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I Forge Iron

Designs for a gas forge

Matt Smith

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Currently I use a coal forge but down the road I would like to build a gas forge I have been looking at diffrent designs and I am intrestedn in building a forge mostly for blade smithing but I would one day like to try my hand at swords. I do not have axxess to a welder so I was wondering if any body has any plans or good how- to's to build a good gas forge which can be used for blade smithing, that can get up to forge welding temp ,that can be built without the need of welding it together. I have viewed several designs such as useing paint cans, old propane tanks, etc with high temp furnace wool and refactory coatings with various burner types... Im looking for advice and or instructions on a good realitivly simple design that is affordable to build. Thanks for any help or suggestions

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Hi, brand new to the site, but I just finished building a forge that may be just what you're looking for.

Check out http://zoellerforge.com/firebrickforge.html for step by step instructions.

Although the plans talk about welding the top piece, you can substitute perforated angle and avoid the welding.

Total cost was under $75. I used insulating rather than refractory bricks because they were easy to get locally, but the forge heats really well, and you can craft different brick sizes to control het loss from the back end.

Good luck!


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I built 4 of these for my gas forge, and they work great:


I added chokes to my burners, to allow adjusting the flame to neutral or reducing, like the foreground burner in this photo:


You should probably read all of Ron Reil's web site. All your questions about gas forge construction will be answered, but not always spoon fed to you... you'll have to think and spend time trying out some stuff on your own. It's a great way to pass a Saturday afternoon. As soon as you make your first working burner, you'll get all kinds of ideas for things you'll want to try on the next one, and so on. Pretty soon you'll be able to make a burner from random parts you have lying around.


The hardest part (at last for me) was making the tapered nozzles. One method is to heat up a piece of pipe to forging temperature, and then forge out the taper with hammer and anvil. It was a bit of a cach 22 for me, because I was building the burners to be able to forge in the first place! I ended up making a really crude & ugly, but functional enough, burner nozzle, which I used in the forge body I had already built to make 4 nicer nozzles.

Since then, I have managed to acquire a 7x12 mini-lathe, and have found that it's easy to make very nice tapered nozzles from straight 3/4" black iron pipe couplings. The advantage with a mini-lathe is you can bore out beautiful tapers at exactly the required 1:12 slope. Then you can use the remaining threaded end of the coupling to attached your nozzles to the business end of your burner. This is stronger than using set screws to fix the nozzle in place, but requires changing Reil's design a bit because you have to leave on both threaded ends on your 3/4" pipe nipple.

Best of success!

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Check this video out. It shows how to build a simple burner. Also, late in the video, it shows the use of a home built forge that allows access to the burn chamber from one to three sides....

Good luck with your adventure...


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Ok I have another question afte I get the burner set up I know Ill have to hook up to propane source via hoses conectors regulator etc... my question is can I get a adjustable propane burner that is used for like turky fryer or grills that are adjustable from 0 to 30psi....or do I have to buy the more pricey regulators such as those sold on zellerforge website and others.I ask because I want to keep te buld cost as low as I can. Thanks yet again for any help

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Consistency over long periods of time is important.. but don't stress it. I bought a low-mid range regulator and needle valve to control flow and pressure. As pressure and temperature in the tank changes it may slightly change the consistency of your regulator but it'll be negligible unless you want extreme and exact control with in a few degrees is it worth paying twice as much?

If money is no obstacle consider investing in a good pressure gauge over an expensive regulator. They less expensive than a high end regulator and more useful for documentation. I would check your local gas supplier over buying online or in a home improvement store. They'll be able to help you out with fitting and everything else. The cost is often fair.. if not the cheapest.

Flow is as important as pressure in my opinion so if you haven't consider the needle valve. High pressure and low flow may be needed for a small forge with a long burner tube, for instance.

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  • 9 months later...


I have a question. I used this great video to make the burner for the forge i'm building now. I have everything in the gas line except for the needle valve. Would it be safe to start using it with just the regulator and shutoff valve until i was able to get the needle valve? Or should I just wait? 

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  • 1 month later...

I built this one and it works great. I have nothing to compare it with though since it is my first and only burner at this point. I would say the needle valve makes all the difference. If you are using the adjustable regulater he recommends I guess  you could do it with that but I don't know how difficult that would be. It would not allow the very small adjustments that are needed, at least not as easily. I run my regulator wide open. The needle valve at about 5 for start up, then after a couple minutes open it up to 7. ROAR. I think a good thing about this burner is that it is forgiving, meaning you have several points of adjustment and tweaking so being perfect on the build is not a requirement. One difference I have on mine is that he chokes his with kaowool completely. I only choke it about half, otherwise I dont get the burn. Choke meaning where he stuffs kaowool in the top of the mount tube around the burner tube. Another is that I use a wire feed tip instead of a mig tip. Maybe they are the same thing though I dont think so. It's all they had at the store. Got my needle valve on ebay for about $25.00. I have a picture of my forge fired up under my profile.

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In my opinion, air (blown) gas forges are the way to go. Comes down to piping , a blower, a needle valve regulator and your own creativity. The units reach welding temp fast, consistently and they are easy to build. In comparison, we have an old NC tool forge in the shop that works well enough for quick heats but it doesn't really get up to welding temp and the interiors degrade quickly when in use. The plus side on these Venturi rigs is that the expense to manufacture is low and they are not too heavy.

The design choices for you the builder include, shell materials and insulating media. Also any auxiliary fittings you may want to add The media can be solid castable or fiber layering depending on your preferences in regard weight and portability.

A few fellows on IFI have great forced air forged designs and there are plans available. This way you can get ideas on size and materials. I believe the New England Blacksmiths have planes for a good heavy duty solid castable blown forge that will last a lifetime . The point of contact is the Ball and Chain Forge ( Bob Manard), Portland Maine. NEBA has a meet coming up in Sept at their facility in Brentwood, NH. They may have one there you can check out.

A good serviceable forge is critical to your shop. Don't spare the research, that way you will get what you need and only have to build it once. Good luck with the project.


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