Accurate oven temps?

[sharpstick]

Hello all, Anyone who uses their kitchen oven for tempering may be interested in this. I was watching a cooking show on the local PBS channel today.

The host conducted a test of about 10 different home ovens for cooking temperature variences. He was using some kind of heating core that attaches to a control box and then into a computer to get accurate results. He tested the ovens at the manufacturer set temperature of 350 degrees. What he found was all of the ovens were off. The temperatures ranged anywhere from 320 degrees to 390 degrees. The closest was only 8 degrees off.

He suggested buying an inside the oven thermometer (about $10-20 depending on brand) to get the most accurate results. I am sure most of you already knew this, but as a newbie I found it to be helpful. I had been tempering some steel at 400 degrees and no telling what the actual temperature was.

 

[Todd Robbins]

I have been using my kitchen oven for several years to temper my blades, and mine is off about twenty degrees if I set it at 375 ( It actually gets to about 395 on a thermometer). I bought a thermomometer to put in it on the advice of another maker. Stangely enough, my Mom's gas oven is much closer than my electric one, but the temp in it is less constant, for some reason (it varies about 7 or 8 degrees either way, several times during a 2 hour tempering cycle).

 

[rlinger]

Absolutely correct. I have an oven thermometer that I have tested against my Evenheat and they track. I paid, as I recall, about 3 1/2 or 4 bucks for it. It proves my kitchen oven is way off - much more than the tolerances you stated. Toaster ovens are also not to be trusted. A simple expenditure solves the problem: an oven thermometer.

When you set the oven dial to 400 F. and the steel comes out with blues and purples you gotta know its off.

RL

 

[itrade]

Warning!!!!

I ruined 3 blades before I discovered it was the kitchen oven that hosed me up!

It turns out that even when my oven thermometer said the temp was correct - my oven spikes in temperature - when I'm not looking. Enough of a spike to soften the blade too much.

A friend gave me an old beat-up toaster oven. That thing is spot on and no spikes. Now everything is fine.

I'm not saying all electric kitchen ovens do this, just saying that mine did.

So, use a thermometer and also pre-heat the oven for 10 minutes or more before putting the blades in. And still you might get toasted (pun intended).

Steve

 

[rlinger]

Steve, you got me think'n - again. Kitchen ovens are large in volume, at least compared to our needs as knife makers. I use either my new-fangled toaster oven or the Evenheat for tempering these days. It might stand to reason that a large area would spike, as you describe it, and also show lows because of hysterises (that one I know has to be big time misspelled!).

Good point Steve. One I had not considered but think I have noticed.

RL