Heat Treat Oven...

For the base, check out "kiln furniture". They are small shelves and supports used by potters when backing items into a kiln. Kiln shelves are part of that. They are ceramic, come in various shapes, can be cut, and are relatively cheap. You might check if you have a ceramic supply house nearby, I have one less than 2 miles from me and didn't even know about it until I started looking at building a kiln.
 
Thanks Dan and all for the links.

So far, I've gone with the following items:

http://www.lightobject.com/JLD612-Dual-Display-PID-Temperature-Controller-P43.aspx
http://www.lightobject.com/High-Temperature-2370F1300C-10ft-Ceramic-K-type-Thermocouple-P411.aspx
http://www.lightobject.com/40A-Solid-State-Relay-SSR-DC-In-AC-Out-P62.aspx
http://www.lightobject.com/Heat-sink-for-40A-SSR-P590.aspx

And I ordered a boatload of coiled Kanthal A1 wire rated for 240V, 3000W. It was a much larger quantity than needed but was only 20 bucks on eBay.

Ray
 
A brief update on the heat-treating oven...

The necessary ingredients have arrived. The controller came with no instructions but, were found online. The manual is not translated well and takes a bit of patience to comprehend. I've got it figured out now. Since folks around here would probably get ticked if I burned the house down, I decided to set it up at the kitchen table and experiment with setting it at sane temps and manipulating the sensor with cups of warm and cold water while observing the electrical outputs with a voltmeter. Indeed, it works -and seemingly well.

You'll have to take my word for it but, it shows the correct temperature and the main relay and hi/low alarm relays all trigger in accordance to the programmable upper/lower boundaries.

I'll probably start making the enclosure in a couple weeks but, have some paying jobs in the shop to finish first.

Here's some eye-candy:

Test Setup.JPG
 
Thanks Dan and all for the links.

So far, I've gone with the following items:

http://www.lightobject.com/JLD612-Dual-Display-PID-Temperature-Controller-P43.aspx
http://www.lightobject.com/High-Temperature-2370F1300C-10ft-Ceramic-K-type-Thermocouple-P411.aspx
http://www.lightobject.com/40A-Solid-State-Relay-SSR-DC-In-AC-Out-P62.aspx
http://www.lightobject.com/Heat-sink-for-40A-SSR-P590.aspx

And I ordered a boatload of coiled Kanthal A1 wire rated for 240V, 3000W. It was a much larger quantity than needed but was only 20 bucks on eBay.

Ray

Wow, pretty amazing!!! Just found your thread and wanted to read what you had done and see your progress. Funny thing is I just ordered the exact same four components from the same ebay vender... the EXACT same components. Our research must have been pretty similar. Do you have an update for us???
God Bless, Frank.
 
I have some similar aspirations, but I will be trying a controlled atmosphere furnace. I happened on a T-30 IR vac pump that should do the job if I want a vacuum, and I can get whatever gas I need locally. Need to work out the quench method though.
 
Sorry Frank, this project was delayed... My brother in law died suddenly on Christmas day, my son ruptured a disk in his back a few weeks later and my Mother in Law passed away just over a week ago. All my personal projects are completely out of sorts. My plan was to do heat treating in the garage/shop over the winter. I'll probably build it sometime in the next month or so but don't know how much I'll use it in the summer months. The shop gets pretty warm....

Ray
 
Sorry to hear about your losses. I'll send up some prayers for you and your family.
God Bless, Frank.
 
Ray,
You sure did have a run of luck. Hope the best for you and yours and I will be watching for the completion of this when you get back around to it too. I am really curious how it is going to work out and what temps it is going to successfully maintain. What do you plan to block the door with? or do you plan to have a honey hole type of thing you can put items in and remove them along the way for forging or working on a horse or anvil? I'll be watching for the completion when you get the time and things calm down a bit in life.

Bob
 
Well Bob, between you, me and the rest of the Internet, I'm kinda curious about how the furnace will turn-out myself...
:panic:

Seriously though, I have some ideas and will model it after this one: http://www.knightsfurnace.com/heat-...lypage=flypage.tpl&product_id=4&category_id=1


My intended changes are to use the insa-wool instead of the fire brick. If you recall, I got some coaching from a guy who designs industrial kilns and ovens. He steered me in the direction of insa-wool because it insulates better and because it is so lightweight, does not absorb energy (and thus heats-up 3x faster than brick units). He strongly recommends this for part-time use equipment. The downside is that it only lasts 7-10 years under use. I purchased enough to make 3 units and will put the rest in storage. I'll just re-insulate if/when the time comes. I'm OK with this tradeff and see it as win-win -and I sure as heck don't need another 300lb item in my shop.

Like Tony mentioned, I've been pondering atmosphere control but am kicking-around ideas. I really don't want to mess around with SS foil bags and doing oxygen burns. My latest thinking is flooding w/ CO2 or AR. -Wouldn't take much but might possibly need a trickle-flow. I think I can dredge-up some spectrometers to measure air infiltration -or maybe not and just take a guess at a decent trickle rate.

For sure, vacuum units would be the cat's meow but, the vessel materials cost will shoot-up considerably. CO2 and AR are cheap and we're talking about using as much as I would in a couple hours with the TIG torch...

Anyhow, you can hold my feet to the fire (pun intended) to see if it turns-out this way.


Ray



Ray,
You sure did have a run of luck. Hope the best for you and yours and I will be watching for the completion of this when you get back around to it too. I am really curious how it is going to work out and what temps it is going to successfully maintain. What do you plan to block the door with? or do you plan to have a honey hole type of thing you can put items in and remove them along the way for forging or working on a horse or anvil? I'll be watching for the completion when you get the time and things calm down a bit in life.

Bob
 
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