Budget brick furnace

[renkenbw]

Hey all,
I’ve had problems maintaining high heat with a handheld blowtorch. Didn’t have the money to buy a furnace. I managed to buy refracting fire bricks for four dollars each from a local ceramic store to build a small area and hold in more heat. No mortar or anything, just stacked the bricks. I took this one step further and made a small furnace. All I had to do was cut a groove for the blowtorch into one brick. I use another brick to limit the interior volume when using as a furnace, that I can remove when holding the blowtorch by hand with a regular melt dish. I also bought a small piece of ceramic wool for the top from the same ceramic store. I will attach pictures.
This has worked out really well to use as an area for hand melting, or as a makeshift oven for higher temperatures.
The top three pictures show the bricks stacked for use as a furnace. First one shows it opened up for access and the second and third ones show the furnace in use. The bottom two pictures show the bricks configured for hand melting when using a regular melt dish.

 

[anachronism]

That looks really good.

Put some plasterboard- (I think you call it gyproc?) over the top of everything and it gets even better.

Jon

 

[snoman701]

That looks really good.

Put some plasterboard- (I think you call it gyproc?) over the top of everything and it gets even better.

Jon

gypsum....we call it drywall.

Instead of drywall, get yourself some kind of metal. poke holes, stainless wire of some sort. Washer on the hot side, just a twist on the opposite side. You are just putting the wire through the cerwool, then using the washer to keep it pulled up against whatever metal you use as a backing plate. If you don't do this, the cerwool will stretch over time and won't hold shape.

be really careful with the cerwool...after you fire it to heat, the fibers of it become equivalent asbestos and can cause mesothelioma. So just be careful.

Looks good though...I do something similar with loose bricks just to make odd shaped forges for heating metal. Works great!

 

[anachronism]

So use plasterboard- it doesnt have the same risks 8)

 

[Johnny5]

Some years back I used to build my own furnaces for refining and casting. I found a gentleman on craigslist that had aquired a storage unit with many cases of ceramic fiber (blanket) insulation. He gave me a good deal, so I bought all that he had. It worked very well, weighed very little, and was highly portable. All I did was line the inside of a galvanized trashcan with the blanket, using thick mesh wire to support it up, and I used a propane roofing torch ($20 new) as my heat source. I could get it over 2000f relatively fast. The only drawback was that it was rated for 2800f.
The top piece is rockwool but I only used that because I obtained several bats for free, and I only used it temporarily.

 

[cosmetal]

Use "soft" bricks when lining your chamber. They absorb less heat than the "hard" bricks so more energy is available to heat the object you are firing.

Also, both hard and soft fire bricks are available in 1/2 sizes to help save physical space in your furnace design.

Hard Fire Bricks vs Soft Fire Bricks:

https://refractoryfurnace.wordpress.com/2015/04/28/hard-fire-bricks-vs-soft-fire-bricks/

James