Frustrated with 2-brick forge

Gabriel Kierulff said:
did you drill this holes yourself or you bought the bricks already like this? If you drilled it, how did you do it?

I'm about to build mine, just bought my bernzomatic Ts4000
Click to expand...

I did not drill I hand scraped with a big metal spoon.
And sanded with a huge file wrapped in 60 grit to get the smooth straight hole.

My burner enter from the top left side.
I use regular propane camping fuel cylinders.
 
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That is nice work for your first efforts! I think if you spend a little time hand sanding your blades, you will really see the value in it.
 
@kdogmcg Thank you! I fully plan to polish the blades more. This was just the initial grind (80 grit), leaving the edge about a quarter thick to hopefully avoid warping in heat treat. They still need the final grind, a lot of finishing work, and an edge. Those photos were just me using the rough blades to start building scales/ handles.

I noticed with the improved torch that there is plenty of heat, but I can see how I am not getting the swirl I need. The front 1/4 of the chamber isnt getting nearly hot enough. Gonna play around with the torch angle and roundness of the chamber to improve.
 
Roundness, contrary to what DiamondBackIronWorks says, is the key to an efficient forge. Without the proper swirl it is a blacksmith forge, not a bladesmith forge. I dug up a couple old images to show this, one of which is with the aforementioned MT245C. Yeah, you definitely don't need MAPP. It'll get expensive real quick.

That said, I'd trade you a burner & regulator and 2 new bricks for that friction folder. Then we'll all see what you can do with a proper forge.

View attachment 615360View attachment 615361
 
I found my video of the first trial run of my forge...
As I said earlier, I put a fire brick in back now to adjust the heat. Some times maybe just about an inch of opening in the back.
I use my cigarette to adjust the vortex/ swirl with puffs of smoke.
And you can see the draw from the front with smoke.
Not the healthiest way but it's what I had on hand.
 
Atlas Knife Company said:
Roundness, contrary to what DiamondBackIronWorks says, is the key to an efficient forge. Without the proper swirl it is a blacksmith forge, not a bladesmith forge. I dug up a couple old images to show this, one of which is with the aforementioned MT245C. Yeah, you definitely don't need MAPP. It'll get expensive real quick.

That said, I'd trade you a burner & regulator and 2 new bricks for that friction folder. Then we'll all see what you can do with a proper forge.

View attachment 615360View attachment 615361
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That swirl!!

I am going to use a hole saw this weekend to get a perfectly round cavity and try again. I have a couple larger blades cut that I know are going to be difficult to heat as-is.

Thanks for the regulator offer, but this one is already scheduled to go to my dad. He was kind enough the buy me some supplies along the way so I told him I would let him pick out materials and make him a pocket knife.
That said, I'm thinking I might want to order the burner anyways. I am kind of tired of messing around with these lower solutions, and you have been a big help on here. Going to look at finances and see what I can do.

EDIT: Ordered the 30k Atlas. :)
 
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Can anyone help me out here? What external surface temperatures do you get with such a 2BF? If properly coated with refractory cement on the inside, why couldn't I just wrap the bricks in aluminum tape rather than hardware cloth? I've been planning to build one this weekend, but wanted a little feedback from you experienced guys first.
 
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Your torch isn't powerful enough. I have the exact same one, and had the same problem. I am also wondering what to do about it, anyone know?
 
Sorry, I never noticed your question, LoD. On a well used Atlas, you can expect around 400°F on the outside of the metal shell, even higher at the front and back near the exits. Without a metal shell to dissipate heat, you can probably expect 500°F and above. Aluminum tape uses adhesive which burns well below this temperature, then the tape falls off.

Jake, I don't quite understand what your question is. What exact same torch do you have? I've forge welded a small sample with an MT245C, so it will definitely get hot enough to forge. OHaple ordered a burner and reported to me that it made a huge difference.
 
I guess I am asking what a more powerful, hotter tip would be. I have the same one that the guy who posted the thread has. After a very long time and a few different tries, I simply couldn't get the metal hot enough. It barely got to a very dull red color, at night. I came to the conclusion that the torch tip wasn't hot enough. Was I not doing something right?
 
Read the rest of this thread, Atlas just re-mentioned the two that are great. The MT245C and his own burner. If your forge is a DIY, you might have to troubleshoot that too.
 
Hello everyone I've tried both designs ( the two brick one and the one suggested by the atlas knife company). Sorry but I had the make the tests during the day, I'll try later to make them at night

two brick forge:

j9R1xCj.jpg


bLbW5Bk.jpg


sbMk5r4.jpg



a small video of it working:

[video=youtube;KD7tDWGVPzI]https://www.youtube.com/watch?v=KD7tDWGVPzI[/video]


Now the design suggested by the atlas knife company:

Dg1k1DL.jpg


rB8Jeo8.jpg


gHCrUCH.jpg



and a more complete video of the process:

[video=youtube;nvpXxkEM3W8]https://www.youtube.com/watch?v=nvpXxkEM3W8[/video]



My impressions:

In both cases I was expecting higher temperatures, which could be explained by the diameter of both holes (6.5 cm). Altough I meneged to put both test knifes on the austenitic temperature ( seen by using a magnet) and on both cases I was quite happy with the file test.

On the Two brick design I had to put those bricks on the back in order to retain more heat but on this desing I got a better circularity of the forge. Now, I'll try to make a second two brick one with a smaller diameter ( 5.5 cm)


thanks a lot for the tips and information guys!
 
Are your forge bricks k23 ifb?
Are they the same as the ones supporting your forge?
 
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The k23 may be brand specific, but they're rated at 2300 degrees. They're real soft and fragile. Just checking because when I built my first two brick forge I used "fire brick" from a local supplier and there were the wrong ones.
 
I think the K (for kiln) factor is a measurement of how fast energy travels through an insulating refractory firebrick. I believe the higher the number, the slower the rate.
 
Gabriel Kierulff said:
what is k23? the ones supporting the forge are fire bricks as well but harder, different ones.
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Liberty_or_Death said:
I think the K (for kiln) factor is a measurement of how fast energy travels through an insulating refractory firebrick. I believe the higher the number, the slower the rate.
Click to expand...

well, all I know from my local supplier is that they resist until up to 1400 degrees celsius. I know nothing about this coeficient K. I believe it worked tough... but I'll go there one more time and ask some more technical question and ask if they have different ones.

thanks for the tips guys
 
The tip of your torch shouldn't be so far in. The brass will melt if it's in the chamber and the forge is working right.
Second, not sure that you'll get enough BTU from that torch, even with MAPP.
Third, 6.5cm(I use 67mm) is ideal for the chamber to insulation size on a 4.5" square brick. (I love mixing standard and metric!!!)
Fourth, the torch angle looks much better in the last video. Wholly inadequate in the pictures and first video.
Fifth, resistance to heat isn't the same as insulation. Seeing that you easily carved the bricks, I'm going to figure that they are insulating. Another way to be sure is if they are heavy or light. Heavy bricks don't insulate, light ones do.
 
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