forge building question

ScottRoush

ScottRoush

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Jan 10, 2010
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I'm building my venturi side arm burner forge and I have a very basic question... Do you make an opening through the ceramic wool for the burner flame? I know that the flare for the burner is to remain within the confines of the ceramic wool.. but is there an opening for flame? I realize that the heat is supposed to vortex through wool around the working environment... so I'm assuming that there would be no opening... But I just wanna make sure.
 
The flame does not travel through the wool. The wool is an insulative layer to keep the swirling flame's heat inside the chamber and prevent it from radiating out through the forge body. Yes, you HAVE to have a hole in the blanket for the flame to pass through and into the forge chamber.

p.s. Dont' forget to line the blanket with something (satanite, ITC, etc). This stabilizes the blanket to make it more robust as well as prevents you from significantly shortening your life span because of silicosis.

--nathan
 
I've never worked with ceramic wool but I can almost guarantee you it's supposed to have a hole through it the width of the burner. I couldn't imagine trying to light a burner through ceramic wool, and if you did it would likley restrict air intake. the real problem is when your burner tube extends down into the forge.
 
The burner tube should extend about 1/2" beyond any lining material. Make your burner tube adjustable so you can slide it in and out to find the sweet spot. It also needs to be slightly angled so the the flame swirls. This is based upon my recent build.

Milt
 
ughhh... okay... Yeah... you have to light the burner. :o

The confusion I'm having might be coming from something I read in the '$50 Knife Book' about how the heat swirls through the wool and radiates through interior surface rather than direct heat by the flame itself. This was written about the little coffee can type forge with Bernzomatic...

And here is what is written on Zoeller's site:

When installing burner assembly in the forge the flare should not extend down into the forge chamber it should be up inside the Durablanket about a 1" to help protect the flare from the high heat in the forge chamber
 
The "flare" in that case is the expanded portion of the burner at the output end, the "nozzle", if you will.
 
Basically, there has to be an opening in the wool. Here's what I do: I cut the kaowool to fit first, fit it into the forge, take a fine point sharpie and insert it into the burner tube aperture in the side of the forge, mark a circle carefully. I carefully take the wool back out, and using a thin blade (snap type) razor knife, cut the hole out undersized. I then (wearing gloves) mold the wool by hand, stretching and compacting it to match the diameter of the end of the burner tube. I think this makes the opening fit more tightly and be more durable. Usually I build a forge with two layers of 1" Kaowool, using this process both times. After finally installing the wool, I run the burner tube down into the forge an inch, leaving the innermost hole/layer of Kaowool as an extension, if you will, of the flare (or plain tube without flare). That way the tip of the burner tube/flare won't overheat nearly as bad. I make sure by hand that the kaowool fits the flare with a nice round opening, then mix up my satanite or ITC, apply it to the inner surface of the forge chamber, then apply by hand, WITH GLOVES, to the inside of the 1" opening in the wool at the tube. That way it makes a smooth, protected extension of the burner tube. The smoother (and preferably with a little flare) you can make this, the nicer your flame will be, and even your fuel efficiency may improve. For tips on venturi burner forge construction, check this link out:
http://ronreil.abana.org/sitemap.html
Very indepth discussion of design there.
Hope this helps.
 
Thanks a lot Salem... That's what I've been looking for. I have all the hardware and I just welded my burner tube holder onto the tank. So I now just need to put it all together.

Very helpful... Thanks again.
 
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