Table Top Kiln for Heat Treating Simple Steels?

P

PredHunter

Joined
Dec 2, 2013
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Hello,
I have been browsing my local CL adds lately looking for a suitable heat treat oven or kiln. Today as I was browsing and came across this Paragon table top kiln for only $70 and am thinking about picking it up for heat treating steels that are simpler to heat treat such as 1084 and O1. Would this be at all suitable (perhaps with a temp control added)? Or is it a waste of time and money?
Thanks for any advice
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It is a small jewelry kiln. It will work for small carbon steel blades. Add a simple controller and it will do for a starter kiln. The price is good.
 
I have been using a similar kiln for the last 3 years. works fine for blades with total length 11" or less. it gets hot enough for all basic hi carbon steels such as 1084, 80CrV2, O1, O7, or 52100.
 
Awesome, thank you all so much for your help. I am going to try my best to pick it up.
Thanks again
 
Contact paragon and see if they have a controller that will work with that model. Then you don't have to modify anything...
 
If it was me i would gut the controll box and rebuild it. Get a simple pid and 2 SSR's as well as a thermal couple. I would bet doing this would be cheaper then anything the manufacture has as a replacement.
 
For simple steels, pretty much any PID controller that will accept the thermocouple type and range you intend to use will work (most likely a Type K with a 0-2300+ degF range). The output needs to be compatible with whatever you are going to use to switch the power current.

Old-school would be a controller with a relay output to switch a contactor (effectively a big relay) which in turn switches the power to the elements. On the upside, a single contactor can switch both hots. On the downside, it's noisy and does not like short cycle times. The SYL 2342 and SYL 2362 linked from post #6 will both handle this.

More up-to-date practice is to use Solid State Relays (SSRs) to switch the power to the elements. Downside is that you need two of them for 220V in the USA: one for each hot. Upside is that they are silent and can be used with shorter cycle times. The controller for SSRs will need to have a pulsed DC output to trigger them. The SYL 2352 and SYL 2362 both have pulsed DC outputs.

The most important thing with the controller is support. I'd recommend pretty much anything from Omega or AutomationDirect because I've used stuff from both and they have very knowledgable, and patient, telephone support. I am in the UK and have not used Auber, but understand they have similarly good support in the USA.

The really cheap Chinese PID controllers from Ebay can be very good, but I'd not recommend them unless you are already familiar with PID controllers in general. Support is usually non-existent from the supplier and the manuals are generally poor or worse.

Whatever you are thinking of buying, download the manual first and bookmark the link, read it carefully until you understand most of it (strong coffee helps).

If there is no online manual, do not buy it. With a link to the manual, a cry for help on a forum is quite likely to get a helpful response from someone who understands controllers generally, but has not used your particular model. Without a link to the manual, you are on your own.

If you are intending to use Stainless Steels in the future, a ramp/soak controller may be a good idea, though all of the industrial ramp/soak PID controllers that I have used have been horrible things to program for the ramp/soak profiles. Do not expect to get the ease of use from one of these that you get from a dedicated kiln ramp/soak controller; the ones on Paragons, Evenheats, etc, are designed with ease-of-use by a non-technical operator as the main priority.

If you use a non-ramp/soak controller, leaving an extra couple inches on the wiring is a good idea. Different controllers have different terminal layouts and the extra length allows future upgrade without having to extend the wires. The most common controller size is 48 x 48mm and is usually the cheapest choice, though 96 x 96mm is nice if you have middle-aged eyes and need to read it across the shop.
 
I also say get a simple pid, I have messed with both the simple and the ramp soak and would never go back to one. That's not saying I don't like those features but thy are difacult in the normal pids. If it was me I would get this, I love there controllers.

https://www.auberinc.com/index.php?main_page=product_info&cPath=1&products_id=3

Then 2 of these, thy are 25amps so look at your oven and make sure it uses less then that.
https://www.auberinc.com/index.php?main_page=product_info&cPath=2_30&products_id=9

Then mount each SSR to this heat sink.
https://www.auberinc.com/index.php?main_page=product_info&cPath=2_48&products_id=45

After that you just need a thermal couple and some wire and a plug. That's easy to find on eBay for under $20 with free shipping.
 
get a high temperature thermocouple and separate display. position the thermocouple so it almost touches the center of the blade. I found using the power dial on the kiln I could keep the temperature at 1475F without any trouble.
 
Wow, thank you all so much for the wealth of info, I really appreciate it. I apologize for the late response. I will likely go with the PID and 2 SSR combo that JTKnives suggested. Would this combo be very difficult to wire up with limited electrical experience?
Thanks again for all the help
 
first thing is buy a thermocouple and display. then you can tell what is happening inside the kiln. see how much control the will stabilize the temperature. you should be able to keep the heat in the 1475-1500 range. most blades will be in the furnace for less than 15 minutes, so this is a constant monitor situation. that you have to adjust the power control a little is no big deal.
to wire the controller at bare minimum you need power, thermocouple inputs, and relay outputs. to operate the kiln shown, you need a controller and 1 SSR. most controllers have an output of 5 volts dc, so you need an SSR that uses 5 volts to turn on and off. the nightmare will be programming the controller, no two companies do it alike, they don't even use common terms.
 
The pid i I linked is a small version of the one I have used for years and it's very simple to use. It has a 12v DC out put for SSR control. The SSR's have a 3-32v DC trigger voltage so thy are not picky at all. Is your oven 110v or 220v. If 110v you can just use 1 SSR but 220v requires 2 SSR's. these things are super simple to program. You turn on the power and push the up button. You will see the last digit flashing. You push the up button agian to change it to what ever number you want. If your setting 1475 then set it to 5 and then push the left button to move to the next digit which is 7. Then left agian and set that to 4 and then left one last time and set that to a 1. That's it, takes just a few seconds. It will take over and control your oven and you do t have to baby sit it. I have one connected to my quench tank. The pid is also connected to a wifi switch so I can turn it on or off any where in the world I have internet or cell service.
 
The wiring is super simple. You can make it as complicated or simple as you want. This is my control for my quench tank. Befor it was on the quench tank it controlled my forge. But now that I have an oven I don't use the forge any more for heat treating. Now I'm not saying to do it like this as it's not exzactly "safe" becaus nothing is enclosed and you could shock your self if you touched a termanial. I'm just using it as an exzample.

Your power comes in and the hot leg goes through a switch so it's switched. Then the hot and neutral need to split so you have 2 hits and 2 neutrals. One hot and one neutral goes to the power in on the pid. This powers the pid so when you switch the switch on the pid comes on. You then run the other hot leg to one side of the SSR that says AC. Now one side of your elements will connect to the other AC terminal on the SSR. The other elament wire will come back and wire up to the neutral wire you split off. Now there will be a DC+ & DC- output on the back of the pid. Run a wire from those to the DC+ and DC- on the SSR. That's your trigger signal. The pid turns on and sends a 12v DC singable out those wires to the SSR which turns it on. A SSR has 4 connections AC1 and AC2 and DC+ and DC-. Your elament power goes through the AC connections just like a light switch except instead of your hand switching it on or off it it's a DC voltage that turns it on and off. the last step is to wire your thermal couple. It should say TC on the back of the pid. There is a + & - and remember Red is allways -. If your temp goes down when heating then the TC is backwards and you need to flip something around. Your TC wire will have a yellow and red wire. Red goes to the negative and yellow goes to the positive. The thermal couple it's self will have (should have) one leg marked red. That leg gets connected to the red wire and the yellow wire gets connected to the other leg. But like I said if the temp reads backwards and goes down the swap the wires on the thermal couple legs.

It's actually quite simple and easy once you start going. If you need any help I will be glad to assist. Here is my hobo set up for my quench tank.
Photo%20Nov%2015%2C%202%2027%2035%20PM.jpg
 
If you want I can do a short video and show you my system and how it's all wired up. That will be a lot simpler then my explanation above lol. Also show you how easy it is to program.
 
JTknives said:
If you want I can do a short video and show you my system and how it's all wired up. That will be a lot simpler then my explanation above lol. Also show you how easy it is to program.
Click to expand...
Wow thank you so much for all the help JTknives. I really appreciate you taking the time to share your knowledge and help me out. I am going to do what you said and purchase the components you linked. Hopefully, I will be able to wire and program it with the info you have already generously taken the time to provide me. The kiln is 110v so I will just purchase 1 SSR.
Once again, I apologize for the delayed response.
 
I will try and shoot a quick one tomarow befor work.
 
Ok i recorded this video rather quickly before work. hope it answers any questions you might have. if not let me know and i will try and answer them. the recording stopped in the middle of me saying something, don't worry its not important.
 
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