DIY sword tempering oven

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Stacy E. Apelt - Bladesmith said:
Any tube, ,round or or square, will work. It is just a shell to wrap the insulation around. Think of this project as a long thin toaster oven. Sheetmetal would be fine. Use two elements if needed to get the desired length. You could even put them on separate controllers to keep the oven evenly heated.
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Ok I'm on my way to get some tile/kaowool/high temp gasket putty(glue/caulk etc). I'd rather not have to buy a controller since you are helping me out with one.

Stacy you said something earlier that I kinda missed. I think I'd rather follow some plans on youtube to build a basic grinder for these tasks rather than try and hand grind metal. what horsepower motor would you recommend for sword grinding?

Whats the longest 110 heat element you've seen out there? I dont want to do as many as natlek. Surely 2 long ones would do the task? most of the long ones i see for elements are 220 volts.
 
McMaster-Carr has versa-mount heating elements up to 65" long. No idea how well they will work for what you are trying to do.
 
A basic grinder with a 1HP 3Phase motor and a VFD will work just fine and run off 15VAC. I like an 1800RPM motor, but some folks like the 3600 RPM type.
This guy is a good source and if you get him to do the extras it comes plug-and-play.
https://www.ebay.com/itm/KB-Electro...var=512829369089&_trksid=p2060353.m1438.l2649

Any two 20"-24" long elements will work. I'll send you two controllers. IIRC, they will control a 500 watt load. As long as the elements are less than 500 watts each, you should be fine. There are ways to use them to control larger loads if needed.

I would hold off getting parts and stuff and first draw up your plans and post them here. Post all materials and such you plan on using. There may be a better way, or something you haven't considered (or don't know about).
 
Tony Park said:
Ok I'm on my way to get some tile/kaowool/high temp gasket putty(glue/caulk etc). I'd rather not have to buy a controller since you are helping me out with one.
Whats the longest 110 heat element you've seen out there? I dont want to do as many as natlek. Surely 2 long ones would do the task? most of the long ones i see for elements are 220 volts.
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Slow down my friend ...............It would be no easy to make it from ceramic tiles .Can you tell us dimension of oven you want to build ?
 
Natlek said:
Slow down my friend ...............It would be no easy to make it from ceramic tiles .Can you tell us dimension of oven you want to build ?
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Im confused. didnt you use ceramic tiles? THis is for making swords. Inside working length should be 48 inches.
 
Tony Park said:
Im confused. didnt you use ceramic tiles? THis is for making swords. Inside working length should be 48 inches.
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Ceramic tile are ok , but I give up for using them in my long tempering oven / 35 inch/ because it will not be easy to hold them together in that length without some angle iron frame ........Even in my small one what now really hold them together is insulation .Other thing is that tile are some kind of heat sinker , which is good , but in this size oven you will use lot of tile and you will need more power / watts .48 inch long oven , Stacy is right heat elements just on one end would not work .......in over 1.2 meter long chamber .
Can you find some steel pipe ? Maybe two or three old fire extinguisher and if you have welder you can joint them in one tube ?
One more thing , there are different fan type for convection ovens .The one i used in mine / in my finished oven/ is slow and almost noiseless and work perfectly in that size of chamber .But it will not work in new one i will build soon .I mean it will not push air to the other end of the chamber ,simple have not that power .I ordered spare one for my kitchen oven , which is more powerful .We need good circulation of air inside , without that it will be like toaster oven ..........
 
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For a tempering oven, a section of ductwork or flue pipe will be fine.

Ohhh .. I have three 30"pieces of tri-wall stove chimney sitting out by the smithy. I can add a heating element and make each into a tempering oven with its own controller. They can be connected by merely locking them together as needed for a longer oven. I can make ends from 1" Ins-board that will lock on them.
 
All this rigormoral is why I stepped away from finicky overly complicated to build electric ovens of any sort
 
ok so after some frustration with the ceramic tile thing not going to be of use, I realized, I can build a pizza oven with all that.

so, after scouring the internet and finding photos and watching as many videos on the subject as I can find.....

I've decided that I'm going to do a few things differently.

Apparently, gravity warping long blades is kind of an issue.

I've decided to build it vertically. it's just for swords.

Basically it's a tube with kaowool inside.

Like this: https://www.oneida-air.com/10-inch-...DW83ZnecB6jebjdBZZqfrIlB_zQod2LkaAjepEALw_wcB

What i can't figure out is this:

I probably have to use kanthal wire wrapped around a stick to make my own springs. I saw a video where some kid in England used 18 gauge. So say i make 2 springs ok kanthal that are 4ft long.

How do they hook up to the PID controller and will 2 springs that long and that gauge be too much for typical home power?

Relatedly, i assume one end of the spring goes to the controller. What does the other end go to? My hope was to hang the springs from the top and then feed the end down through the bottom to the controller.
 
Tony Park said:
ok so after some frustration with the ceramic tile thing not going to be of use, I realized, I can build a pizza oven with all that.

so, after scouring the internet and finding photos and watching as many videos on the subject as I can find.....

I've decided that I'm going to do a few things differently.

Apparently, gravity warping long blades is kind of an issue.

I've decided to build it vertically. it's just for swords.

Basically it's a tube with kaowool inside.

Like this: https://www.oneida-air.com/10-inch-...DW83ZnecB6jebjdBZZqfrIlB_zQod2LkaAjepEALw_wcB

What i can't figure out is this:

I probably have to use kanthal wire wrapped around a stick to make my own springs. I saw a video where some kid in England used 18 gauge. So say i make 2 springs ok kanthal that are 4ft long.

How do they hook up to the PID controller and will 2 springs that long and that gauge be too much for typical home power?

Relatedly, i assume one end of the spring goes to the controller. What does the other end go to? My hope was to hang the springs from the top and then feed the end down through the bottom to the controller.
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Tony my friend . . . . . stop . Things not going like that ........so you make two spring 4 ft . long from Kanthal .Now what ? How you will install them inside steel pipe , they are under 110 voltage, they must not contact the steel pipe. Other thing which is very important is how much Watts , Amps they are .About Pid , it is not that simple , you need solid state relay of adequate power to handle elements on/off .SSR is what switch elements on/off not PID , Pid just give order to SSR ......
Simple way to build this oven is as we already talk about . Forget spiral Kanthal wire ....would be expensive to build that way .And you really need to use FAN .Without fan you will never get even temperature in that size oven .
 
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If you can t find long enough elements you can use four .....like this . but even like that would be little problematic to install elements .You need to isolate ends/power contact from metal tube
fxwZ4Fj.png
 
Natlek said:
Tony my friend . . . . . stop . Things not going like that ........so you make two spring 4 ft . long from Kanthal .Now what ? How you will install them inside steel pipe , they are under 110 voltage, they must not contact the steel pipe. Other thing which is very important is how much Watts , Amps they are .About Pid , it is not that simple , you need solid state relay of adequate power to handle elements on/off .SSR is what switch elements on/off not PID , Pid just give order to SSR ......
Simple way to build this oven is as we already talk about . Forget spiral Kanthal wire ....would be expensive to build that way .And you really need to use FAN .Without fan you will never get even temperature in that size oven .
Click to expand...

I was planning to coat the inside of pipe with kaowool.

Yes I will need an ssr too. Can you think of anything else?

I dont mind using a fan. But its best to have elements running the whole length
 
Tony Park said:
What i can't figure out is this:

I probably have to use kanthal wire wrapped around a stick to make my own springs. I saw a video where some kid in England used 18 gauge. So say i make 2 springs ok kanthal that are 4ft long.

How do they hook up to the PID controller and will 2 springs that long and that gauge be too much for typical home power?

Relatedly, i assume one end of the spring goes to the controller. What does the other end go to? My hope was to hang the springs from the top and then feed the end down through the bottom to the controller.
Click to expand...
There isn't really enough information to calculate the coil resistance and power. The size of the mandrel matters and you have to stretch the coil after you wind it, so the final length is really not that important. I recommend you start with a coil calculator. Dan Comeau has a spreadsheet on his website, look here to start.

You should not connect the coil directly to the SSR, use a heat proof terminal of some sort and run copper wire of appropriate gauge from the SSR to that. It might be a good idea to double over the ends of your coils and twist them to lower the resistance for the last few inches that go through the wall.

I would recommend to install some safety cut-off switch that automatically disconnects your heating elements when the door is open, I am not sure an exposed Kanthal coil is the way to go here for long term durability as you're bound to hit it with a sword sooner or later. A solid element like Natlek suggests might last longer, but either way make sure you don't get electrocuted.
 
Ok, so based on input from oven builders at another forum,

I think i've settled on this element https://www.mcmaster.com/3540K43/

Stacy sent me a few emails offline. I'm hoping to document the build and create an idiot proof parts list and readable diagrams with actual photos. I've ordered the pipe/insulation so thats coming too.

Tony
 
You need to slow down a bit and get this figured out before you start buying stuff.

Edited. I see that the element will work in air.
It comes in many lengths, so you can get one the size needed. It does draw a good bit of current. You would need a PID, TC, and an SSR to control it. I have those for you.

You might want a larger tube for this build. HD has duct in 4" through 10" in 5" lengths.
The links I sent you were for examples of insulation that would work for te inside and outside of the tube.
 
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I look forward to seeing what you come up with. Are you mounting the element on the top or bottom? The element has a minimum bend radius of about 1". I'd probably keep it straight and mount it front and back, possibly with a few stand-offs to keep it off the bottom along its length. I've been pretty happy with my PID. SSR and thermocouple from Auberins, but there are probably cheaper options.
 
Stacy E. Apelt - Bladesmith said:
You need to slow down a bit and get this figured out before you start buying stuff.

Edited. I see that the element will work in air.
It comes in many lengths, so you can get one the size needed. It does draw a good bit of current. You would need a PID, TC, and an SSR to control it. I have those for you.

You might want a larger tube for this build. HD has duct in 4" through 10" in 5" lengths.
The links I sent you were for examples of insulation that would work for te inside and outside of the tube.
Click to expand...

Do you think that one thermocouple would be enough for 4 foot long oven even if element is that long ? I think that without fan he will never get even temperature in that size oven.
I borrowed yesterday from store same type of fan as i used in my finished tempering oven .I make cardboard extension for my stainless tube / 80 cm. long / and i try that fan again...........no way it can reach other end ,even at 80 centimeters in length it doesn't work, that's why I ordered another one. Simple lack of power , air circulated but like on picture .....can t reach other end .I don t know if one I ordered /more powerful/ will circulate air in 4 foot long tube .
GIBUK3A.png
 
I think he needs two 24" elements each with its own controller. That way you won't have any significant temperature variation from one end to the other.
I don't think a fan will work in such a long tunnel oven.
 
Stacy E. Apelt - Bladesmith said:
You need to slow down a bit and get this figured out before you start buying stuff.

Edited. I see that the element will work in air.
It comes in many lengths, so you can get one the size needed. It does draw a good bit of current. You would need a PID, TC, and an SSR to control it. I have those for you.

You might want a larger tube for this build. HD has duct in 4" through 10" in 5" lengths.
The links I sent you were for examples of insulation that would work for te inside and outside of the tube.
Click to expand...


Yeah i believed you so I bought stuff. :) Well the tube anyways. I'm not sure you have PID/controller/tc that will work with this element. I like it because its one less thing to wire up than 2 elements. Simple for the noob.

I also got tremendous help from a specific forum on ovens.

What I found out was I could use this element. Bend it at the ends the correct length and run the ends out of the tube into junction boxes, one of which will also house a controller.

Basically, the fact that im a renter kind of makes it impossible for me to over build this so I'm just going to buy a 5 foot length of duct in 8 inch diameter. put 2 inches of kaowool on the inside and that other wool you recommended on the outside.

What makes the kaowool stick to the inside of the tube? Where can I get the best deal on kaowool and the outside wool? It seems like I want 2 inch thick kaowool, anything else I need to know about this?
 
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