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just built my first forge.... so many questions


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As the title states I have just finished building my first forge.  I have tested some 3/16" A36 angle in it as well as 3/4" A36 round bar.  It seems to work but I do have a few questions.  My main question is how do I know if gets hot enough for Forge Welding? I eventually want to make some Damascus. 

First off my forge is a single burner propane forge made out of an old 20lbs propane tank. The front opening is 5"x3".  The burner I made myself from 3/8" black steel with an 0.030" MIG tip. The spec called out the MIG tip threared into a 3/8" brass male spigot which is threaded into a 3/8" black steel coupling. This coupling is secured inside a 3/4" to 1-1/2" reducer.  This design stated that OD of the 3/8" coupler and the ID of the 1-1/2" reducer allowed for enough air flow to be pulled in and an air regulator not required.

I followed this design and have a 0-20psi regulator hooked up on my propane tank.   I have a video I took when I first fired the forge and placed in the 3/16" mild angle. By looking at the video and flames coming out of the opening can anyone advise me if my setup would infact work for forge welding? If not any suggestions to slight modify my setup? 


Turns out my videos are too large.  I will attempt to link them





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2" thick of 6lbs desity firber blanket designed for kilns 2300F rated

30 minutes ago, ThomasPowers said:

How is your forge insulated?  How hot it will get is a balance between heat in and heat out. You have described the heat in part; not tell us about the heat out part.


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The Vids show a LOT of Dragons Breath. For a hotter flame, you'll want more air for the same gas. 

In a Naturally Aspirated burner, the speed of the gas out of the jet (your mig tip) is effectively what draws the gas in. If you make the jet smaller and the gas pressure higher, you'll have more speed out of the gas jet for the same gas flow and you'll draw more air in, giving a hotter flame.

Try a .023" MIG tip and let us know what happens.

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3 hours ago, Irzy said:

The burner I made myself from 3/8" black steel with an 0.030" MIG tip.

If this is accurate then the MIG tip orifice is WAY too big for the diameter of burner tube you are using from what I've seen.  Usually the 0.030 or 0.035 tips are seen for 3/4" tubes.  For that size forge we normally see one or two 3/4" burners, or sometimes two 1/2" burners.

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Your burner is running pretty rich, it should ROAR loudly and produce much less dragon's breath. The orange flame coming out the opening is unburned fuel, commonly called "dragon's breath." This much indicates your burner is running WAY too rich and worse it indicates  your forge is generating WAY too much Carbon Monoxide, (CO) This is a B-A-D thing in and above not producing the heat you need. Read about CO poisoning, it's a insidious odorless, tasteless gas that locks up the hemoglobin in your blood so oxygen can't bind and do what it's supposed to, keep you ALIVE. 

Without telling us the diameter and length of the mixing tube you're using it's hard to recommend tuning steps. Try a smaller dia. mig contact tip is a start. 

Maybe build a different type naturally aspirated burner, there are others that are easier to tune. Check out the Gas burner sub section of the "Gas Forge" sub section of the "Forge" section of Iforge. 

The blanket you are using is a little low temp but can be covered and will work. Check out  the "Forges 101" thread in the gas forge section for methods of building a gas forge that will take the heat, mechanical and chemical conditions in a forge.

More details please, we'll be more than happy to help you get your forge operating like it should.

Frosty The Lucky.

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When you change your burner enough to get a decent flame from it, Your next problem will surface. Your burner isn't aimed where it needs to point; instead of impinging at the near side of the forge floor, it is aimed at the ceramic fiber blanket wall.

Before you try to make any burner changes, please read through Burners 101, or the threads on building "T" burners, to find out how to build a propane burner properly. Then read through Forges 101 to find out how to rebuild your forge.

I looked at the videos, and saw good workmanship in your forge; but you need to listen to the  knowledgeable builders on this forum, and forget about the fantasy advice of self styled 'experts' on YouTube, and others who are repeating half remembered instruction, but are actually clueless.

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1 hour ago, Frosty said:

Frosty thank you for the info.  As for the CO2 this was just a test fire and the forge was inside the garage for only a few minutes.  Any extensive burning is done outside.


My mixing tube is a 3/4" x 6" black steel with a 3/4" to 1" reducer.  I just went out and bought new MIG tips that are smaller as well as a 3/8" to 1/4" reducer with all new 1/4" fittings to allow more air in.  Tonight once the kids go to sleep I'll get to tinker around and try to dial it in and get more torch less dragons breath

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It looks a little better but it's still running rich. These burners are not quiet it should sound more like a jet engine up close than a loud whisper. 

A 1" x 3/4" bell reducer for the intake is WAY too small for a linear burner. Try a 3/4" x 2" or 2 1/2" bell reducer. 

With a 1" air intake the big elbow you're using for the jet mount is blocking intake air significantly.

I'm not a linear burner guy so I don't know what to suggest as an alternative but I sure wouldn't use the elbow. 

Mike? (That's the sound of Frosty calling someone with more experience with linear burners.)

However, if you want a set of linear type burner plans that work, have decades of proven performance, do a web search for Ron Reil and see if you can find his plans. I think Abana still has them or links.

I have illustrated plans for the T burner posted here. Mike Porter (the Mike I gave a shout out to) published a book about burners some years ago and pirated copies are available online, he'll link you himself.

Frosty The Lucky.


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I do have at my house an electric blower (for winterizing the pool pipes)... 3.0 hp 120-volt three-stage bypass motor with long life brushes, producing 130 cubic feet per minute open flow and 160 inches of sealed pressure.

If I right this up to it, Would this be too much air?

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