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Jlinner

Burner Placement

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Hello All,

So when building a round type forge lets say out of a air tank or a propane tank, why do I see some builds with the burners at 10 or 2 o'clock on the forge?

What is the benefit of this placement vs. at noon straight up and down?

Thanks in advance,

John

Edited by Jlinner

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You do not want the flame directly hitting your metal or your refractory.  This could lead to excessive wear from the flame impingement.  In your metal it will mean a tendency to decarburize the metal (and form form scale), with the refractory it will cause it to break down faster.  Applicable to both metal and refractory, it creates a hot spot if not angled.  The angle is meant to cause a swirling action that distributes heat more evenly.  

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Ahhh, ok a swirling action... I get it. Thank you Jerrod.

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well, I have forges that have a little swirl and some that have a burner coming into the forge with no swirl . I cant say its at all important to me and my work. my main  use forge has a burner directly  that is pointing directly onto the steel.......

 as with most things there is no one answer.

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Like with so many things, "better" can be quite relative.  If the swirl improves refractory life by <1%, it is better, but to a pretty negligible level.  If you WANT a hot spot (and there are applications where that may be quite useful, depending on size, placement, and oxidizing factor), you don't want the swirl.  

Another thing that is vaguely related: the inlet pipe often comes in at an angle to the forge relative to the ground (not necessarily to the forge) because propane is heavier than air, thus you don't want it to run backwards into your fan.  At the same time you don't necessarily want it straight up, because heat rises and you don't generally want your plumbing getting hot from the radiant heat coming from the forge after you shut it down.  

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a buddy did a propain forge from an old tank and used the original outlet to screw his burner in well once it got hot it would run for shit as it was a ventury and was sucking all the exost fumes in the burner made a baffle over the rear door and its not as bad now

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2 hours ago, dragoncutlery said:

a buddy did a propain forge from an old tank and used the original outlet to screw his burner in well once it got hot it would run for shit as it was a ventury and was sucking all the exost fumes in the burner made a baffle over the rear door and its not as bad now

Sorry, let me try to understand. Did you mean: He used the original valve hole to thread the burner into. It wouldn't run for $#!7 once it was hot, because it was sucking all the exhaust fumes into the burner? Was the burner choke outside of the forge? I just don't understand how that much exhaust was reaching the burner.

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hot air rises and he built the forge with the tank setting normal with a direct down flow burner and as it was a ventury it would suck the already burnt gases in and try and re-burn and that doesn't work so well

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So a vertical forge with the burner vertical on top?  Yeah, not a great idea.

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check out the Build a Gas Forge attachment at www.WayneCoeArtistBlacksmith.com

Let me know if I can help you.

Wayne

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On 11/16/2017 at 11:06 AM, Alan Longmire said:

So a vertical forge with the burner vertical on top?  Yeah, not a great idea.

The art of understatement is practiced here

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Ok, so NO vertical burner position. Thanks guys!

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On 11/15/2017 at 3:13 PM, owen bush said:

well, I have forges that have a little swirl and some that have a burner coming into the forge with no swirl . I cant say its at all important to me and my work. my main  use forge has a burner directly  that is pointing directly onto the steel.......

 as with most things there is no one answer.

 I like the ability to work in and out of the hot spot in the center. Not a fan of swirl forges. 

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1 hour ago, Sam Salvati said:

 I like the ability to work in and out of the hot spot in the center. Not a fan of swirl forges. 

When I switched from solid fuel forges and first got my Chili forge I remember searching with the steel wondering "where's the &^%%% hot spot?" . I don't miss it now but it took a bit of adjustment on my part.

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47 minutes ago, Vern Wimmer said:

When I switched from solid fuel forges and first got my Chili forge I remember searching with the steel wondering "where's the &^%%% hot spot?" . I don't miss it now but it took a bit of adjustment on my part.

So you have a no swirl and like it?

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2 hours ago, Sam Salvati said:

 I like the ability to work in and out of the hot spot in the center. Not a fan of swirl forges.

Is this hard on your equipment or any issues at all?

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Even with a swirl you still have a hot spot.  It's just up on the side so you have to hold the steel up into it.  I like a swirl myself, but it is nice to know where the hot spot is when you need it.

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Can you guys post up some pics of swirl type forges?

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17 minutes ago, Jlinner said:

So you have a no swirl and like it?

No, I do have swirl and I prefer it, after I got used to it. It is all about personal preference and style/method of work. To go overboard answering I'll explain my reasoning. Like others mention I get less scale and since, now, most of my steel is "new" I focus less on getting salvaged/mystery steel "into the proper shape to start making a blade" . I don't need to focus heat on one spot to straighten it out or make it flat, so I want the piece uniformly heated so all of the piece is available to be "struck" where needed when it comes out of the forge. Of course this is in consideration of the fact that I don't do very long blades, forge weld, and such very often. Others may have very good reasons for a different choice based on what, and how, they do things. It's all relative.

Added after reading Alan's post. There will always be a hot spot if you want ti find it, I just rarely find a need for it, besides, I forgot to mention that my forge is my heat treating tool and I want a more even heat with no hot spots for that.

Edited by Vern Wimmer
Coffee defficiency

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3 minutes ago, Vern Wimmer said:

No, I do have swirl and I prefer it, after I got used to it. It is all about personal preference and style/method of work. To go overboard answering I'll explain my reasoning. Like others mention I get less scale and since, now, most of my steel is "new" I focus less on getting salvaged/mystery steel "into the proper shape to start making a blade" . I don't need to focus heat on one spot to straighten it out ir make it flat, so I want the piece uniformly heated so all of the piece is available to be "struck" where needed when it comes out of the forge. Of course this is in consideration of the fact that I don't do very long blades, forge weld, and such very often. Others may have very good reasons for a different choice based on what, and how, they do things. It's all relative.

Thank you Vern.

 

Also, direct heat helps in the forge welding process as well?

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2 minutes ago, Jlinner said:

Thank you Vern.

 

Also, direct heat helps in the forge welding process as well?

Check my edit to last post.

I know it does for blacksmith type forge welding but don't know about billet making for blades.

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2 minutes ago, Vern Wimmer said:

Check my edit to last post.

I know it does for blacksmith type forge welding but don't know about billet making for blades.

I got you, thanks again Vern.

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On 11/15/2017 at 11:44 AM, Jerrod Miller said:

Applicable to both metal and refractory, it creates a hot spot if not angled.  The angle is meant to cause a swirling action that distributes heat more evenly.  

To clarify a little on what I meant here and as mentioned above:  Your burner can always be used to locally add heat, and you can choose to point that burner basically wherever you want.  If you point it straight at the floor, it becomes more difficult to miss the hot spot, if you point it tangentially along the ceiling you have to actively put your work into the flame path.  Coming in at a tangent spreads out the flame impingement on your refractory.  If you always want to use a hot spot but don't want to be blasting your refractory directly, you can have the burning come in on a tangent at the bottom.  My general purpose forge is a vertical pipe forge, so I operate well away from the direct hit of the burner.  

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Here you go.  Uses two sidearm burners and made from an old propane tank.  I brick up the back and parts of the front to contain the heat.  It gets to welding heat.  This after just a few minutes of running and not all the way up to heat...

 

 

Edited by Wes Detrick

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At the risk of sounding like an idiot, why arent burners mounted on the bottom? will it have back pressure problems? It seems to me since heat rises it could be more efficient plus you don't have to worry about the chimney effect. Also you dont have to worry about your hoses dragging the forge body, or hanging above it drying that rubber out. 

On a separate note, would it be a terrible idea to make a very small one burner gas forge just for forge welding damasscus billets? i have never done actual pattern welding, but I feel that I'm ready and my tools are not. I apologize for being off topic.

Edited by Zeb Camper

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