Trouble-shooting one brick forge

J

JoshEarl

Joined
Sep 30, 2007
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197
My firebricks came today :thumbup:, and I managed to get a chamber and heat hole carved. I wrapped the whole thing with coathanger wire to keep it from crumbling.

I have a little (about 4.5") neck knife that I'm working on, and I decided to test my forge by trying to anneal this piece of steel. It's made of the hot-rolled 1095 that was dulling my drill bits earlier. :rolleyes:

I was able to get part of the blade hot; the spot where the torch was hitting got to dull red. I couldn't get it any hotter than that.

Where do I start to figure out what I'm doing wrong? I have a regular plumber's torch, not the adjustable one that Wayne Goddard recommended.

Also, what should the chamber look like? It gets orange for a couple of inches near the fire hole, but the rest is dark-ish.

Thanks,
Josh
 
The regular plumbers torch dose not put enough fuel/air mix out to get the brick hot evenly. once the brick gets hot it radiates heat through out the chamber and you can cut back on the gas pressure.
 
You are describing all the problems with a one brick forge.
Not enough heat
Insufficient chamber size
Too much of a hot spot

These problems can be minimized by increasing the chamber to the max possible, using two bricks,getting a better torch unit, or building a proper forge. The last choice is the one you will eventually go with, so the sooner the better.
Stacy
 
A burnsomatic (sp) will produce more heat, try to get the hole in a spot where it gives max heat. Get 2 bricks and enlarge your chamber.
Cheers Ron.
 
My chamber is fairly small right now. I thought smaller would mean more concentrated heat, but it sounds like a larger chamber with more airflow is better.

Thanks for the pointers! :)

Josh
 
Josh, what burner are you using?? I know that the Bursamatic JTH7 has been recomended in the past but things have changed..The Bursamatic ts8000 is the hotest small burner that you can get..pick one up at home depot/lowes etc.. Do yourself a favor and use the map gas instead of propane with it, you should get a lot more heat with this combo..Also do not put the burner tip directly in the hole. It will not get as hot and you will melt the torch tip..Keep the tip about 1/2"-1" from the hole. Hope this helps!!:o
 
on my jth7 i removed the tank pin pusher downer on the torch and removed the metal filter cake from the pusher downer then put it back on the torch. i lets more gas flow. do this at your own risk, im not incharge of your safetey. im also going to try increeseing the burner orafacis (damn i cant spell, but i can make knives)
 
Interesting, I will be following this thread closely since I just ordered 3 fire bricks to make my one brick forge.

I bought 3 because I know they break very easy but maybe it will be better to make a 2 brick forge by hollowing out half of the cavity of two bricks and then using the wire to hold them together?

Now I am second guessing what torch to buy...
 
donm1234 said:
Interesting, I will be following this thread closely since I just ordered 3 fire bricks to make my one brick forge.

I bought 3 because I know they break very easy but maybe it will be better to make a 2 brick forge by hollowing out half of the cavity of two bricks and then using the wire to hold them together?

Now I am second guessing what torch to buy...
Click to expand...

I used two bricks in the way you describe. Hollow out half of each and wire them together. I also use a Benzomatic JTH7 and it gets blades hot real quick and that is without the valve even close to wide open. I cut the torch hole at an angle to the top of the brick so the torch doesn't point right at the steel. It points at the "ceiling" of the forge to try to get the heat to radiate more evenly. My chamber is an oval about 2"x3". I also put a small hole in the back to vent gasses, but I am not sure that was smart since I now keep that nearly closed off with a third brick. An added benefit to using two bricks is you can carve it out with a dremel with a stone attachment and it is very easy.
Stacy is right, I am already building a real forge and I have only made 4 knives using the two brick forge. It definitely works, but has too many limitations.
-Mike
 
Mike's description is about the same as the one I posted the photo of, including the burner, my burner hole is large enough to tilt the burner around in the hole, forward or backward. I also would put a small brick chip in the chamber to get the blank up off the floor of the forge.
You can buy bricks from any local pottery supply store, save on the ordering costs. With a little patiens you can get these things really cooking and forge or ht small blades, I can do up to a 5 inch blade in mine, the tang sticks out, in the photo you can see my doors, they can be slid up a little and then the tang can stick out without opening up the whole opening, this saving a little more heat.
I cut slots in the brick with a hand saw and broke the slabes out with my hand, to make the chamber, and used them for the doors and chips to prop up the blade inside the chamber.
Cheers Ron.
 
I see it! not sure how I could have missed it. I assume it is sitting on the wood frame for display only, I am thinking it would get to hot for wood!
 
Here is my version of the 2 brick forge. Maybe it can give you some ideas.

forge1.jpg

forge2.jpg

forge_door1.jpg

forge_door2.jpg


I've changes a few things since the pics were taken. I put the back stop flush against the back of the forge so I can close it up and changed the angle of the door lever for better movement of the door.

If you have any questions don't hesitate.

Pad
 
I can see you put a fair amount of thought and work in building this 2 brick forge, very nice.

With the bricks housed in steel is there a noticeable transfer of heat to the steel resulting in a longer time for the forge to reach temp? Of course this would mean more propane usage.
 
Very nice forge ther Pad. Mine is a more of a put together in a hour and use until it turns to dust.
Yes it is sitting on that stand just for the photo, but suprisingly it does not get very hot on the outside and I can touch the "doors" with my hands and they are not really hot. The bricks are very good at keeping the heat. Do build a good support for the burner the last thing you need when you are concentrating on a blade is a hot torch rolling around your shop.:eek::mad::foot:
Cheers Ron.
 
donm1234 said:
With the bricks housed in steel is there a noticeable transfer of heat to the steel resulting in a longer time for the forge to reach temp? Of course this would mean more propane usage.
Click to expand...

I did not know that. Will it keep the heat longer than not housed bricks?

Pad
 
Very nice forge Pad. I use a single brick for the ocasional small job and with a map gas it works great for the odd small project where I don't want to fire up the main forge. I would like to build something just a bit bigger and have it set up along with my main forge. How's the fire brick work compaired to ceramic wool?
 
Sorry Will, this is the first forge I built so I can't tell you about the wool. I know that it seems to work great for small work and I only use propane. But sadly I don't have a frame of reference to compare it to.

Pad
 
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