Mete, Longer and multiple soaks?

Raymond Richard

Raymond Richard

Joined
Jun 17, 2001
Messages
5,705
I've been trying to avoid buying a heat treating oven by going the route of toaster ovens. Had picked one up at a second hand store and trying to get the darn thing to stay at one temp is close to imposible. Yesterday I decided that the thing to do was to see what was available in new toaster ovens. After striking out at Walmart I went to Target and found at least a half dozen different ovens and ended up getting a B&D with digatal controlls, timer, and clock for $80.00. After getting it home and using it I find out the highest temp is just 400 degrees. For tempering most knife steels thats fine but there's a few steels that I use where I like to go 425 or even a little higher.

Normally I'll run two 2 hour cycles. Say if it was a steel that I wanted to run at 425 but can just do at 400 would a third 2 hour cycle make any difference or get me closer to my goal?
 
Dang....I guess I should feel lucky....my toaster oven cost me $20 and goes up to 475 no problem. I have a nice thermometer inside...and the temp on the inside matches the temp on the outside...works every time.

**shrug**
 
First terminology - soak refers to holding at the hardening temperature to dissolve the carbides....Tempering is a time/temperature dependent process, however temperature is much more significant.So an additional cycle won't help. You might use the kitchen oven[with wifes permission LOL] since it should go to 500 F.
 
I already broke the wife's oven... :D I didn't think it would make a difference but since I'm not Mr. Wizard I thought I'd go ahead and ask. Thanks alot! I'll just hold onto the second had cheapo when I need to do the higher temps since it works better at over 400 degrees.
 
Have you tried wrapping some insulation around them, Ray? Might help stabilize the temp. I don't have a toaster oven, but have read that a number of times.......
 
Guys
The easiest way to cut down temperature variations is to add mass to the oven, a piece of 1/2 X 3 stock (steel, cast iron, etc.) the length of the blade usually evens the temp out nicely. Makes the oven a bit slow coming up to temperature.

Jim
 
just to stay on topic ayehup 20 times won't change it as long as you don't go over that temp..
mine is a B&D also Ray but it goes up to 500 deg's according to the dial..it's an older joby but it works great :)
once I get the pre heat done it stays right where I put it..
it the old saying , they don't make them like they use to,,,
though it's off from what the dial says..I do use the separate thermometer
for bigger stuff I'll use the one in the house..and still that same separate thermometer
the wife don't have a say in it..I put it in the wall so I get to use it:D
Jim has a good point also,

that works for a freezer also, it's much more efficient when it's full, so fill it with water jugs... the freezer not the oven:D
 
I've read that you can get similer results to using a higher temp by tempering longer, but we're not talking an extra hour or two, it's more like a solid week straight or longer. If I remember right, not only is it possible, but it actually gives better results, better toughness for the hardness.
 
AwP said:
I've read that you can get similer results to using a higher temp by tempering longer, but we're not talking an extra hour or two, it's more like a solid week straight or longer. If I remember right, not only is it possible, but it actually gives better results, better toughness for the hardness.
Click to expand...

I think we did that one here one time and figured what while not watched close for the long times they'd get heat spikes than was not seen therefore the temper result of course would be at a lower Rock well.
Mete will set you straight on that one I'm sure..
 
The new oven works great the way it is other than it not going past 400 degrees. Heck it will even take a 12" pizza. The main reason I got the model I did is its got a good 2" more width than the other ovens I looked at. I can live with it. Just got spoiled having the Paragon for the last 11 years.
 
There is a formula for relating temperature and time but it would take days IIRC. A toaster oven would probably self destruct over that time !!
 
Shoot, I went out a while back and got a black and decker wallyworld special for 35$, it'll go to just over 500 and won't fluctuate more than 15degF. I'll have to try the 1/2" plate in it though, never thought of that.
 
You might have to insist on using the wife's oven. The larger the cavity the more care needed to learn the various temperatures within the cavity areas. I prefer to temper in my toaster oven rather than in my Evenheat. I believe, using our equipment, the smallest oven cavity suitable to the blade size is probably best. Consistency in temperature is what we generally want. There are blades suitable for ovens with differing heat in different areas of its cavity. Placing the blade properly within can temper differently for different areas of the blade. Multiply thermometers are a good thing to use on a regular basis.

RL
 
I do a lot of my tempering in an oil bath. Nice, even heat, and the blade come up to heat quicker. And you can just use a camp stove to heat it:thumbup:
 
Bruce, Don't tell me to use the microwave, I got into enough trouble when the darn things first came out about 30 years ago trying to make popcorn in a brown grocery bag. You ever tried it? A knife that is......
 
Bruce Bump said:
It sparks like hell but tempers very quickly. Make sure Momma is out of the house first!
Click to expand...
:D :D


hey bruce
did you get my e-mail the other day??
no word back from you..:confused:
 
Hey Dan Yep I got it but had family over until now. Go check your mail.

The real problem with microwaving blades is it only works once than you have to buy another microwave. Its not cost effective if you have several blades to do. :D
 
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