while to get it up to temp and there is quite a bit of room to spare.
 
I have a smaller pottery kiln with about one cubic foot of space.It is hexagonal.I have been planning on converting into a salt pot. I may do an experiment with it first. What if it is set on its side and used as a front loader? The knives can be placed in a vertical rack and would be easy to remove. I may try this in a couple of weeks and see what happens.
Stacy
 
Just finished the oven in British blades. Just follow the instructions. It really went together nice. It will get to 1500 degrees in under 10 minutes. Now i need to sell my lost wax burnout oven.
Take Care
TJ
 
I made a longer version of the british blade plans oven. My oven will go up to 2300 F in about 8 minutes. 28" deep, 220 volt, dual element, with digital control. If I remember correctly when completed total cost was around $180. Digital control is nothing fancy but has set points and works well, and I'm pretty sure the place I got it from is in canada. If you decide to build one and want a list of suppliers pm or email and I'll dig up info.
 
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