Need a Kiln, Make a Kiln…

Cool beans...if you already have the tooling. Otherwise you're probably better off just buying an oven unless you think you want the challenge of building one.

I'd like to read the thoughts of people who've done this, the pros and cons. I have a box of fire bricks my father bought years ago but never used, just not sure if it's worth the trouble to build a second kiln.
 
I built my own heat treat oven very recently: https://www.bladeforums.com/threads/heat-treat-oven-thoughts.1991541/

I gotta close up some gaps in the bricks and stuff, but it was MUCH less expensive than buying my own 27"!! My chamber is 27" long x 7" wide x 6.5" tall. I used Jarod Todds method of the elements going over fused quartz tubes on the top of the oven and used most of RedBeard's wiring info/components. My element is a 3840 watt element in 12/13 AWG kanthal, so it should be very durable!

If you can weld up a frame and cut bricks and do some basic wiring, it's not too bad to do. The Coil over Tube construction is a little more complicated than the coil in wall construction, but once I got the coils stretched, bent and spaced straight, they fell into place nicely. That was the hard part; getting the coils in line with each other when I was bending them!
 
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The cost savings on building a kiln big enough for a sword is significant. the cost for an Evenheat is like 5kCAD (.$36USD) Im only into this $910.62 so far. Im sure I will need a couple more odds and ends so lets round it up to $1k. thats still a significant savings.
 
It works! (still need to put the last video together)

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I sincerely appreciate you guys who take the time to make these videos. I'm still on the fence as to build or just farm out HT but every time I see one built, I lean that way.
Thanks
 
I was nervous at the start, and although not as pretty (although I started painting it gold and black) I am quite happy how it turned out. I would only build as big as you need though. This does take a while to heat up to temp. Not as long as the pottery kiln, but still a good 3.5 hrs to get to 1600. Anyone know what an Evenheat of similar size takes to heat up? My wife’s Skutt kiln takes about 5 hrs.
 
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My 27" x7" x 6.5" takes 2 hr 40 min to get to 2000 on 240v. The bricks are 40% more dense than what k23 are supposed to be, so I think that is why.
 
Whats your wattage and cubic foot # inside the oven? You usually want 5000 watts/cubic foot. Are you using 240v or 110v? It's a big oven, but it's still pretty slow.
 
6000 watts. 240v. I did my calcs in this article Kiln Build. I was trying to stay within 30A circut, but I have a 50, so may swap out the elements. I have lots of 14g kanthal
 
Ok, I would try to bump up the elements a bit maybe or add a third element (ceiling?)? I didn't see pages 4 and 5 of the article before! LOL.

I am surprised that with 2, 3000 watt elements, it is taking that long? You aren't too far off on the 5000 watts/cu ft with 1.25 cu ft of interior volume? Another option is to reduce the chamber size down width and height wise, but if it's for swords, you may need that space! I was lucky enough to find a premade element that worked perfectly for my electrical needs, so I lucked out there!!
 
I suspect it might be the PID I chose. When I was reading (lots more) I found a few guys saying ITC 106VH was better for liquids. have to go back inside to look up what the suggestions were, but PID might be what is making it slow.
 
Look up the AutoTune info on the Inkbird. I picked up the same one until my Auber 2352P gets repaired from when I fried it. If you turn the auto tune off, it may go faster?
 
SolarStorm50 said:
I suspect it might be the PID I chose. When I was reading (lots more) I found a few guys saying ITC 106VH was better for liquids. have to go back inside to look up what the suggestions were, but PID might be what is making it slow.
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ITC106VH is the version with dc Voltage output (to drive an SSR) for "high" voltage (AC mains, 100-240VAC, as opposed to the 12-24VDC for the "low" voltage version). It doesn't know or care whether the process it's controlling is solid, liquid or gas.

From the instructions I can find online, there doesn't seem to be any way of putting the controller into manual and driving the output to 100%. It's something that can be done with every controller I've ever used, so I'd be quite surprized if it can't be done at all. If you have a manual that tells you how, do it. You should see the "Out" led indicator lit continuously and you should see the led, if there is one, on the SSR continuously lit. It should then heat as fast as possible, with the element power being the limiting factor. If the temperature rises faster than in auto, the controller has been limiting things. If heating is at the same rate as in auto, it hasn't.

If you can't put the controlller into manual, setting P to maximum, I to 1(one) and D to off, with the setpoint set to maximum, should get you continuous output until close to the setpoint.
 
Nice one OP.

I'm always impressed at the diversity of both skills and tools you guys have. It's impressive.
 
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One fellow a while back added a small 12VDC power supply and wired it with a switch marked "By-Pass" to the SSRs along with the PID wires. The line from the switch had a big red 12VDC lamp in it that he marked "BY-PASS".
He would turn on the PID and then flip the by-pass switch ON and the kiln would run at full power until he shut the by-pass switch OFF as it reached the desired temperature. It then ran on the PID.
 
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