What to build with 4 cases of extra fire brick

What do I do with 40 extra bricks

  • Tempering Oven

    Votes: 0 0.0%

  • Low temp salt pot

    Votes: 0 0.0%

  • Save for a rainy day

    Votes: 0 0.0%
  • Total voters
    0
JTknives

JTknives

Blade Heat Treating www.jarodtodd.com
Knifemaker / Craftsman / Service Provider
Joined
Jun 11, 2006
Messages
8,647
If you looked at my oven post I was shipped the wrong bricks in my order. I ordered K-23 and thy shipped my TC-23. Thy are basically the same brick except the TC-23 bricks are the K-23 rejects. So the company is sending me my correct order free of charge as I paid more for the K-23 then what thy sell the TC-23 for. Thy wanted my to box the TC bricks back up and ups would pick them up for me. So I asked them if I could buy these from them and he was more then happy to sell them as shipping was $80 for 4 cases. After doing some math he excepted my offer of $15 a case.

So now I have 8 cases of bricks, 4 are for my heat treat oven build and the other 4 are well I don't know. This is why I'm here looking for your advise. Since I'm in the building mode my first thought was to build a separate tempering oven. Would be simple and easy to construct. Then I remember when I was reading about building a salt pot guys where in love with there low temp salt pot. So what do you think, low temp salt pot or tempering oven. Thanks guys for your help
 
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I want to do a salt pot but they scare the hell out of me :eek:
 
Thinking low temp, 300-600 deg
 
Considering that I've seen a fair number of folks who temper in toaster ovens and kitchen ovens, firebrick insulation for a tempering oven does seem like overkill... If you do enough OA torch cutting, welding or brazing, or plasma cutting, a firebrick topped "hot" work table is handy.
 
What is a low temp salt pot for? I haven't come across it yet in anything I've read, I've overlooked it or it has to do with a process I haven't really researched in much detail.
 
A low temperature salt pot is used for marquenching. The hot blade is plunged into the 400F molten salt which rapidly drops the temperature to the Ms. It then remains there until you remove it and let it air cool slowly to ambient. This greatly reduces warp and allows more control over the cooling curve. While it isn't the right choice for the fast quench steels, it is superb for the slower quenching steels. IIRC, it will also work for air cooling steels.

The same pot can be used for nitre bluing of blades to get that intense peacock blue color. It is regularly used to color damascus blades and billets.

Low temp salt pots are far safer and easier to build and operate than their dangerous high temperature cousins. Many use an old pottery kiln as the heat source and a 4" heavy wall stainless tube for the pot. The salts can be purchased very reasonably form HighTempTools and many other suppliers.
 
I have a welding table with firebricks as the top. It is a HF rolling cart with the bricks stacked in the top recess.
You can use a torch on it to do copper soldering, silver work or brass brazing, or mig/tig welding steel. The welder and other welding supplies are stored on the shelves.

I made a welding table before this one with poured refractory on the top, and it was HEAVY. It also sucked up and stored the heat a lot more than the fire bricks.

I have seen a large vertical forge made with soft firebrick insulation. The bricks were beveled so they fit tightly in a circle within the shell. They were then covered with a 1"+ thick poured refractory core. This made a robust welding forge that stayed fairly cool on the outside. It also stayed evenly hot on the inside.
 
Thanks guys for the comments.
Stacy what do you think I will use more. I have a nice heated 5gal quench tank with AAA quench oil and a tall sword height tank with canola. The heat treat oven I'm building is going to be mostly for doing the things I could not do befor like stainless and air hardening steel. But I will of corse use it for all my other steels. I really like the idea of low temp salt pots but I don't ever really get much warping in my blades in the AAA as long as I normalize it and reduce grains befor quenching. I guess what I'm wondering is this. Is there any amazing advantage with a lot temp salt pot that I will be missing out on when just using quench oil and a tempering oven.
 
No, it is a nice thing, not a necessity. I would think a dedicated tempering oven would be the best single thing you could make. Make it deep for long blades. 12X24X8" would be good.
 
I agree with the tempering oven. It takes 3 hours or more for my oven to cool off enough to temper in it which kinda sucks.
 
If you make the control box separate and connect with plugs and sockets, you could make a tempering oven that is exactly the same as the Austenitizing oven. This gives you redundancy, which is always nice to have when things go wrong, which they tend to do when it's most inconvenient.

If you run it on 110V for tempering, you'll have only one quarter the heat input, making it easier to get the tight control that we want at low temperatures. The electronics will usually cope with the change from 220V to 110V without problems. If you are using an electromechanical contactor with a real mains Voltage coil, it will not cope with the different Voltages. To get round this, you can fit a Switch-Mode Power Supply to power the contactor circuit: I'd go for 24V DC, as it's an industry standard and a nice low Voltage for safety.
 
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