Burners 101

[Mikey98118]

Two different conversations here. In the first place, there isn't a single burner in my book that doesn't have way more area than  40% larger than the burner's internal cross section; they were figured out to be generously larger than that minimum, and then were lengthened to provide other benefits when engaging the sliding choke. Perhaps I should have stated that the total width of the openings would not change. Sating that the total area would not change is also correct, but possibly confusing for you?

[bluesman7]

On 5/6/2016 at 10:02 PM, Mikey98118 said:

 

 You only need about 40% more surface area from all those air intakes put together than what is found in the cross section of the burner tube's pipe, so they never needed that mess of gopher holes to begin with; there is a lot more to say on even just this subject, but first lets see if we can even get through with the "knockdown drag out" over these statements. Let the feathers fly. 

 

Thanks Mike,

. I went looking for it last night  and found the post that lead me to this conclusion. It's in the very first post of the thread. I will be making the slots bigger that this, but part of why I'm trying this is to see how much shorter I can make the back end of the burner. Also I got the idea from other parts of this thread that having a higher sideways velocity at the intake promoted more swerl in the burner tube to help mixing. As I said in my first post I already have a burner that is working fine for me. This burner is more to satisfy curiosity, and get my choke on the back side of the burner where it belongs. If it works better, that's icing on the cake.

[bluesman7]

I ended up with three 3/8" x 1.375" milled slots with the business ends squared. A total of 1.5 sq. in. or 250% of the 3/4 pipe area. I have not put the choke on yet but a quick test using my hand as a choke showed that this was enough porting, I would not go with much less though. I passed my copy of "Gas Burners for Forges etc." on to a friend a couple of years ago and do not remember how close this is to the designs in the book.

[Mikey98118]

It sounds to me as if you are doing fine. Flame photos are always a help, though

[Mikey98118]

14 hours ago, bluesman7 said:

Also I got the idea from other parts of this thread that having a higher sideways velocity at the intake promoted more swerl in the burner tube to help mixing.

Yes, that is true. On the other hand, reducing the width of these openings helps smooth out the flame; as so often the case, it is a question of balance. You can make these burners do a whole lot more than just burn hot. It is possible to sculpt the flame as you please, by continuing on along the road you're on.

You mentioned wanting to shorten the burners, If you insert internal fines at the front end of the mixing tube, the flame of a burner with more swirl can be smoothed down that way too, allowing the mixing tube length to be shortened. I don't bother with such tricks, as people already think my burners are too complicated. But, if you want to improve them, there is still plenty of room left to do so.

That should have read "fins"; not "fines."

[bluesman7]

6 hours ago, Mikey98118 said:

It sounds to me as if you are doing fine. Flame photos are always a help, though

I'll try to get some pictures up next week. Life is interfering with finishing the choke and nozzle even though there is so little to do.

[Mikey98118]

There is a way to get enough time; its called retirement. My advice is to put it off as long as you can.

[Mikey98118]

May we have page 26 please?

[Mikey98118]

Making Oz burners

Both designs are linear burners, with concentric  reducer fittings, and that is where all common ground with an Oz and a Riel burner ends. In the first place Oz burners use a larger reducer. Try for 3:1 ratio for the inside dimensions; if you can't get close (within a 1/4") to them, go with a larger Ratio--not smaller. Most guys aren't willing to  grind away the internal thread, and turn that whole area into an inside bevel, but if you do, the additional work will produce additional benefits. Its handy that the saddle can be removed, and the bevel ground later on.

The gas pipe is one-half of a 6" long schedule #80 1/8" pipe nipple (McMaster Carr online catalog), so it's wall is thick enough to tap 1/4-27 or 1/4-28 machine screw thread inside the cut end, for a Tweco style MIG contact tip; this now becomes the burner's inline gas tube, with an inline gas jet, which is the only way to make a powerful homemade burner. The other end, which still has a 1/8" tapered pipe thread, ends up connecting to the fuel gas source.

Note: This design needs no drill press. A 3/8" hand drill is fine; or a 1/4"drill, with a step bit will work.

1/8" IPS (Iron Pipe Straight) thread (AKA lamp thread), dies for which can be had from eBay and other online sources, are then run as far down the outside of the gas pipe, from the cut end containing the MIG tip, as you need.

A flat bar (width determined by size of reducer fitting, but make it wider than you think it needs), is bent into a "U" shaped bracket, which I call a saddle for reasons that will become clear; it should fit over the large opening of the reducer, without slop. Drill two small holes for machine screws, in each open end of the flat bar, and one hole in the center of this saddle; thread the center hole with a 1/8" IPS tap, and assemble the MIG tip, gas tube and saddle ("U" bracket), with its open ends facing the MIG tip.

Place the gas assembly, saddle down, on on the reducer, and screw the gas tube into the reducer until its end is protruding out of fitting's  small hole. Choose whatever method you like to make a centering spacer, wood, tape, or drill a plug fitting; it really doesn't matter. What you now have is all the parts that need to line up, perfectly in line for drilling the four small screw holes; with any care used at all, this is now a slam dunk.

Nine diameter rule of thumb applies to this burner series. Yes, these burners have a fast enough mixture flow to support stepped flame nozzles. Gas orifice sizes are the same ones I always use.

Because the gas tube has outside threading, you can also cut out aluminum plate with a hole saw, to make a choke, and thread it, to screw back and forth on the gas tube.

If your gas tube ends up with a loose fit in the saddle buy a lamp nut in the lamp area of you hardware store, to act as a locking nut.

So, why bother building this burner?

(1) There is no easier burner to construct, with dead center aiming.

(2) It is a powerful, and trouble free design.

(3) Its choke can be exactly positioned, or closed tight against chimney effects, with a flick of the finger.

(4) I think, that the burner's extra wide saddle forces incoming air to begin swirling sooner than would otherwise happen in the reducer fitting; I base this personal belief on observations of several burner designs, which run hotter than I can otherwise account for.

Why call them Oz burners? Linear style homemade gas burners seem to have first appeared in Australia, before we Yanks copied them, And it was while looking at an Aussie interpretation of an English burner that the idea of a simple bent saddle to hold the parts together came to me. So, since they have had so much influence on our gas burners, its time they cot a little credit.

Plus, ticked off would-be makers can have fun calling them Odd burners, while banging them on a handy hard surface; its only fair

[Mikey98118]

Chapter 2 is meant to be a resource, where the reader can go to get back up information before deciding what fittings or hose to use, or why the burners are built the way they are; not something to be waded through with dogged determination

There are people selling good burners:

Chile Forge builds Mikey burners, but only in one size.

Hybrid Burners.com sells very good burners in a variety of sizes.

Larry Zoeller Forge sells his "Z" burners, and also kits for them; they have a good reputation.

There are probably others, but I don't know who they are. I do know there are lots of people seller bad burners out there.

12 hours ago, Scrambler82 said:

Also, Mikey you were saying in a message that some of the designs in your book are older, but they appear to be far ahead of what is being sold in some of the Commercial Forges.

Yes, that is sadly true. All of the well known commercial forge brands refuse to update their technology; it's enough to make a guy think they're just in it for the money...the only one of them with high customer satisfaction is Diamondback. I figure the others are trusting in the general ignorance of their customer base to get by. With companies like Chili Forge coming on line, I think their number well be up pretty soon.

[Mikey98118]

What is a 1/8” IP thread? 1/8” IP or IPS (iron pipe, or iron pipe standard) thread dies and taps are used to make lamp rod thread (1/8-27) on the outside of 1/8” pipe (designated size; actual outside diameter of 1/8” pipe is .405”). This is parallel thread, and is not to be confused with the tapered 1/8” NPT (national pipe thread). Tapered thread is used on the ends of pipe nipples to mount your gas tight fitting or needle valve to. Be sure to use an "S" letter drill bit; not an "R" bit, which is recommended for tapered pipe thread; not for parallel lamp thread.

[Mikey98118]

What constitute "easy to build" is different on miniature burners.

the primary concern in larger burners is developing a really hot flame; tuning is a minor detail.The major problem with building a 3/8" or smaller burner, is that, starting at 1/2" sizes and increasingly as the sizes reduce, burners become touchier about construction details and tuning--every burner design does--while greater flame heat is almost a given. In miniature burners, an easy to construct design must include a large choice of key parts to choose from, and the maximum possible parts do be tuned. A tube burner gives the maximum amount of parts control, but It is not an easy design to construct.

But wait; tuning is a pain in the six, so why would we want to complicate it further? Because not being able to fine tune a miniature burner, often means it won't run at all. After all the trouble put into its construction, a pain in the six beats out a totally busted six, every time!

Linear burners are the easiest design for building in miniature sizes, because what is added to the mixing tube or pipe is only a reducer fitting, which probably has the largest amount of part choices of any pipe fitting; it is also the easiest fitting to make changes in by grinding. Linear is the smoothest burning turbulent burner design in the first place, and can now be made with all the controls of a tube burner. Choke control is usually absent, or at best crude on old linear burners. The ability to move the gas jet's distance to the mixing tube orifice has been absent in the past. A gas tube that is threaded into a saddle mounted on the reducer, allows both improvements, and with very fine tuning of them. A drilled saddle on a reducer fitting can be mounted so that the gas tube and jet, are easily positioned axially true at the same time.

[iamjoe]

Folks,  

I hope I'm posting this in the right place. 

I've built a new burner tonight and could use some of the knowledge from you gents. 

I'm using 1/2" burner tube 6". A pipe cross for the air intake and to secure the jet tube. I have a .035 welding tip for the orifice. I can adjust the jet tube in and out and for center. I've moved it all over and this is the best flame I can get. I have a 0-40 psi regulator, no gauge but this is two full turns on the regulator. If that helps.

20170622_203850.mp4

[Buzzkill]

joe, there are at least 3 things about your burner which are at odds with my understanding of the burner type and size you are kind of trying to build. 

A general rule of thumb for this type of burner is that the length of the tube is 8 to 9 times the diameter, so you're about 1.5 inches longer than the optimal length. 

Next, you are using a cross with the same size openings all the way around.  For a Frosty T burner you'd use a reducing T with 3/4 inch openings for the air and the 1/2 drop for the burner tube.  This may not seem  like a big deal to you, but the components were chosen to match air intake with fuel within normal operating parameters.  Your setup may not allow enough air to be pulled in with the fuel stream. 

Finally, the .035 mig tip is far too big (percentage wise) for a 1/2 inch diameter burner.  The closest match in mig tips is .023. 

So, if you add all that up you have more fuel than you should have going in, not enough air drawn in with the fuel, and a tube whose length is past the optimal point for mixing vs. friction.  Since your burner has some rather fundamental flaws it's not surprising that you are unable to tune it well.

[iamjoe]

Buzzkill, 

Thanks for the feedback. I was thinking it was running rich. Will definitely change the tip and go from there.

[Mikey98118]

"T" burners are Frosty's design, and lots of people are building them, including the smaller sizes. So I will lay back and let Frosty and the gang comment on how to reconfigure and adjust this very worthwhile burner style. I have been waiting to see some lively discussions on where to find parts for smaller "T" burners, and possible trade-offs to build 1/2" and 3/8" burner sizes, on this thread. And don't forget that "T" burners have there own thread, if you can't find what you need here. Still, design issues go right to the heart of what this thread is for.

[VainEnd84]

I tried using a 1/2" pipe cross to build a "T" burner and found that it could not be tuned properly, you simply can't get enough air, I suspect if you machined out the inlets so their internal diameter is the same as a 3/4" pipe T that that would solve the issue but that requires access to a lathe. I also tried using a 3/4" pipe cross and a reducing bushing so I could go from 3/4" to 1/2" but it creates a great deal of turbulence and an unstable flame. I suspect if you could get a properly machined reducer with a smooth taper this issue would be solved but that would require some very good machining. If there were reducing pipe crosses on the market that too would solve the issue but I have not been able to find any anywhere. I contacted a machining shop near me who could manufacture the part but the cost was about $300 and for that I would rather just buy an already machined and finished burner.

[Mikey98118]

It isn't surprising that no matter how much we know, there is always more to learn. What is surprising is that becoming expert at something can become a trap. Add a dollop of willfulness about what we "know", and the trap springs shut! What is known about burners should be held in an open palm, for all to see, and think about. I learn other people's truths here; they allow me to progress in directions I would never explore alone.

[Mikey98118]

1 hour ago, Scrambler82 said:

unless you really want to build your own you can buy a Mikey Burner for $200 + shipping, x2 for me, why build it ?

Unfortunately, the only source of Mikey burners is Chile Forge; they started with the 1" burner size to run their oval forges, and did originally intended to build other burner sizes too. But I think they got sidetracked by forge sales, and never did get around to building the other burners. This particular burner series is much better suited to mass production than to single builds, since the air openings can be cut and beveled by high pressure water jet.

After the book came out, prices on rotary tools and their accessories plummeted, making them the obvious choice for individuals to cut out air openings and do the beveling with, but since that fact isn't in the original text, it tends to get lost in the shuffle, making the burner much harder to construct. Also I haven't used pipe fittings to construct these burners in years. Tubing is harder to obtain at the beginning of burner construction, but ends up needing far less work overall. For instance, seven set screws for the flame nozzle changes to a single screw, when using tube. The art students I wrote the book for, can now choose between several easier to build burners that were not available them. Everything changes over time.

[ppancho]

Hello

First: Mikey thanks for your book and this thread. Please continue this is a great learning.

Second: (with ignorance of English and ambiguity of translation Google translates me to the question)

The width of all air holes is as many as the diameter of the burner tube?

Thanks

I know it was written here, but the ignorant of English forces me to ask.

[bluesman7]

On 6/17/2017 at 1:58 PM, bluesman7 said:

I ended up with three 3/8" x 1.375" milled slots with the business ends squared. A total of 1.5 sq. in. or 250% of the 3/4 pipe area. I have not put the choke on yet but a quick test using my hand as a choke showed that this was enough porting, I would not go with much less though. I passed my copy of "Gas Burners for Forges etc." on to a friend a couple of years ago and do not remember how close this is to the designs in the book.

Hi ppancho,

Not to answer for Mike, and I will be very interested in what he adds to this. I had luck with the slots as described above. Flame pictures coming soon.

[bluesman7]

Some flame pictures.

[Mikey98118]

Hey, blues:

First, that is a strong flame; not a weak one. Many guys would use such a flame in a forge, and never look back, but it needs work. Go back three or four pages and you will find a similar flame, that just needed a little adjustment in the burner to run properly. I would begin by reversing the direction that the choke opens from. It needs to open up from the rear of the burner.

11 hours ago, ppancho said:

Second: (with ignorance of English and ambiguity of translation Google translates me to the question)

The width of all air holes is as many as the diameter of the burner tube?

Having English as a second language isn't that much of a handicap. The biggest hurdle in dealing with metal work is understanding the technical terms; that places you in the middle of the class curve, along with most Americans today, because they are not taught anything about those terms unless they grow up in a trade. You at least are not surprised or dismayed by your language difficulties. Most of my fellows are surprised, and quite frustrated with theirs. I don't mean having to deal with concepts like square of the distance, or terms like perpendicular, but obvious things like I.D. (inside diameter), or the names of different types of thread. Things that many guys assume are beneath them. But anyone who takes that tack will run aground when trying to deal with sales clerks at a welding supply, or hardware store.

The sum of the area of all three air openings was what the quote was about. Now please do me a favor and forget all about that figure; it is misleading, because it is beside the point. If you follow my directions on ANY of my burner designs, you will far exceed the figure in question. I brought it up a long time ago, with the intention of laying it to rest, as a consideration. What is happening now is just the opposite of what I intended!!!

Both the width and length of air openings on a Mikey burner are figured to get the best possible flame characteristics from a given burner size; that goes far beyond a minimum area in the air openings; it's all about fast flow and sufficient swirl of incoming air. So, here is Mikey's rule of thumb for burner design: Forget minimums; go for maximums. Its a lot easier to rein in a wild running burner, then to perk up a weak one.

 

[bluesman7]

3 hours ago, Mikey98118 said:

Hey, blues: I would begin by reversing the direction that the choke opens from. It needs to open up from the rear of the burner.

 

Ha!  That is what I thought I had cleared up in these two previous posts.

On 6/16/2017 at 1:48 PM, bluesman7 said:

 Also on my first burner I have the choke sliding in from the burner side. I've seen the chokes either way, but I want to experiment with the choke sliding in from the gas supply side. Have you noticed differences either way.

 My thoughts were that since the burner is tuned by the mig tip to mixing tube distance, sliding the choke the way I did keeps that relationship constant. Sliding it the other way effectively buries the mig tip into the tube as the choke is engaged.  

On 6/16/2017 at 2:45 PM, Mikey98118 said:

 

The choke is supposed to slide forward from the rear of the burner, to give a smooth increse in air flow.

I misunderstood your answer. My first burner works the way that you're suggesting and I've always thought it was wrong.

 Oh well, that will be a very easy fix. I can do that tonight. Thanks for your input.

[Mikey98118]

Your problem may turn out to be something else, but until your choke allows air flow to become predictable, we cannot get to any other cause.