Two brick forge advice

I recently built a paint can forge, with a few inches of of the high temp wool and a good layer of satanite. I placed the hole on top of the circle for a swirl, but in the middle, and straight in....not angled. 1080 got non magnetic FAST. I don't know how hot my set up will get, as I've only heat treated. MAPP Bernzomatic is what I'm using. Here is what I was thinking about an angled burner, as the gentleman has built. Since the flame would be traveling (relatively) down the chamber in an angled setup, as compared to a flame traveling directly across and off of the opposite side, I would think the overall temp would be lower. I'm just guessing that a perpendicular flame will be hotter, in a more confined area, where an angled flame will be more even, but lower temp. I would still think, that if you're able to close up the front and back except for a slot on both for your work/tools, an angled burner might be better design...as long as it's even and hot enough for what you're trying to do.
 
I know this is conjecture, but it fits my intuition as well. Thanks!

I just fired up my tbf for the first time a minute ago. I put the hole in the middle top but realized I can angle it a fair bit if that helps. I only have a propane tank for the either mapp/propane torch but it sure LOOKED like a tiny little forge. Took a minute but started glowing. It's only just early evening here, not full daylight but not yet dusk. I'll fire it up again when it's dark, and this time I'll try sticking metal in it and see.

Thanks!
 
Hank: I've built and tested forges with all three locations both angled and straight in. Front and back should both be angled, in the middle is straight in. Straight in at the middle is aimed for heating up a single spot with a big burner. A little below the top of the chamber and angled front or back give the most complete combustion and work better with smaller torches. Big burners have enough BTU that it doesn't matter in such a small forge. I have settled on having the torch at the front because it means I have to put less of the blade in, which helps with smaller blades.

Just my 2¢
 
My primary forge for over a year has been a vertical 2 brick set up. The bricks were about 5x4x10 hollowed out and stuck together; the inner cavity is about 6x4x7 and coated with ITC-100. I then wrapped the whole thing in 1/2" of refractory blanket and slapped on satanite to keep the fibers from getting airborn. It has hole on both sides to pass blades through.

With a 1/2" burner from hybrid burners I get it to over 2000F. A bernzomatic adjustable torch connected to my propane tank can hold from 1100 to 1600 for heat treating/normailzing smaller stuff.

Having it vertical prevents the hot spot you get from the horizontal config, but of course it's harder to heat treat longer blades with it (anything up to 6" is fine tho).

You can see it in the right hand side of this image beyond the blade and the anvil. This blade was forged with the vertical 2 brick forge.

IMG_1152.JPG
 
HankG said:
So you like the location of the flame hole? A bit toward the rear and off center toward the top, angled to the front? This is the only build I've found in searching that addressed the placement in terms of all three of those aspects. Most just stick it in the middle, a bunch put it near the top, some place it toward the front or rear, none angle it that I've seen.

Thanks for sharing your results!
Click to expand...

Sorry for the delayed answer.. yes, generally i like the placement and angle of the hole for application where more uniform heat is required. The angle spreads the swirl more through the chamber. Don't close the holes because of the back pressure, the gases needs to go somewhere. The diameter of the chamber is around three inches, measure the brick, and you will get wall thickness. The wall thickness is not so important as roundness of the chamber is. So, what do you think of the two brick forge so far?
 
No problem for the delay, thanks for responding. Your thread here did a great job of showing what the considerations are in designing one. There aren't that many, but not having ever seen on in person I would have missed half of them.

My forge is working great, though I've only used it a few times for heat treating. I made it quite similar to yours. I can vary the angle of the flame well enough to get either a strong hot spot or a much more even temperature. It heats up very quickly. The bricks cracked but are held together well. I got some sairset to coat the inside and a couple bricks to make a second if I decide to change the design - so far no need.

I need to order some tempilstiks but the plane blade I made turned out great. After I repeated the HT, straightening it properly this time, it is straight and so far holds a very sharp edge despite seeming harder than the few quality plane blades I have. I'm basing hardness on how long it takes to remove metal when sharpening for the first time, no idea how large a difference it translates to. I may have to temper it again to a higher heat but so far the edge is holding great. It is a shoulder plane blade used for fine tuning the end grain on mortise and tenon joints so a very keen edge is important and it won't be subjected to heavy cutting, but most of the cutting is done right at the very corner edge of the blade. I'll have to see if the edge holds up.

I can't find the cable to my camera but it isn't exactly pretty in form: a tall, narrow "T" with the edge at the very top," but it looks and works just as it should :)

In other words: Wow, I can make these things and even kinda control how they turn out. That is so cool!

Thanks for your help.
 
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