Darlhim

Building a small fire brick forge

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I'm looking to build something tiny for knife making.

My idea is to weld an angle iron frame to hold everything together, and I'm going to use a few bricks and use a hole saw to drill a 2" hole down the center and stack them together.

My questions are

Is it better to leave the back end closed or is an open tunnel more effective?

Is it worth constructing my own burner for something that small or should I just drill a hole and stick a propane torch in?

If propane torch, is it worth investing in a swirl flame tip or is a pencil flame fine?

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Also if I built my own burner, will I get more pressure/volume out of a camping cylinder as I would 20lb cylinder or would the heat output be equal?

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I did both a little firebrick forge and a small pipe forge with a MAPP gas torch before I built a burner. MAPP is getting hard to find, when ever I'm at a garage sale, in an actual garage, I always look for those bright yellow MAPP cylinders.

 

Try it with a torch first, see if you get enough heat to forge with, you can always build a burner if the torch won't get your work hot enough.

 

the size of the forge chamber will be the determining factor if a torch can get you to the heat you want. I had no problems getting to forging (but not welding) heat in the pipe forge (a foot of 8 inch pipe, an inch of kaowool, firebrick floor)post-182-0-98071800-1403032067_thumb.jpg. the brick forge was a soft firebrick, hollowed out with a spade bit, but only used for annealing and heat treating moulding plane irons.post-182-0-02014400-1403032257_thumb.jpg

 

definitely leave an opening in the back for longer work, you can always cover it with a firebrick to keep the heat in.

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I'm only looking to make a small 2" or so chamber maybe 6" long.

Would putting a 2" steel pipe inside the 2" tunnel in the fire brick benefit me at all or will bare brick be ok.

This is just going to be for knives and maybe some random stuff here and there.

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Guys been making 2 brick forges for bladesmithing for years. A bernzomatic type torch will work for forging. A mapp gas torch is enough to weld if you do it right.

 

If you build your own burner, a 1/2" T burner is more than enough to melt your blade to a puddle if you turn it up too high or don't pay attention.

 

Frosty The Lucky.

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Not sure what you mean by a "camping cylinder", the short, fat cylinders that a camping lantern runs off of?  Too small for a naturally aspirated propane burner.  I use a 20 lb, Barbecue type propane cylinder, an easy swap or refill here in California.

 

A lot of people use larger tanks for propane forges. I've seen (and lusted after) 40 lb cylinders on some souped up grills, residential propane users frequently have 100 lb tanks and many smiths will link up multiple 20 lb cylinders to keep the evaporative freezing to a minimum.

 

back to the torch, I would think a swirl flame nozzle would be more effective than a pencil tip. 

 

Where are you located?

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You can use the small cylinders but they'll freeze up shortly before they run dry, say in 10-15 minutes. A 1/2" burner will run all day long on a 20lb. tank but a 3/4" burner will freeze a 20lb in a couple hours, a 40lb tank rill run a 3/4" burner all day. IF it's shirt sleeve temps and that's shirt sleeves for you folk in the lower 48, we tend to think anything over 45-50f as shirt sleeve weather.

 

Oh boy, I can see I'm going to be rambly today.

 

Frosty The Lucky.

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So, to make this burner am I just putting a 1/2" T together with a 1/2" pipe, and attaching a propane source
To a mig welding tip?

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So, to make this burner am I just putting a 1/2" T together with a 1/2" pipe, and attaching a propane source
To a mig welding tip?

 

Look through the gas forge section for the T burner. Read up on it and I'll clue you to the mig tip (jet) size. See if you can determine the correct tube length and T size.

 

I don't want to put you off asking for help but I've posted I can't count how many times repeating T burner directions. I'm old and cranky so I'm much more likely to help folk who do some reading first. It's all there from the basic ratios to construction methods and tricks.

 

Frosty The Lucky.

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I'm only looking to make a small 2" or so chamber maybe 6" long.

Would putting a 2" steel pipe inside the 2" tunnel in the fire brick benefit me at all or will bare brick be ok.

This is just going to be for knives and maybe some random stuff here and there.

If this was answered already I missed it and please excuse me. The problems with a steel lined forge would negate any benefit IMHO.

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I would look into the Wayne Godard propane forge set up, his is smaller (one brick) but he runs it on a berzomatic propane torch and has plenty of heat for blade work. The book is called the 50 dollar knife shop and I highly recommend it anyway.

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Can't post reply? Its telling me I don't have permission if I try to post what I am trying to ask...XXX

 

Is it an issue if the propane line im using is a pre-set BBQ regulator hose? I'm feeling like it doesn't permit enough gas flow.

 

Right now I have basically achieved a bunsen burner on steroids.

 

1AF01A85-E8EB-4C83-B296-DFA6443E32B2_zps

 

 

How is this burner built? It seems substantially simpler than any other design but is there some secret to it? The main thing I notice is the 20psi regulator. Which is technically double the 10psi output fixed one I purchased at home depot.

burnernew_zpse2a77a79.jpg

 

 

 

Also, did I get the wrong bricks? The mason supply yard said these were the fire bricks they carry. They aren't as soft at all as the other bricks it looks like everyone else uses. I had to use a carbide grit hole saw to get through them....

 

D52826F9-F2E6-4D23-ACD0-ED5350C0075A_zps

Edited by Moderator54
initials and acronyms of TOS banned language is also banned.

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Looks like your posting just fine ;)

 

Yeah the BBQ reg won't work. Better off with one made for a turkey frier but best source might be propane supplier. I also recommend a guage that can register 0 - 30 psi.

 

What is the heat range of the brick? You want 2600ºf or higher. I typically melt 2300º f Insboard doors on my freon tank forge. (Albeit, I'm running a 1" T-burner :D )

 

Edit: Just saw the 1/2" pipe size. Not sure but guessing you wont need 30 psi ever but definately need adjustable reg and readable gauge. BYW, a gauge really means nothing outside your smithy as they fluctuate so widely from one to another and forge designs. YOUR psi won't match mine unless you bought EVERYTHING where I did. But it will help you with repeatability in your own forge.

Edited by Dodge

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For some reason I have to post in tiny one sentence edits. I can't post an entire post in one shot.

Ok so I need something more like this

http://www.amazon.com/Bayou-Classic-Adjustible-Regulator-Assembely/dp/B007PS0938/ref=sr_1_4?ie=UTF8&qid=1403378881&sr=8-4&keywords=high+pressure+propane
Could anyone offer some insight as to how the atlas forge burner works? I feel like it couldn't be that hard to make. It looks like its just the outlet tac welded to a piece of pipe?

Why does that burner function so well without a flare or large air inlets?
burnernew_zpse2a77a79.jpg

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Ok so I don't know where I am going wrong that the burner in the post above works so well. Mine doesn't seem to have the same effect.

 

What do you guys think I need to change?

 

This is my burner.

 

#57 hole. 6" long, 3/4" pipe

 

1111_zps3ba38c1d.jpg

 

I realize it has no flare but I did try it inside of a round tunnel of bricks to try and simulate it being in a forge and it didn't really improve. In the video its probably at around 7 psi. If I crank it up any more the flame starts to become turbulent and pull away from the tip.

 

th_IMG_0670_zpsf4cd329f.jpg

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How does it perform inside the brick? Many good burners only work inside the forge due to lack of back pressure outside the forge

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How does it perform inside the brick? Many good burners only work inside the forge due to lack of back pressure outside the forge

 

Honestly I am not fully certain yet. I haven't cut the real brick to fit inside the forge yet. I put it inside of 3 of the hard style firebricks I had and it didn't improve. But I just kind of had it on a table pointing into the tunnel so I don't really think it would count as a conclusive test.

 

Does everything about its design look like it should work?

 

 

Heres where I am at so far with the actual body.

post-54874-0-81896100-1403808845_thumb.j

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Would I be better served by a square cutout for the forge way or circular?

I assume the circular tunnel would allow Better heat flow but reduce forging space.

The bricks will be 4.5" square. I was going to go with a 2.5" square or hole.

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So I have the actual refractory structure completed.

 

My burner seems to be not how it should. I think I am going to salvage the brass and build a replacement Reil style burner which seems to be the most popular.

 

The issue with my burner is that randomly the flame will shoot out the air holes near the base which is very dangerous and if I turn the pressure up, the flame escapes the tip of the burner and just becomes extremely violent and not any more effecient.

 

 

 

My final question hopefully someone chimes in, what do I do about a flare? Does it need a flare inside of the actual forge? Should I care a flare shape into the refractory where it meets the burner?

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I think someone already said. "Get another Regulator". The one you have won't flow enough to make your burner work properly.

Atmospheric burner requires pressure through the jet, to create a low pressure behind the tip and draw air with it. You either don't have enough pressure or your air orifices are not big enough. You could try using a hair dryer as a fan, but maybe you should figure out what you have first. There is enough information in this site to sink the navy, maybe try using it.

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Today I built the Reil burner following instructions I found.

 

3/4" pipe 8 inches long. #57 hole for the propane.

 

It still isn't getting me that jet flame I see everyone has. What am I doing wrong here? I'm about ready to throw in the towel starting to get pretty bummed over this. Just throwing money away making these burners.

 

This is the new burner from 0-20psi.

 

th_IMG_0711_zps1e482344.jpg

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