Elemental Metal Creations Posted July 17, 2017 Share Posted July 17, 2017 I have a couple of knife blades ready to harden and temper. I have an old deep fryer that I plan to use to warm peanut oil for hardening. I do not have a toaster oven yet and my wife does not want me to use her oven. I was thinking of hardening the blades and then turning the deep fryer up to 400 deg. and after the oil reaches temp. putting the blades back in for a couple of tempering cycles. Has anyone done this, or does it sound reasonable? Thanks in advance. Quote Link to comment Share on other sites More sharing options...
ThomasPowers Posted July 17, 2017 Share Posted July 17, 2017 Absolutely wonderful or absolutely terrible depending on information you didn't provide: what is the alloy you are using? 400 degF may be too hot or too cold depending on the alloy and intended use, (razors generally temper cooler and machetes may even go hotter for example) Quote Link to comment Share on other sites More sharing options...
Elemental Metal Creations Posted July 17, 2017 Author Share Posted July 17, 2017 Thomas, it is unknown steel from an old circular sawmill blade, It seems to temper well at 400. I have done it in the oven at work before but it is not an option this time. I was just wondering if the concept / my thinking was sound. Quote Link to comment Share on other sites More sharing options...
ThomasPowers Posted July 17, 2017 Share Posted July 17, 2017 Sure a lot of stuff is heat treated commercially with immersion (using various salts for the high temp before quenching and different ones for low temp) You've already checked that 400 degF was appropriate---I stand up and applaud you! Make sure that the oil is a uniform temp and do not touch the blade to the side of the container and BE READY FOR OIL FIRES due to accidents (Don't do this inside your house!!!!!!!) Quote Link to comment Share on other sites More sharing options...
Hotshoein4 (Mark) Posted July 17, 2017 Share Posted July 17, 2017 I'd go buy a cheap toaster oven. Maybe even Craigslist or garage sale. Seems to me it would be a safer route. I think trying to maintain the proper oil temp is going to prove to be a challenge. Quote Link to comment Share on other sites More sharing options...
Elemental Metal Creations Posted July 18, 2017 Author Share Posted July 18, 2017 Hotshoe, I have been looking for a used toster oven for a couple of months now. When I didn't want one I saw them every where, now that I want one the few that I have found had near new prices on them. Quote Link to comment Share on other sites More sharing options...
Buzzkill Posted July 18, 2017 Share Posted July 18, 2017 19 hours ago, Hotshoein4 said: I think trying to maintain the proper oil temp is going to prove to be a challenge. Maybe, but with the thermal mass of the oil it will hold temperature a lot better. Toaster ovens tend to bleed heat badly, cycle frequently, and are therefore much less likely to provide a steady temperature. Don't get me wrong. I use one for tempering, but if the temperature on the fryer can be reasonably controlled and maintained I think it could provide better results. Quote Link to comment Share on other sites More sharing options...
Frosty Posted July 18, 2017 Share Posted July 18, 2017 A reliable way to moderate the temperature cycles in a toaster oven is to place the piece you're tempering between heat sinks. A couple pieces of say 1/2" mild that is wider and longer than the piece. Were I doing a lot of blades of a general profile I'd make a pottery mold and have it bisque fired. Sandwiched between a couple pieces of stoneware an inch or so thick and it won't make a lot of difference how often or fast the toaster oven cycles. I've done similar annealing thin stock by encasing it between heated steel stock before I do my Kaowool wrap and bury in Perlite slow cool. The extra thermal mass extends cooling time in the anneal just as it will in a tempering oven. Frosty The Lucky. Quote Link to comment Share on other sites More sharing options...
Buzzkill Posted July 18, 2017 Share Posted July 18, 2017 Thanks for the tips. It was kind of a head-slapping "duh" moment for me, but I hadn't thought of that. Quote Link to comment Share on other sites More sharing options...
Elemental Metal Creations Posted July 20, 2017 Author Share Posted July 20, 2017 Thomas, thanks for the applause, I try to do my home work even though it doesn't always show. Frosty, thanks for the info. I will keep it in mind for when I find a toster oven. Quote Link to comment Share on other sites More sharing options...
Latticino Posted July 20, 2017 Share Posted July 20, 2017 We tempered our swords in heated canola oil during a workshop at Peter's Valley. Worked extremely well as far as we could tell. Temperature adjustment came from use of an immersion thermocouple and adjustment of the output and placement of an external NA propane burner. Quote Link to comment Share on other sites More sharing options...
Frosty Posted July 20, 2017 Share Posted July 20, 2017 Thinking about it further, sand would work as well and be easy to cover with and not particularly dangerous. I see toaster ovens at yard, garage, etc. sales all the time, almost as common as blow driers.The toaster oven I bought for the shop is newer and nicer than the one in the house, it cost me $5.00 but I bundled a couple chisels and a hammer head with it. That was a local church rummage sale. Frosty The Lucky. Quote Link to comment Share on other sites More sharing options...
lanternnate Posted July 20, 2017 Share Posted July 20, 2017 Plunk a firebrick in the toaster oven and preheat it. The brick is going to absorb the heat and regulate the fluctuations. Simple but effective. On the original topic, I'd much rather dedicate a toaster oven to tempering than a deep fryer. Toaster ovens are cheap, even a new one, and it'll just overall be a cleaner endeavor. Quote Link to comment Share on other sites More sharing options...
Elemental Metal Creations Posted July 23, 2017 Author Share Posted July 23, 2017 Well, my deep fryer fried, I don't understand why, it was only 10+ years old. I now have a double walled quench tank with a lid so I heated a rr spike in the forge, chucked it in the oil to warm it and hardened 2 blades. I had to use the wife's toaster oven to temper them. i was really looking forward to experimenting with tempering in the deep fryer. Quote Link to comment Share on other sites More sharing options...
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