Help w/ One Brick Forge

[me2]

I have ground a small blade about 2 inches long from O1. Today I tried to harden it using a soft fire brick w/ a hole through it and one from the side. I was using MAPPS gas for fuel. The blade didnt get hot enough, and the brick cracked through the center. The chamber of the brick didnt seem to get hot enough, but I only let it heat for about 5 or 10 minutes. What am I doing wrong? Will this set up be sufficient, or do I need to try something else? I'd like to be able to harden up to 5 inch blades. If this setup can work for the 2" blade, will it handle 5"? Assuming I did something wrong on the first try and the whole setup will not have to be scrapped. Thanks for any help.

PS: I read some of the search items, and people said their one brick forge worked great. I'm just a tad frustrated, and dont know where to begin to fix it.

 

[FOX-]

I don't know but it is cold out, correct? Bricks heated up on the inside but remained cold on the outside causing them to crack, I think...

 

[me2]

I didnt think it was terribly cold, just like 65-70 or so. I am in NC too. I did it this afternoon, about 4 pm. It was sunny hear, and we had some cool sky writing from the Air Force from Seymore Johnson.

 

[Laredo7mm]

Try this thread:

One Brick Forge

Sounds like you need more BTU's.

Soft Firebrick always tends to crack. It is pretty fragile stuff.

 

[me2]

I'm still trying to figure out what happened. Most of the blades I want to make for now are only 1-1.5 inches wide. I may have the hole too big, since its an oval 1" by 2". I also may close one end and see if that helps. I'm gonna get up bright and early and try again tomorrow.

 

[AwP]

Alot of one brick forges I've heard about either have a frame built for the brick, or it's supported all around by other bricks.

 

[ddavelarsen]

The chamber in mine is much smaller, maybe 3/4 X 1 1/4. Before I fired it up I wrapped it in wire and so far it hasn't broken yet, but if it does that's probably no big deal. I usually set it up surrounded by a few hard firebrick, and block one end. I've been able to harden small blades just using propane. I'm sold on the thing, I hope you get yours running the way you want.

 

[me2]

Thanks for all the advice. I'll try again later this week, but I saved the pieces and will probably block one end, and use a smaller hole. I gotta figure out how to drill the holes faster. It took like an hour last time using some threaded rod and just hand power.

 

[Ripper]

What torch are you using?
From what I've read about this style forge is that it works best with one of the turbo torches; either the JTH7 or JT539T .
Regards,
Greg

 

[ddavelarsen]

I drilled mine just using a spade bit for boring wood. Went pretty fast.

 

[happycat]

You defnately want a jth7 or similar torch. They burn much hotter than a regular torch. You can get them at lowes or home depot. They have a 3' hose and a handle at the torch end. You definately need to block off one end of the chamber, and keep it smaller rather than larger. They also reccomend coating it with furnace cement to increase the efficiency.
Ed