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Forge makes popping and or whistling sound,  what will cause this? Thanks for any help!  Two 3/4" burners .023 mig tip for propane output, 690.cubic inches of volume in chamber.

Edited by Charlir Jack
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Your burners are whistling?

Seeing any flames coming back into the burner?

What set up is the air intake? (Such as “T” burners, or rectangular holes or circular holes in the burner?)

 

Gary LT

Edited by Gary LT
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Yes some small flames, my air intake is 3/4"×1 1/2"  reducing bell black iron gas fittings, sounds more like a pop and whistle mix, kind of like a venturi setup, i think.

Edited by Charlie Jack
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Yes, I am familiar with the bell reducer and used it before. I didn’t ask how long the 3/4” burner tubes were....or what PSI you’re running (if you know?)....here’s why....

23 mig tip is the smallest orifice tip and has significant velocity. As gas is expelled, it pulls air thru the tube as well thereby getting a good mix to add oxygen and burn at the burner tube end which is inside the forge.

But too much velocity and the burn is erratic and moves back and forth, hard to adjust.

I had to lengthen my burner tube to accommodate such an erratic burn on one set up. 

On another, I went with a larger size mig tip .030 or .035 for more gas, less velocity than the .023, but a better mix in the tube so I could get a controlled burn at the tube end in the forge.

Also your forge cannot be completely closed off. Like sealing off the front opening to retain heat. Some heated air has to escape to equalize the pressure inside for a Venturi to work.

There are just a few things you may want to look at, one step at a time, easiest first.

Just based on some of my experience which worked and I am no “pro”!

 

Kind regards, 

Gary LT

 

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2 hours ago, Charlie Jack said:

Yes some small flames, my air intake is 3/4"×1 1/2"  reducing bell black iron gas fittings, sounds more like a pop and whistle mix, kind of like a venturi setup, i think.

10" burners 2.5 psi, air intake is 1 1/4 " not 1 1/2" with 4, 1/4" set screws to brass caps tapped for 0.023tip. Do i need to be able to control my air intake?

0425201624a-1.jpg

Edited by Charlie Jack
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Well, have you increased the PSI, 2.5 is economical but does whistling and backup flaming stop by increasing the PSI in stages, (5, 8, 10) what is happening at the burner tube ends? Blue flame or is the blue flame dancing away from the burner end? 

Gary LT

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27 minutes ago, Gary LT said:

Well, have you increased the PSI, 2.5 is economical but does whistling and backup flaming stop by increasing the PSI in stages, (5, 8, 10) what is happening at the burner tube ends? Blue flame or is the blue flame dancing away from the burner end? 

Gary LT

Blue flame is there and it doesn't dance around, or away, i have tried higher pressure just not in stages. Could my flares or, my 2" burner tube holders cause it, my flares do not fit tight inside the liner could this be part of my problem?

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There are other variables Charlie, a) how far the mig tip is positioned into the tube (or the bell), b) are they centered, c) does it start whistling or backfiring after the forge is hot? (Your pipes are vertical over the heat), etc.

A ten inch burner, (longer yet with flare on the end), should be plenty long enough using a .023,  can’t say because mine were not that long. 

 

Try what I suggested first.

Gary LT

 

Edited by Gary LT
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Mig tips 1 1/2" in bell ,yes centered, after it gets hot, yes vertical, I opened up the back exhaust more and raised my pressure to 5 psi that seemed to work this morning, thank you for your knowledge and help , i will run my forge like that and see what it does . Thanks again for your help!

1 hour ago, Gary LT said:

There are other variables Charlie, a) how far the mig tip is positioned into the tube (or the bell), b) are they centered, c) does it start whistling or backfiring after the forge is hot? (Your pipes are vertical over the heat), etc.

A ten inch burner, (longer yet with flare on the end), should be plenty long enough using a .023,  can’t say because mine were not that long. 

 

Try what I suggested first.

GaryLT

 

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Good then.! I never had an issue with vertical pipes but some have stated so.

Happy forging now!

 

Gary LT

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Something to take note of, I built my first burner like that too. With those mig tips so far down the bell, and so much of the area around the bell being taken up by the delivery system you have built there.  You are really restricting air flow, and your not able to maximize your venturi effect. The best place for that mig orifice to be is 1/8in down inside the big opening of the bell.

 

If you can get that to work to your liking that is fine, I'll try to find a link to my build where I made a small bracket that held the plumbing outside that bell reducer. I notice I could run with a little lower pressure once I did that, but 5psi is about standard. 

 

 

https://www.bladesmithsforum.com/index.php?/topic/37612-psssst-newbie-wanna-build-a-propane-forge/

 

Go through that post, the link to my build is the second from the last where I did just about the same build.

Edited by Daniel W
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Whistling is irritating, but popping is bad.  That sound is usually a result of the flame front burning back faster than the fuel gas delivery at the burner outlet (flare, in your case).  This results in the flame moving back into the burner tube, heating it and preigniting before it exits that tube.  There are several typical solutions, but they amount to two general fixes:  increase the amount of fuel/air that exits your burner (increase gas pressure and entrain more air, open that air entry point by removing some obstructing fittings, change your mig tip location to improve the ventauri effect...) or reduce the size of your burner outlet flare.  The latter will limit the maximum heat you can produce with the burner, so you are probably on the right path with your current solution.

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On 4/28/2020 at 9:44 AM, Dan Hertzson said:

Whistling is irritating, but popping is bad.  That sound is usually a result of the flame front burning back faster than the fuel gas delivery at the burner outlet (flare, in your case).  This results in the flame moving back into the burner tube, heating it and preigniting before it exits that tube.  There are several typical solutions, but they amount to two general fixes:  increase the amount of fuel/air that exits your burner (increase gas pressure and entrain more air, open that air entry point by removing some obstructing fittings, change your mig tip location to improve the ventauri effect...) or reduce the size of your burner outlet flare.  The latter will limit the maximum heat you can produce with the burner, so you are probably on the right path with your current solution.

Thanks everyone for all the info it has been a great deal of insight and knowledge that i lack as a newbie to forging, i will post my results when i get the t burners done.  Thanks 

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