heat treatment oven - question

[JPR]

All the homemade heat treat ovens that I have seen are narrow so the bricks for the roof can sit on the side bricks. My thought was to use a stainless steel strip placed into a slot in the bricks and a couple of stainless steel bolts to support the strip so the oven can be 12" wide (inside dimension).

Has anyone else done something like this?

[BobWarfield]

You could also go two layers on top, with the bottom layer of two bricks crosswise to support a vaulted brick across the gap above. Run lots of insulation in either case on top.

Also note that you could make a true vaulted ceiling for your oven using refractory mortar and make a very roomy oven if desired. That's how pizza ovens are made. The mortar is the same stuff fire bricks are made of, but you can use it as mortar between the bricks. It is good to 1250C = 2200F. Oughta work!

A 25lb bag is available for $35 from this source:

http://www.fornobravo.com/store/Inst...p-1-c-248.html

I got interested in pizza ovens and realized at some point there was crossover value for a heat treater. Worth Googling the pizza oven world--lots more pizza ovens being made than heat treat ovens. LOL

Mamma Mia, at's a spicey meatball!

Best,

BW

[WORMgearster]

I use a fiber or kao-wool block for the top and half of the sides. Brick the bottom and half way up the sides then use the thermal ceramic fiber blocks for the rest. Lighter and will last longer than the brick. They come in different shapes and sizes and density for higher temperatures.

They come with a threaded rod to attach to the metal Shell of your furnace/oven. The manufacturer I used last was Vesuveus.

Good Luck

The Worm

[lbender]

JPR,

Marinite is probably a better choice than bricks. Comes in up to 4' x 8' sheets, so you can make a large oven.

http://www.industrialinsulation.com/marinite_board.htm

[Your Old Dog]

JPR, I can't imagine why your plan won't work. Just make sure and try to use the firebrick mud to seal it off a bit.

[wierdscience]

I have the lid off an old ceramic oven at work,those bricks are just keyed together and the whole top is wrapped in a thin stainless steel band which is pulled tight with screws like a hose clamp.

BTW,I sold a ceramic kiln three weeks before I saw one being used to heat treat some big blocks of D-2.Sometimes you can find old ceramic kilns in the FS ads for $100-200.

[Evan]

You should be able to just glue the bricks together with sodium silicate firebrick cement. If you cross laminate two layers it will be plenty strong.

http://www.savemoneywithus.com/RepairProducts.html

You could also use one layer of bricks glued to a piece of high temp mineral board.

[JPR]

I had not thought of looking for a used kiln. I did a search on Craigslist last night and now the proud owner of a small 12" wide x 8" deep x 8" high kiln. The bricks on the door are chipped and need some minor repair. Also planning to install a newer thermostat.

Faster and cheaper than building one, plus I can use it today. I forgot the k.i.s.s. part. Now off to try Evan's tandem vacuum idea while heating a part.

[jdunmyer]

I was given a small ceramic kiln, about 8" X 8" x 8" inside. A digital temperature controller was found on eBay, brand-new, for about $70.00, including thermocouple and power contactor. Didn't take long to lash things together, and it has worked well for heat-treating purposes. The controller reads in degrees C instead of F, but conversion is no big deal.

It's slow to warm up to hardening temperature, and slow to cool to tempering ranges, but works great otherwise.

[lazlo]

Originally Posted by Evan

You should be able to just glue the bricks together with sodium silicate firebrick cement.

http://www.savemoneywithus.com/RepairProducts.html

Ugh, I wish I knew about that site. I bought the same refractory cement from McMaster for around twice the price when I fixed the crack in my muffle furnance/heat treat oven...