Heat treat oven

[radkins]

Been trying to do some heat treating the last couple of days using fire brick and a large Propane heating torch but it is hard (closer to impossible) to precisely control the heat and is very wasteful of fuel. This has gotten me started on something new now and given me an idea for a new project if it is practical, an electric heat treat oven. I am not asking for a "how to" I just want to know if it is a practical undertaking and maybe an idea of what materials would be needed.

Is this practical or should I just look for a used one, there were some listed locally last year for around $400 used and supposedly in good shape but they don't have any listed right now.

[Mcgyver]

haven't done it, buy my sense is its very practical....there's several good examples on the web. I have the IFB's in stock waiting for it to percolate to the top of the list.

[Dale Lusby]

A pottery kiln might be a good compromise. They are usually found cheap and can get up to 2000°F. I would assume you could add accessories later for a better control of temp but in the meantime you could get some of the marking material that melts at a given temp to know when you reach correct temp. I also saw a website where someone built one with controls and all and it seemed to work out great. Might have to do some searches on google to find more.

[Evan]

Here are the threads about the one I built.

http://bbs.homeshopmachinist.net/showthread.php?t=40495

http://bbs.homeshopmachinist.net/showthread.php?t=40558

http://bbs.homeshopmachinist.net/showthread.php?t=40809

[Bob Ford]

Radkins,

I decided that I would just buy one. Too many other things that were more fun to do.
Jantz supply Evenheat. http://www.knifemaking.com/category_s/122.htm

The big selling point for me was the door opens sideways. No red hot door under your hands when getting into the furnace. Next good reason replacement parts are available.

Bob

[Tait]

+1 for the evenheat.

Also, a bunch of knifemakers have made home-built heat-treat ovens. I'd suggest searching around at bladeforums.com and knifedogs.com.

[rowbare]

You can get all you need to build a kiln at a well-equipped pottery supply shop. These guys are in Canada but it should give you a good idea of what you might expect to spend.

http://www.pshcanada.com/kilnbuild&repair.htm

http://www.pshcanada.com/kilnacc&repparts.htm

bob

[radkins]

Well I have been doing some serious searching today for plans and looking at some of what I have found I think I may just take Bob's advice and buy one. The small Everheat kiln is just about the size I would want but I had set my budget at $400 or maybe even $500 which would limit me to either used or building my own, looks like I may have to rethink my budget however. I did find two used ones at the same place I saw some last year but something I had not considered was these are industrial ovens and are 440V 3 phase and somewhat bigger than I wanted, they did however fall into the range I was willing to spend. I can afford the Everheat easily enough but it is really a question of will I use it enough to make the expense worthwhile? Being realistic I doubt I could justify the cost considering what my needs are but then sometimes it boils down to greed and not need so I will take a serious look at the small Everheat.


BTW, Even that oven project is very impressive but a bit more involved than I can handle right now. Still it was very informative and I learned a lot about what is involved in building one of these things and what makes them tick, thanks for posting that.

[gzig5]

I have collected most of the bits to build one, but lucked into a nearly new jewelry furnace that is 6x6x8" on the inside for relatively cheap last winter. I could build cheaper, but value my time and this has a little better controller than I would have cobbled.

[Forestgnome]

I still just use stacked fire bricks, but I use Mapp gas instead of propane. It heats much faster.

[Bob Ford]

I bought the Evenheat KF13.5. You can't justify price for what we do. This is a hobby learning experience. Much cheaper than a bar, golf, or fishing and we have things to show others that few can make or even understand how we make them.

Bob

[radkins]

fishing and we have things to show others that few can make or even understand how we make them.Bob

Yeah, fishing! After I bought my bass boat the guy who sold it to me said he was selling because to him it was just "a hole in the water that he poured money into". After two years I figured my cost per use for the times I used it and it was staggering at how much per hour in real costs of that thing was, I sold it! So yes I see your point and in the scheme of things I guess I have spent a lot more to get a lot less than what I would with that oven.

[Bob Ford]

I know a lot of people that think nothing of buying a new rifle or pistol +$1,000, but then say I can't justify $200 for a tool. Boats I fell for that too, built a 24' cruiser lots of money little show for all the effort.

Whatever you get be sure that you put a tile or thin firebrick on the floor of the furnace to protect the soft insulation. Bring temperature to about 200° and hold it for a 1 hour then slowly increase. This gets the moister out of the tile. I thought ceramic tile was water tight. Set the furnace for 1375° and turned on. First tile broke in five pieces at around the 350° mark.

Bob

[Evan]

I build things because I like to build things, not buy them. I buy things that I can't build like digital cameras. Building and making stuff is my hobby and it's what I am good at so that is what I do.

Oops, I forgot. When I was in high school I did build a video camera. It used a flying spot scanner with a silicon photocell feeding an amplifier. That was fed to a Tektronics oscilloscope along with vertical sync trigger pulses from the scanning disk. It produced recognizable images of the classroom. I got an "A" on that project.

[radkins]

I build things because I like to build things, not buy them.

Exactly why I want that oven but I have so many "irons in the fire" right now I simply can't start another project. I must say however that from what I have seen of your projects I am in awe of your ability to get things done as well as your remarkable skill to build them. I don't think I could get that much done if Santa loaned me his helpers!