Burners 101

[Mikey98118]

      Making do

       Below is one step in constructing a 1/2" burner made from a schedule #10 stainless steel pipe for its mixing tube. Using schedule ten instead of schedule forty pipe gave several advantages, and one disadvantage in fitting up an end cap. There was an alternate method provided for people without a drill press. Why? Becuase you shouldn't need to have a steel shop to do some blacksmithing.      

      The end cap is a 1” long 0.750" O.D. brass round bar. You will need to drill a center hole for the gas pipe with a letter “Y” drill bit, and then power sand, or turn about 0.040”  from the cap’s outside diameter to press fit the cap into the end of the mixing tube. Then drill and a tap 10-32 hole through the mixing tube and through one side of the cap for the last 3/8” long stainless steel socket set screw (part 8), which traps the gas tube and MIG tip in position: Part #1266 at Onlinemetals.com; cut to 1” length; this part costs $1.67 plus shipping (enter “1” in the popup cutting window).

 

 Alternate method: If you don’t have access to a drill press, You can use a 1” long section of  schedule #40 brass pipe; its OD is 0.680” and its ID is 0.500” (part #1574 at Onlinemetals.com); its cost is $1.51 and shipping when cut to 1” length.

    Since both the tube’s outside and inside diameters are undersized, you must use tape to hold the pipe centered in place, while you drill and thread six 10-32 by 3/8” long socket head set screws through the mixing tube and through this part. The screws are drilled and threaded one at a time, as two rows of three equally spaced screws. The screws are to be screwed into position and left there permanently as each threaded hole is created; otherwise the parts can drift during the process, ruining all your work.

    Next, the gas tube is taped, so that it will sit snugly centered within the brass tube, and all six screws are screwed further in until they just touch the tape. Withdraw the gas tube, remove its tape, and reinsert the tube, taking a partial turn on each screw until they barely touch the gas tube; this should keep it sufficiently centered while you tune the burner. Once tuning is done, lightly tighten the screws.

This same technique can be used to make an end run around a lack of the right available sizes when fitting up flame retention nozzles too.

[u_p_country]

Good morning all,

Looking for some tuning advice on a couple burners I think I'm in the ball park but want to get closer to the ideal.

Pic 1 - 3/4" Burner #1 uses a .035 mig tip in a schedule 1/8" #80 gas tube 4" long.  Pressure in this picture is 8 psi. Nozzle is the stepped design from Mikes book.

Pic 2 is the full burner

Pic 3 - 3/4" Mikey Burner uses a .030 mig tip in a schedule 1/8" #80 gas tube 4" long.  Pressure in this picture is 8 psi. Nozzle is a stepped design with a thread protector instead of smooth wall tube. I intend to chage this for the regular nozzle when materials arrive.

Pic 4 is the full burner

 

I'm relatively new to all this but eager to learn!  Reading on this forum has been mind bending!

[Another FrankenBurner]

Burner 1 reminds me of a Z burner by Larry Zoeller.  

One thing to pay attention to is what you are seeing with your eyes.  All of the advice given here will be based on the pictures and the camera can skew the flame enough to look completely different then it is in reality.  I have also noticed that depending on the ambient lighting, the flame can present itself completely differently. 

Mikey has been good about explaining reading the flame.  It is the most important thing I have learned, from this forum, when it comes to tinkering with burners.  We almost need a Flame 101 pdf on the forum.  Without knowing what you are looking at or for, how can you tune a burner?

That said, many varieties of flame are useful and desirable.  Many people prefer a reducing/rich flame as a means to limit scale production.  This conversation is explaining a neutral flame and not a flame you have to achieve.  A lot of burners are not capable of it.  My main forge runs a flame which is very rich and it still gets the job done at a cost of fuel.

Lets focus on the first picture.  It looks to be running rich(according to the picture).  It shows 4 clearly separate zones and so it is a nice picture to talk about.

Zone 1 is what a lot of people call the secondary or tertiary flame.  I like tertiary flame because secondary gets confusing, you will see why in a minute.  Anyway, we want as little of this as possible.  None visible, in a perfect world. 

Zone 2 is sometimes referred to as the primary or secondary envelope.  Take a good look at it's color because that is what you want the entire flame to look like in a perfect world.  It is the flame which is mixed and burning properly.  

Zone 3 is sometimes referred to as the primary or secondary envelope.  It has a green quality to it.  This is an indication of a rich flame.  In the perfect world flame, zone 2 and zone 3 will be one zone of a uniform color.

Zone 4, I'm not sure what it is referenced as.  We want him to look hollow or void.  Transparent.  

Here is the best example picture I have:

If the flame goes dark blue or even to levels of purple, it is oxidizing:

Now hopefully Mikey will chime in and add details.

[Mikey98118]

The easiest thing you can do is start by changing out your MIG tip. If that is a 3/4" burner size, it should be running a MIG welding tip for .025" welding wire. When I wrote the book they didn't exist, but they do now. If you can't find one easily, you can choose from between using a set of torch tip cleaners to enlarge a tip for .023" welding wire another three thousandths of an inch, or running a tip for .030" weld wire, which is a little large, but will work good enough to get by. When you have time and a little money, You could buy a rotary tool and a diamond encrusted burr and turn those air slots into something closer to rectangles. Then, bevel their forward and rear edges to increase air flow.

You haven't committed any big mistakes, so much as you need to finish the burner

[Mikey98118]

After the tip change your flame retention nozzle will respond much better to changes in its distance beyond the end of the mixing tube. The hardest task builders face at this stage is believing how much small changes in the burner will effect the flame at this point. Hang in there just a little longer. You're almost there.

[u_p_country]

Another Franken Burner That is a great explanation of a burner flame!  Being a visual learner, your illustration makes perfect sense. I think the pictures are pretty close to what is visible to my eyes though some more run time will tell.  If it's running "rich", moving the accelerator forward, toward the flame, should help to "lean" it out, yes?  Am I understanding the theory correctly?

Mikey 98118 You caught me!  I was so excited to fire it up that I didn't finish all the details that needed doing.  Patience is not one of my strong points.  I have several of the .025" MIG tips and will give one a try.  My understanding of the MIG tip sizing is still a little fuzzy, going down in size helps the burner by accelerating the gas flow?

After reading the last 60 pages of this thread over the course of a couple weeks, you have convinced me that small tuning adjustments, one at a time will yield big results.  While on the subject of tuning, I haven't read, or maybe I have missed a list of the things that can be tuned on a burner and what their impacts are.  Of course they are all tied together and one change will affect the others, but my mind craves a checklist.  Flame nozzle overhang, MIG tip size, MIG tip location (forward or backward), choke position (if present).  Am I missing anything?

Thank you for the encouragement!  Looking forward to some more shop time.

[Mikey98118]

1 hour ago, u_p_country said:

If it's running "rich", moving the accelerator forward, toward the flame, should help to "lean" it out, yes?

There is a sweet spot somewhere between 1/4" and 3/8" between the MIG tips end and the forward end of the air openings; that spot will give the best flame results you can get out of that particular variable. Tuning one of these burners involves a number of variables, each of which can only provide a limited amount of help.

[u_p_country]

Well after switching to a .025 MIG tip the mikey burner runs so much better. It can produce a nice flame that matches up nicely with the earlier "ideal" flame pictures.  Sorry no pics, my phone's camera is distorting the colors too much to be useful. I'll have to try my old digital camera. Now I'm having trouble getting the choke open all the way without blowing the flame of the nozzle. Seems like that means I'm getting closer but I might be all wet there. I was running at 8 psi.

Just for kicks I mounted it in the forge and voila! Full range of opening on the choke and nice flame all the way through the range of pressures all the way up to 40 psi! So I'm stumped for now.

My next step is to clean up the air openings and fine tune the fit and finish of the burner as Mike suggested. That will keep me busy in my odd spare moments this week.

Thanks again all for your help. Gosh this is fun!

 

[Another FrankenBurner]

Congrats u_p_country.  It's a great thing when the burner works after all that work.  

In order to get decent pictures, I have to be in a medium-low light, focus directly on the flame and sometimes lower the exposure on my camera.  

Speaking of pictures, here you go Mikey.  These are a 1.5 inch stainless nozzle on one of my 1/2 mix tube burners.  Sorry about the background clutter.

This picture shows the true nozzle temperature/color on the outside:

Here is the same flame with the camera exposure lowered to see the flame:

I am now using refractory nozzles only.

 

[Mikey98118]

On 3/23/2019 at 9:27 PM, u_p_country said:

going down in size helps the burner by accelerating the gas flow

It allows you to accelerate gas flow, thus tending to create a leaner gas to air mixture. It is not a very satisfying bit of data for beginners, but everything about burners, and the equipment they inhabit always boils down to balancing various factors against each other.

Thanks for the flame and nozzle photos, Frankenburner. I think they will be a revelation to a lot of people; they sure were for me

[u_p_country]

Thanks for the ideas about camera, I didn't think about decreasing the exposure, I'll try that next time i'm out in the shop.

 

[Mikey98118]

These last two photos show flames I can't very well interpret; they are beyond my expertise. But the incandescence on their flame retention nozzles aren't. They are both showing heat levels Mikey burners can only attain with propylene fuel--not on propane, like he is using. To learn more about these burners, which are the future, look in on the 3D printers thread.

[Frosty]

I'd like a shot from a little farther away and with a more uniform background. They look really good so littler things are having greater effect evaluating them. 

Looking really good from here.

Frosty The Lucky.

[Mikey98118]

Other indications are strong too. 1/2" burners supporting 1-1/2" diameter flame retention nozzles with full sized flames !?!

[Another FrankenBurner]

I will work on better pictures.  I like evaluations and any extra information.  

[Mikey98118]

On 3/23/2019 at 9:27 PM, u_p_country said:

  Of course they are all tied together and one change will affect the others, but my mind craves a checklist.  Flame nozzle overhang, MIG tip size, MIG tip location (forward or backward), choke position (if present).  Am I missing anything?

Part centering is the only thing you missed. You can have the gas tube dead center and axially parallel, and still have a MIG tip that is bent out of alignment; most of them are only soft copper, and can come bent right out of the package. Even more common, but lest serious is a flame retention nozzle that is positioned out of axial alignment.

Why no list is a good question. The answer is that we deal with loads of different burner designs here; mine is actually the least common that comes up for questioning. All of us can see some burner problems at a glance; other problems can be obscure. Most people are feeling pretty vexed by the time they get to tuning the burner, and we have to sort out the facts while dealing with pretty raw feelings. It can be hard for people to maintain an even keel when we inform them that their view about what the flame out of their own burner is doing happens to b totally different then what we are seeing.

[u_p_country]

Mike, I have been working on getting things centered in my burners so I'm surprised I forgot that one.  You and others do a great job of walking that middle road of teaching the ins and outs while encouraging us newbies to keep going.  Thanks!

[u_p_country]

Just a quick update on my 3/4" mikey burner.  Before work I spent a few minutes in the shop and came up with this flame.

This is a 0.25 MIG tip at 8 psi. I forgot to measure nozzle overhang but the gas tube is about 5/16" back from the front end air openings.  Choke is 3/4 open. Any further and the flame turns purple and wants to blow off the end.

[Mikey98118]

Congratulations; you're there

You will be very happy with that flame in your forge.

[u_p_country]

Excellent!  That's what I was hoping to hear, but didn't want to jump the gun.  It was a little daunting posting my pics up for review, but The help has been so tremendous, It was worth a little trepidation.  Thanks again to all for your help!  I'll post pictures over in Forges 101 of my forge up and running when I get a final coating on the wool.

[Mikey98118]

Great! After all; it's all about the forge. Burners are just one part of that equipment

[u_p_country]

Mike,

I noticed that the burner Corey/soopafeen has been posting about has a much different construction method for the end cap and gas tube holder.  He also mentioned, I think in his first post IIRC, that you had given him some direction about building it this way. Could you give some more insight into this?  Or maybe Corey/Soopafeen can jump in and give some insight, or more photos?  Maybe you already did and I missed it.  Now that I have one burner going to my satisfaction, I have to build another!

[Mikey98118]

It's pretty simple. This is an interactive forum; not a how-to book. So, there is a lot more leeway for people to do things as they prefer, while consulting, to keep them "out of the ditch." If people read up on burner principles, where is no reason not to work with the materials they have on hand. Cory has proven that he knows enough to give good advice, so why not, if he's willing.

[Soopafeen]

Hey U_P_Country,

Mike has been more than helpful on my adventure, I just want to start off by saying he is the MVP here to be pointing us all in the right direction here on IForgeIron so we can all have a great experience hammering.

The new Mikey Burner design utilities a brass plug pressed into the end of the mixing tube for example my stainless 3/4" burner actually has a nominal I.D of 0.884" so by employing a slightly oversized Brass round bar at 0.937" and taking off enough material that it wants to mate with the end of the mixing tube and applying enough pressure that the mixing tube blooms out a little bit the brass round creates a air tight plug almost like it's been welded together, the brass bar is soft enough to work with so for what ever you are unhappy with the fitment you can easily take off material as needed.

My burner started with 1-1/2" of brass round length and due to having already made my 3" gas accelerator (wish I had bought one at 3.5" instead) I had to take off about 1/4" to get a proper adjustment for my jet and the alignment has been spot on, I would say you could probably get away with 1" of length which is still massive surface area to hold your accelerator parallel to the mixing tube.

Picture #1: Complete burner parts.

Picture #2: Burner accelerator port.

Picture #3: From inside the mixing tube.

Hope that answers your question.

Also Mikey recommends using gasket or thread sealer on gas plumbing for a proper air seal and I have to agree with it's results.

Thanks, Corey

[Mikey98118]

The middle photo shows me a much thicker tube wall than I had thought; it will need beveling

Or maybe not; the flame is already very hot.