forge burner blues...

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Nov 29, 2000
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So I've built, redone several forges but in resurrecting this one, I find that the burners don't burn evenly. I've tried/looked at any possibility here and can't see what I'm missing. Here's a little vid of a test firing and of course, without back pressure it's hard to see how they will work in the forge but I didn't have time this morning. everything is the same on both sides, and the pipe fittings/migs tips free from any restrictions. Still they don't burn/fire evenly! And, I'm wondering if I can get weld heat from these two or, if I'll need to go back to a three burner setup.


https://www.youtube.com/watch?v=ISS2IItDP90&feature=youtu.be

tia, mitch
 
So Atlas, does that look like a good flame? enough for welding heat in the right space/environment? I've used HTC-100 on the interior of this forge.
 
I couldn't see the flare. Do you have one? If so maybe it needs to be bigger.
 
To be honest, it looks like a small flame for that size forge. I'm thinking it's around the same size as my 30K BTU burners, and I would estimate that you want at least 120K total for that forge. Do you have any idea of the orifice size? If it's .023", then you should probably go with .035". If it's already .035, then something else might be wrong, possible with the regulator. Do you have another burner you can test to compare it to?
 
If they don't behave the same, it's fair to assume something is different. Possibly several somethings. It helps to be systematic when fault-finding and to only change one thing at a time.

Personally, I'd swap the gas jets between the burners first (I'm assuming you are using MIG tips for gas jets) and see if the imbalance follows the jet.

If it makes no difference, try swapping the flares next (I'm assuming the flares are not fixed: you seemed to be adjusting their position in the video).

Do all your initial looking for the differences with the chokes fully open to take them out of the equation.

My feeling with burners is that, ideally, you want to get close to an all-primary-air flame (almost all hard central cone with minimal bushy outer flame) with the chokes fully open, giving the highest flame temperature. Then you can adjust the flame temperature down (and make the forge atmosphere more reducing) by closing the chokes.

It's important to understand that the choke adjustment varies the temperature of the flame, whilst the pressure adjustment varies how much of the flame there is.

For mid-range temperatures, you can usually get the forge temperature required either with a lot of relatively cool flame, or with a little relatively hot flame. Many people focus on gas consumption and try to run with the small, hot flame. Others focus more on the scale and decarb situation and tend to accept a higher gas consumption as the price they pay for a reducing forge atmosphere. These guys run a bigger, cooler flame.

For welding, you usually need quite a lot of very hot flame and do not really have as much choice over settings.
 
All your problems and the solutions given are why a blown burner is simpler and better. You can adjust the flame from a whisper to a roar in seconds ... and maintain the desired atmosphere. I think a blown forge is much better in a welding forge. Others may have different opinions.
 
All your problems and the solutions given are why a blown burner is simpler and better. You can adjust the flame from a whisper to a roar in seconds ... and maintain the desired atmosphere. I think a blown forge is much better in a welding forge. Others may have different opinions.

Great... have a plan/tutorial on how to build one?

edit: found this...

http://www.bladeforums.com/forums/showthread.php/424799-Fogg-designed-Norris-built-forge-at-Ashokan-2006

but I can't tell what diameter the shell is. Looks like 14" casing to me.
 
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