HT Oven. Quick and Janky. A Plea for Help.

[Entropy762]

So in the new knife makers section I showed a blade I made out of O1. It was "heated treated" in my little two brick forge and tempered in a toaster oven. The Knife Dog LRB suggested I need to do more research on the heat treatment of O1. So taking the advice from LRB it seems I need to give O1 a soak time to get the best results out of the steel. Well the two brick forge isn't going to work. I had all the stuff to cobble together an HT oven. I know that using the pottery kiln may be less than ideal since it opens from the top. It may work for now. So the manual for the PID is giving me grief. The PID is an Auber SYL 2352 with the ramp, fuzzy logic, bells and whistles, ect. So my plea for help is how do I program this thing? I know this is a general question. Any help would be greatly appreciated.


Thanks,

Jake

 

[timgunn]

I've not used the Auber controller, but a quick scan through the manual suggests it should be good to go as a basic controller on the default settings, assuming you are using a type K thermocouple.

http://www.auberins.com/images/Manual/SYL-2352_manual.pdf

Control will probably be less-than-perfect on the default P, I & D values, but the Autotune will sort that.

I always run up to maximum anticipated temperature and let it cool overnight before running the autotune. This establishes an Oxide layer on the thermocouple and means the Autotune gets run with things the way they will be in actual use. I run the Autotune at the LOWEST temperature I will ever want to run at. This usually means a low tempering temperature. If you choose a high temperature for Autotune, my experience is that there will be massive overshoot at low temperature, whereas tuning at low temperature just gives slightly slower approach to setpoint at high temperature.

The ramp and soak programming is best worked through with the manual and equipment in front of you. As I have not used an Auber, I can't help on that. I've used many other controllers and the best advice I can offer is don't expect it to be a 5-minute job the first time. Strong coffee helps.

 

[LRB]

Jake, with basically simple equipment as you have, it may be best for now to just use a simple steel until you are able to, or decide to go to higher tech equipment. 1080, 1084 steel makes fine blades, and are much easier to heat treat. Little to no soaking is required, and with practice, you can judge temp pretty close by color. Common table salt, the salt marked plain, or sea salt/Kosher salt, melts at 1474°. An ideal temp for quenching most carbon blade steels. Choose an area in your shop, or where ever, a place that will have about the same low light most often, then melt salt on a piece of scrap steel. When it melts, take a mental note of the steel color. Practice until you think you are comfortable with judging that color, then go for it. I would suggest that you stay away from 1095 steel though. It has it's own set of problems for beginners, but those 10XX steels below 1095, and above 1070 are very much OK.

 

[scott.livesey]

with whatever you using to heat treat you need to know the temperature. go to Ebay or similar site, get a basic high temperature thermometer and a K type thermocouple. what i bought was https://www.amazon.com/gp/product/B00FFYEPVQ/ref=oh_aui_bia_detailpage_o06_s00?ie=UTF8&psc=1 and https://www.mcmaster.com/#thermocouples/=17i9zj4 in 14 gauge. the other part would be using a piece of steel tube(square or round) as a muffle. put tube in middle of furnace, put thermocouple in tube. tube protects the blade from the flame, the temperature inside the tube changes temperature slowly. keeping the temp +/- 10 degrees should not be that hard.