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Dustin Stephens

Building a propane forge.... Help, I dont want to blow myself up!

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I drilled and tapped a hole like that that thinking I would need it, but I'm still trying to get MORE air, not less. I hope to eventually need to reduce my incoming air, because then I really can try to control it and be efficient. Right now I can play with my pressure and needle valve to get flow changes. I worry that my needle valve is a bit of an unknown restriction and the pipe between the valve and the MIG tip causes something other than what I think is going on based on my regulator setting. More playing needs to be done for sure, but I can weld and heat treat, so it is just a matter of fuel consumption for me.

 

 

I'm still kind of in a 'well, it works!' zone right now. I spent a bit of time tonight adjusting my injection nozzle placement, and I've come to the conclusion it needs to be lower than it can currently reach (ala the other thread in this forum).

 

 

Chris I apologise for not getting the size right on that tee fitting. Should have checked. You could do a quick trial choke and see if it improves the heat just by using a piece of duct tape to cover part of the intake hole.

No need to apologize!! And I actually did that tonight as well on the choke thing. The differences were negligible, and as Jerrod says, the thing seems to want more air, not less. I'm actually going to order a pair of those wyes and redo the burner bodies. May as well do it the best way possible to begin with, and the wye is going to disrupt air flow a LOT less than a tee.

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I've been considering a forge rebuild for a while now, and I've been tempted to convert to venturi. The problem I have to consider is elevation. I live at 7000' up in the mountains of Northeast AZ, and I worry that a venturi just won't suck enough air into the system for the kind of heat I want. I see these guys with air control valves on their burners and idly wonder what it must be like to have that much air available.

 

Nice to see some guys from Arizona on here.

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Well, I checked my setup (and actually forged for a couple hours) this weekend. Turns out I did move my tip to be at the end of the smaller pipe already, but it was off center a little. I corrected the concentricity of everything and replaced my 12" of pipe with a union for 12" of pipe without a union. No real change in the amount of flame coming from the forge though. But it got plenty hot (no forge welding this time, but the forge does get hot enough for it) so I think it will just be a "some day when I don't feel like forging more than I feel like tinkering" kind of project.

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supplyhouse.com has 1 1/4 black iron wye strainers for $19.00. Dont know if that is cheap or not but they have them.

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Maybe for more air, use a larger wye?

It's just seems kind of weird to me because the NC Tools forge I have has very small intake holes for the air and I get a very hot burn.

NC Tools Forge (2).JPG

NC Tools Forge (3).JPG

Edited by Joshua States

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I actually made some adjustments on mine, including lowering the injection nozzle down into the burner tube, and using a piece of magnetic sheet I had laying around for a choke lol. Definitely some welcome differences in tunability, and it seems to run better at all pressures now. It would sometimes stall, but I'm sure that will go away once I get used to where the choke needs to be for various psi settings.

Here's a short video I took at 2-3psi right after I lit it tonight:

 

https://www.instagram.com/p/BBRSuv4GOlF

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Much better looking flame.

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I actually made some adjustments on mine, including lowering the injection nozzle down into the burner tube, and using a piece of magnetic sheet I had laying around for a choke lol. Definitely some welcome differences in tunability, and it seems to run better at all pressures now. It would sometimes stall, but I'm sure that will go away once I get used to where the choke needs to be for various psi settings.

 

Here's a short video I took at 2-3psi right after I lit it tonight:

 

https://www.instagram.com/p/BBRSuv4GOlF

That is a lot like mine looks. I would prefer to see a lot less flame coming out of the forge, but it definitely does get the job done and oh so much less scale than when you have too much air.

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Well, remember too brother, my burner is about 3-4" from the door right now, and pointed straight down for heat treating lol. I think with a single burner placed tangent and in the middle, it would work pretty well.

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Totally, and mine is at the bottom of a vertical forge. That is why I'm not overly impressed with how mine is working out (again, just from a fuel efficiency stand-point). I guess I should have been a bit clearer on that.

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I still don't get it. The air intake holes on our NC forge are very small and the flame is pretty compact (running at 5 psi in the photo above) with a nice blue/white flame.

Maybe it has something to do with the propane jet alignment going straight through the center of the air intake rather than perpendicular to the air intake?

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Maybe it has something to do with the propane jet alignment going straight through the center of the air intake rather than perpendicular to the air intake?

That does indeed play a role. As does hole geometry (size and shape), total gas volume, orifice size, gas speed (a function of orifice size and pressure), and back-pressure in the forge. I'm sure there are even more variables too.

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So I'm off to the races Edited by Dustin Stephens

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Where should I get my regulator? I want one with a gauge

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To coin a rather annoying friend --- The regulator gettin' place! I was planning on purchasing mine from the local gas company -- but this is a good question id like to know the answer to as well :P

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Where should I get my regulator? I want one with a gauge

Any local welding supply shop should be able to get you one. Mine had a rebuilt one real cheap (about half price) that I got, but they also sell new ones. Having ran a forced air system with just a BBQ regulator for a while, I can assure you that even a nice new one is well worth the price. BTW, mine is a 0-60 psi, but I would have definitely preferred a 0-30 psi range.

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High Temperature Tools and Refractory carries the whole assembly of regulatory, valves, gauge, hose. Everything you need between the tank and the burner.

 

Doug

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So after looking at my burner design, I think I want to redesign it. By doing so I think I will improve air flow. Instead of a 1 1/4 x 1 1/4 x 1 1/4 tee, Im going to replace it with a 1 1/4 x 1 1/4 x 3/4 tee and reduce the 1" burner tube to a 3/4" burner tube. Thoughts??

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So after looking at my burner design, I think I want to redesign it. By doing so I think I will improve air flow. Instead of a 1 1/4 x 1 1/4 x 1 1/4 tee, Im going to replace it with a 1 1/4 x 1 1/4 x 3/4 tee and reduce the 1" burner tube to a 3/4" burner tube. Thoughts??

 

I'm assuming you mean 1 1/4 x 3/4 x 1 1/4? If so, that's how mine is...only it's actually 1 1/4 x 1 x 1 1/4, because my supplier didn't have the x 3/4 ones. I just reduced down to the 3/4 burner tube by using a 1" close nipple, dremeling out the seam, and 'threading a 3/4" burner tube into it. I figured this would be less of a transition than using a reducer.

 

It's working great.

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Yeah thats what I meant. Also the 3/4 burner tube allows me to get one of the zoeller type stainless burner flares. How far does the end of the burner need to protrude into the forge cavity?

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