One Brick Forge Tricks?

Chiro75

Chiro75

Joined
Feb 4, 1999
Messages
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What's the secret to getting a one brick forge really hot? I made my first one last night but I still had a lot of trouble getting consistent heat over a 6" blade. I think the problem could be in the construction, so here's what I did:

Because the place I bought my bricks out didn't have any big bricks, I had to make my "one brick" forge out of two. I hollowed out a full length half round in one of the bricks (for feeding in the steel), and another little half round for the tip of my torch (propane). I set that brick on top of another one. I wonder if there was heat escaping from the gaps? Also, I used as small a channel as I could, so do I need to make a bigger hollow? I adjusted the flame so that blue flame was firing out bothe ends of the forge, then I passed the blade back and forth (in/out), but it was tough to get consistent heat. Anything?
 
OK, first off, I have NO experience with the one brick forge Chiro, so I'm just trying to guess things that might help outta my GOddard book. I would definitely suggest $50 knife shop as a worth while investment though.

First off, can't just use a regular hard brick(according to him), HAS to be a real firebrick.

secondly, can't quite picture your setup. But Goddard says 1" hole through longest axis of brick. This is for the knife. Then perpendicular(and I KNOW that's not spelled right, but can't figure out it for the life of me. :) ) to this hole, in the center of the brick going through thinnest axis, drill a hole from outside just into until it crosses the knife hole. This should NOT go all the way through. Both of these holes are 1"

And this could very well be EXACTLY what you already have. :) I sincerely hope it isn't though, not s that I can say you're doing anything wrong, but so that this typing might actually contain something helpful. :)
 
Chiro,
I think your trying to get too much blade done with the one brick forge. Mine is useful for blades under 5". Over that length I started running into heat consistancy probs. I built mine from instructions found in Goddard's "The $50.00 Knife Shop" so etp777's description sounds right to me. The OBF is really best when used on smaller jobs. Tangs, 4 1/2" blades and such.


All the best,
Mike U.
 
I could not get an even heat with the first one i made, but it was made from the hard light brown firebrick, i looked everywhere near where i live and finally found 1 place that sells the white soft firebrick. it is very soft, you can push your finger into it, it is so soft. I used a piece of tv antenna pipe to cut the hole all the way thru from one end to the other and a 1" wood drill bit to cut the hole in the middle on the side for the torch to go into. I use the propane torch with the flexible hose and leave it about 1/2 to 3/4" outside the brick. I actually made 2 from soft firebrick and put them end to end so i can do longer items. with just one torch i can still see flames come out the 2nd brick. I have heated up over 6" to a pretty even color and it is over magnetic in very little time, i have a speaker magnet next to the little forge to check with.
 
If you can't get what you want out of your 1 brick I can send you come plans for a steel pipe forge about 16 inches long. 10 in diamater. I built it a couple of months ago. Just no time to take full advantage of it. It is nothing special I have seen a number of variations of it on web sights. The latest thing among the guys here is to put the jet inlet about 1/3 in from the front and at a 15 to 30 degree angle. It uses a back end. The flame spirels down the pipe runs around the back and comes back out the front. When
clean you can see the ashes from the start up paper really swirl.

It also uses a presure regulater so you can set the presure for hotter for welding or not so hot for forging and heat treating.
 
i was told the secret to the one brick forge is GOOD propane torch. not the $10 model but the $35 turbo tip.
 
the propane/mapp torch i have for mine is the Bernzomatic JTH7 with the 3foot hose so the bottle is not near the heat. Seems to work pretty good so far. I was playing with making some small cable damascus this week, and seems to do ok so far, using just regular propane, for the 3/4 inch peice of cable i used the mapp to weld the end of it, but havent done any more to it yet.
 
The MAPP gas torch I have has a rose bud tip on it and it throw alot of heat,I bought it from lowe's for 39 dollars.
 
I'm planning to use a steel empty oxigen bottle.
I sawed it open, cutting away one end. The other end is still closed. it's about 10-12" long and about 3-4" in diameter.
Where I should place the burner hole? Should I line it with some kind of refractory?
 
The one I made is from a 18" length of 6" sch 80 pipe. Two inches of refractory lining. the side hole for the torch is slightly higher than centerline. The flame flame swirls very well. Adjust the torch in or out till very little flame comes out the front.(one closed end) This gives me an almost controled atmosphere. Small piece woodchip will turn to charcoal, then swirl and out the front. Drop me a line and I will try to draw you up something. Paul
 
I've used a one brick forge with a propane torch but it only got small sections really hot. I could weld about an inch at a time and that was by using a hair dryer or heat gun(hot air blower) to force air into the forge. I blow air in beside the propane flame, sort of turbo charging the one brick forge. Also it takes a fair amount of time for the forge to reach a suitable temperature.
My really big improvement was to buy a bigger torch head for the burner. The biggest burner commonly available in Australia uses 250 grams of gas per hour, by going to a specialist gas supplier I got one that burns 1200 grams per hour, and it really roars. It was far too much for a one brick forge so I made a 4 brick forge. You can buy special cement to bond the bricks, I got some from a pottery supply store together with the bricks. I can now heat up sections that are the length of the forge, about 8 inches and I can get away without using the hairdryer. Although I still use it as the gas burns more efficiently.
Keep experimenting its great fun
Regards
Pinpoint
 
Originally posted by p moore
The one I made is from a 18" length of 6" sch 80 pipe. Two inches of refractory lining. the side hole for the torch is slightly higher than centerline. The flame flame swirls very well. Adjust the torch in or out till very little flame comes out the front.(one closed end) This gives me an almost controled atmosphere. Small piece woodchip will turn to charcoal, then swirl and out the front. Drop me a line and I will try to draw you up something. Paul
Click to expand...
No problem: your explanation is very clear.
WHat type of refractory lining did you use?
The Kowool thing (not available in Italy or refractory cement?
 
For refactory products try your pottery suppler. Ask them or look up the phone book for someone who manufacturs the kilns for backing the pottery. They should have all the contacts of where to get the lining. In kilns they often just use the wool without a coating. A coating of thermo coat (like a thin clay paint)protects the wool from
being eaten by the flux.

If not they sould at least be able to sell you some bricks to make your one brick forge while you search.

I also have plans if you want.
reg_ellery@optusnet.com.au
 
The only place i found locally that sold the soft firebrick and also the Insowool (kaowool type stuff) is a boiler sales and service company. The insowool stuff was less than $5 a square foot, i lined 2 coffee cans put together last night and seemed to do really good.
 
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