Greg C. Posted October 16, 2009 Share Posted October 16, 2009 I'm going by The $50 Knife Shop method of heat treating, but I'm wondering if the edge quench does well with the toaster oven. Would be better to do a full quench, and do a full temper with T oven? Any advise for a beginner would be welcomed. Greg Catch the wind in mainsails high, Race the dark and stormy skies. Land ahoy! To port we ride, And there we drink our hearts to nigh. Link to comment Share on other sites More sharing options...
robert washburn Posted October 16, 2009 Share Posted October 16, 2009 I'm going by The $50 Knife Shop method of heat treating, but I'm wondering if the edge quench does well with the toaster oven. Would be better to do a full quench, and do a full temper with T oven? Any advise for a beginner would be welcomed. Greg The oven will be fine. Robert Link to comment Share on other sites More sharing options...
Alan Longmire Posted October 16, 2009 Share Posted October 16, 2009 The only difference you'd get between the edge-quenched blade and the full-quenched blade is that the edge-quenched will have a softer back. Seeing as how that's the entire and only point of the edge quench, I don't see a problem! Link to comment Share on other sites More sharing options...
Doug Lester Posted October 16, 2009 Share Posted October 16, 2009 The purpose of tempering is to reduce the carbon atoms trapped in the martensite thus reducing the stress in the martensite crystals making the steel less brittle. It doesn't matter whether the martensite is confined to the edge or throughout the entire blade, it has to be tempered to make a usable blade with the steels most of us use. Doug Lester HELP...I'm a twenty year old trapped in the body of an old man!!! Link to comment Share on other sites More sharing options...
GEzell Posted October 16, 2009 Share Posted October 16, 2009 Do not trust the temperature nob on the toaster oven, get a good oven thermometer... I use an edge quench most of the time. I advise quenching at least 1/3 to 1/2 of the blade width, too narrow and the blade bends too easily. George Ezell, bladesmith" How much useful knowledge is lost by the scattered forms in which it is ushered to the world! How many solitary students spend half their lives in making discoveries which had been perfected a century before their time, for want of a condensed exhibition of what is known."Buffonview some of my work RelicForge on facebook Link to comment Share on other sites More sharing options...
Greg C. Posted October 19, 2009 Author Share Posted October 19, 2009 Thanks guys. Any sources for thermometers? Greg Catch the wind in mainsails high, Race the dark and stormy skies. Land ahoy! To port we ride, And there we drink our hearts to nigh. Link to comment Share on other sites More sharing options...
Randy Scott Posted October 19, 2009 Share Posted October 19, 2009 Any sources for thermometers? Linen-N-Things till they went out of business, WalMart, Big Lots, your local grocery store; etc.. Get 2 and stick them in your tempering oven, set the temp as desired and turn it on. If both the oven thermometers temps don't match (each other), buy another till they match or are real close. It is not likely the oven thermometers will match the toaster oven temp control. Oh, try to find the oven thermometers that are small so you can get in the toaster oven in an upright position with the temp gauge visible through the glass door. Link to comment Share on other sites More sharing options...
Christopher Price Posted October 19, 2009 Share Posted October 19, 2009 I often put a thin, 1 inch thick fire brick in my oven to act as a heat sink, smoothing out the ups and downs most toaster ovens experience. Tip: preheat the oven before putting the blade in, and save yourself some trouble. And Doug, not to be arguementative, but I was under the impression that tempering changes the crystaline shape, "dulling the needles" if you will, but not "removing carbon"... The Tidewater Forge Christopher Price, Bladesmith Link to comment Share on other sites More sharing options...
Doug Lester Posted October 20, 2009 Share Posted October 20, 2009 I appreciate the exchange of openions. We may be talking about the same thing from a different point of view. From what I understand from reading Verhoven is that tempering allows carbon to migrate out of the body centered crystal thus allowing the iron atoms to move closer together and decrease the stress on the atomic bonds. Both carbon migration and tempering is more dependent on temperature than time, which I think supports my point of view. Any metalurgists out there who might want toi chime in on this? Doug Lester HELP...I'm a twenty year old trapped in the body of an old man!!! Link to comment Share on other sites More sharing options...
B Finnigan Posted October 20, 2009 Share Posted October 20, 2009 My toaster oven is off by 125 deg (F) so I always use a thermometer. Everything I need to know I learned from the people trapped in my basement. I'm out of my mind but feel free to leave a message. Link to comment Share on other sites More sharing options...
Doug Lester Posted October 21, 2009 Share Posted October 21, 2009 Keep the thermometer on the same oven shelf as the knives and monitor the temp periodically. I was tempering some blades last night and I had to tweek the setting down by twenty degrees after about one hour. After that the oven held an even temperature for the rest of the evening. Doug Lester HELP...I'm a twenty year old trapped in the body of an old man!!! Link to comment Share on other sites More sharing options...
Brian Vanspeybroeck Posted October 21, 2009 Share Posted October 21, 2009 (edited) Edge quench and temper is OK if you want...Thermometers. Accurate temp measurement and control is very important. I use Brownells thermometers and they are very accurate for a $40 thermometer. http://www.brownells.com/.aspx/pid=1213/Product/HEAT_TREAT_THERMOMETER I use a Roaster Oven filled 3/4 full with low temp salt (You could probably use a higher temp deep fryer type oil to save $) along with the thermometer for tempering/martempering. The combination of the covered roaster oven and the added thermal mass of all that salt/oil creates a very stable low temp pot. Mine will hold 475f for at least 12 hours (in still air) with less than 5 degrees of temperature variation in that 12 hour period. http://www.google.com/products/catalog?hl=en&source=hp&q=Roaster+ovens&um=1&ie=UTF-8&cid=15152479783610457932&ei=dHvfSt7NB5XkMOuGifcN&sa=X&oi=product_catalog_result&ct=result&resnum=2&ved=0CBsQ8wIwAQ#ps-sellers At $50 for the oven and another $40 for the thermometer and a few $ for oil you can have a bang up low temp quench/tempering tank for around $100. As already stated the knob on the oven means nothing...mine is off by almost 100 degrees. But once you set it to the thermometer and let it stabilize it holds that temp. very accurately for more than long enough to temper or austemeper/marquench with tremendous accuracy. I'd guess you could fill the pot with gravel or glass beads or sand to get thermal mass for plain tempering and beat the toaster oven to death for accurate temp hold for cheaper still but I have never tried this. Edited October 21, 2009 by Brian Vanspeybroeck "Imagination is more important than knowledge" - Albert Einstein "The innovator is not an opponent of the old. He is a proponent of the new." - Lyle E. Schaller http://home.mchsi.com/~hermits/BrianRVanSp..._Edged_Art.html Link to comment Share on other sites More sharing options...
Doug Lester Posted October 22, 2009 Share Posted October 22, 2009 (edited) I use sand for thermal mass and it works quite well. Brian, thanks for the idea for a low temperature salt pot. What is the approximate dementions of the interior of that roaster? Doug Lester Edited October 22, 2009 by Doug Lester HELP...I'm a twenty year old trapped in the body of an old man!!! Link to comment Share on other sites More sharing options...
Brian Vanspeybroeck Posted October 22, 2009 Share Posted October 22, 2009 It's like 10" wide X 10" deep and long enough to get an 18" long blade in corner to corner...so probably 16" long. Approximately. You can spot these ovens all over the place at K-mart or any Walmart....anywhere that has kitchen stuff. I have a variable temperature 750 watt single burner electic hot plate that will do the same tricks with a stainless pasta pot on top full up with salt as well. These cheap little burners work great and while the knob is *WaY* off on temperature (use the good thermometer) they will hold a set temp very accurately once they have established a uniform temperature in a large pot. I used to hot rod fry pan controllers to get then to run up to 600f but find that a lot of the newer ones will run salt up to 600f out of the box. They run quite a bit hotter than the dial indicates. I think max temp. on the roaster oven I have is about 500f but I seldom need more heat than this unless I'm making something really weird. Which hasn't happened in a while. "Imagination is more important than knowledge" - Albert Einstein "The innovator is not an opponent of the old. He is a proponent of the new." - Lyle E. Schaller http://home.mchsi.com/~hermits/BrianRVanSp..._Edged_Art.html Link to comment Share on other sites More sharing options...
Doug Lester Posted October 22, 2009 Share Posted October 22, 2009 Brian, after I read your post last night I went to Amazon an eyeballed a roaster that was 24" long. I'm going to have to do a little more reasearch on this but this could be a good answere to a low temperature salt pot for austempering and martempering blades. Doug Lester HELP...I'm a twenty year old trapped in the body of an old man!!! Link to comment Share on other sites More sharing options...
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