Burners 101

[Frosty]

Just going by the volume it'd be in the curve for a single well tuned 3/4" burner but it's long and narrow so a single burner will mean ann uneven temperature. 

The burner to furnace volume ratio seems to be holding pretty true with the NARB. (I gotta change the name of that, they can be virtually any shape so "ribbon" isn't really very accurate)

In your application it should make even heat in a long narrow chamber like you propose. The original two NARBs are 6" long and the flame lengths are pretty even over the whole length with the center ones slightly longer, less than 1/4 difference center to ends. If a person wanted to make one longer it MIGHT need a diffuser to even the fuel air pressure in the plenum but I haven't messed with longer.

Frosty The Lucky.

[Mikey98118]

Making miniature gas jets from capillary tube & MIG contact tips, etc.

For building a gas jet from fine tubing (capillary or hypodermic) and a MIG contact tip, I recommend using a Tweco, Miller, Lincoln, or Radnor 1-1/2” long tip (excluding their threaded portion, which is 1/4-27). If you can get a tapered tip, that’s good; otherwise you will have to spin it in a drill under a file, to taper it yourself.
Just because there is a welding supply store in your town doesn’t mean that they will have the MIG tips you need in stock, or that they will bother to sell you one or two of them, even if they do. Your sale is hardly worth their paperwork. You can buy MIG tips on line as few as five or ten at a time for less money than they will cost at your local welding supply store, and chances are that the shipping charge won’t amount to more than the gas and time you may waste receiving a rotten experience, while trying to buy them locally: Radnor and Tweco Model 14T-052 MIG contact tips are available from amazon.com, or eBay.

Stainless steel heavy wall capillary tubes are found in outside diameters of about 1/16”; that can vary from .060” to .065” diameters depending on the manufacturer, and MIG contact tips can vary by up to .003” in the diameters of their orifices; so, you may end up with an interference fit that requires little effort to mount Or you may need to swage the MIG tip down around the capillary tube, silver braze the tube into the MIG tip, or you could even need to drill the MIG tip hole a little larger.  Because stainless steel capillary tube comes in vary limited inside diameters, and you may elect to employ EDM tube.

Miniature burners (3/8” size and smaller) bring up for the first time, an instance where friction of the moving gas molecules down these tiny orifices become a major design factor. In larger burners the smaller the gas orifice diameter the hotter a given size of burner tends to burn, in even the longest available MIG contact tip. Now, do to friction we find a 1/2” long capillary tube (within such a tip) if .020” inside diameter will make a hotter output flame than 1/2” long tube with this diameter. It becomes necessary to adjust the capillary tube’s length, to overcome the lack of orifice choice sizes. In the case of a 3/8” size burner, you can only choose heavy wall stainless steel capillary tubes with .020” orifice diameters, and then cut and sand it down to a finish length in the MIG tip of .406” (13/32”) long, to gain the best result from this part.

Torch tip cleaners are made from a harder stainless steel alloy than capillary tube, but it isn’t so much harder that they can be successfully used to bore orifice sizes larger, but they are perfect for using them to get rid of internal burrs, so that the holes where the fuel gas inters and exits the tube can be made round; use a magnifying glass to assure this result.

    Heavy wall brass or even copper capillary tubing, normally employed as electronic discharge machining (EDM) tubes, can also be used as gas jets. Even thin wall stainless steel hypodermic tubing can be used, so long as both its inside and outside diameters are listed; it is available as dispenser needles, and as 3’ to 5’ lengths. MIG contact tips come in limited orifice diameters, as do capillary, hypodermic, and EDM tubing. You must begin your search for a convenient tube with the desired orifice size (inside diameter). Next, you try to find a MIG tip with as close a match to its outside diameter as you can. Saturn Industries, Inc. has been a practical source of such tube in the past.    

    If the tip’s diameter is within .005” oversize to the tube, it is easily swaged down to trap heavy wall tube in it; with a tapered MIG tip, you may be able to create an interference fit by squeezing plyers around the thin section of copper. With a plain (not tapered) MIG tip even thin wall tubing can be swaged into the MIG tip, but you have to drill a 1/4” diameter hole in a short piece of 1/2” x 1” mild steel bar. Begin by scribing a line on the 1” face of the bar, somewhere near its center, using a combination square. Then scribe a second line from it, over the 1/2” face. Use the square to find the center of the line on the 1/2” face, scribe a cross mark, and center punch it; drill a 1/4” hole completely through the bar. Use a thin cutoff disc to cut completely through the bar at the first line, and then clean off all burrs.

    Slide the desired length of capillary tube into the MIG tip, and place it within your new swaging die; Tap its top with a hammer. Cut off the excess tube to within a 1/16” beyond the die, and hand sand it back even with the MIG tip’s face. Then clean out any internal burrs, with torch tip cleaners.

If the MIG tip’s orifice is only a little too small for the capillary tube, You can use torch tip cleaners to enlarge it a few thousandths of an inch. You will find one round file in the set to be     small enough to push back and forth within the MIG tip, while turning the tip slowly. Every few moments, you need to check the enlarging hole against the capillary tube, as it gradually increases.

    Wire gauge drill bits can be hand spun in a pin vice to enlarge holes in MIG tips to within a couple of thousandths of an inch of your capillary tube; keeping the hand filing (with torch tip cleaners) from becoming tedious. Only increase the size of thousandths of an inch at a time, when drilling in copper. Don’t depend on your eyes for guidance. Pay close attention to the amount of tension felt in your fingers. Start drilling by barely touching the bottom of the tip’s hole. Stop frequently to clean burrs out of the drill bit, and blow them out of the MIG tip, from the hole’s other end. When you feel a sudden increase in tension on the bit, reverse its direction until the hidden inner burr in the hole is knocked loose, before continuing to drill.

    You must drill as deep as you can into the tip, starting from the threaded end. By the time you must switch ends to complete the hole you should have learned how to drill well enough to mate up both ends. Because you don’t have a miniature drill press and drill vise ($$$), your hole is going to end up oversize at bother ends, which will both taper down smaller as the hole gets deeper. You may be able to push up to a 1-1/2” long length of hypodermic or capillary tube into it with just enough interference to trap it in place with the help of a few light taps. Or, you may have to finish up the hole with some help from torch tip cleaner files.     

    It is important for the outside of MIG contact tips in most burner sizes to be tapered for proper flow of the air, as it passes by the gas jet on its way from air intakes into the mixing tube, or into the mixing area in tube burners. How important? How small is you burner? The smaller the burner the more important it becomes.

    MIG contact tips come in several orifice sizes, as do hypodermic needles. Just as heavy wall capillary tube can be made to serve as proper gas jets in small burners by varying short lengths to match output velocities of different gas orifice diameters to different mixing tube diameters, so can capillary and hypodermic tube serve the same purpose by varying longer lengths of larger diameters to overcome tolerance changes in those orifices. Also, the longer lengths can be more easily interference-fit in place or bent in a bow to keep them in place, without need for silver brazing. Lengths and diameters will remain a matter of trial an error, because of tolerances; plus or minus .001" of an inch is a lot of difference when the orifice is .023" or less.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      

    Remember, the mounted capillary tube must be closely inspected under a lighted magnifying glass to make sure all burrs are completely eliminated from the tube’s orifice; it needs to be completely round; not jagged; otherwise the gas stream won’t be smooth

Tapered watchmakers reamers are called pivot broaches; they are another tool for enlarging deep micro holes in copper, and brass; tapered micro reamers

Note: Diamond reamer sets are meant for working on glass beads, and are too crude for reaming drilled gas jets a few thousandths larger. What they are good for is shaping long tapers into MIG tips and capillary tubes behind such holes, to increase gas flow into them. They are a low cost handy tool to keep around for deburring small holes, and working in inside corners, etc.

Pivot cutting broaches allow faster hole enlargement then drill bits, and also serve to bridge any gap in bit sizes and needed orifice diameters These broaches are very small, and fragile; they must be mounted in pin vises, just the same as tiny wire gauge drill bits are, and handled with the same kind of delicacy, with the same motions, lest you bend the broach, or snap one off in the hole. Although handling these tiny broaches takes care, they don’t require much work, or time to do the job. You will probably want a lighted magnifying glass and a pair of tweezers, to pick out the right broach from a set of them, for mounting in the pin vise.

    The new orifice will not be parallel, but will end up slightly tapered; probably by less than one thousandths of an inch all around the periphery of the capillary tube. If, you are committed to silver brazing a capillary tube in place, continue reaming, until it will slide into the tip to its desired length; its end will stop against the wall of the tapered MIG tip’s orifice; helping to stop the filler alloy from plugging up the capillary tube.

    If you would rather avoid silver brazing, cut the capillary tube 3/16” over of the desired length. Place the tube in the MIG tip, and screw the tip into place in base of the burner (or within a threaded hole in a block of steel; whatever). Tap the whole assembly against a metal surface, or tap a hammer against the excess tube, until it comes within 1/8” of the MIG tip’s front face (tap it—don’t slam the hammer). Use a circular motion on very fine sandpaper (at least #400 grit; finer is better) to reduce it down even with the tip’s face; use the torch tip cleaners to remove the tube’s internal burr.

 

Rotary tool and micro drill

Electric rotary tools are the answer to overpowered electric die grinders, which are a grim necessity to unlucky professionals, and should be avoided like a potential trip to the emergency ward, by novices. This leaves electric rotary hand tools as the frequently under powered and overpriced alternative. There is a type of micro drill that trades lower RPM for higher torque; this tool is just right for power grinding and sanding on small parts; it can be slid along inside a split pipe, taking the place of a drill press for making acurate micro holes in burner jets. The tool’s low price seems almost to good to be true; it isn’t though;  I bought one last week; its body is a 1.585” diameter aluminum cylinder, that is 3-3/4” long; its speed is 20,000 RPM; the highest recommended speed for a 1-1/2” cut off disk, and still about right for most micro drill bits. Its price is $27; cheap for two essential tools in one

   Silver brazing capillary tubes

Most air/propane torches have gas jets that can be removed, drilled, and silver brazed, in order to mount a capillary tube in place directly within it. While this involves hot work, it is also more tolerant about drill alignment in small burners, as the capillary tube can be easily bent after the jet is replaced in the goose neck, if your hole wasn’t drilled quite parallel to the part’s axis.

    Most old gas jets contain a spongy looking section, which is meant to act as a fuel filter; unfortunately they just end up doing a fine job as a clog maker. Drill completely through the sponge; it has no value. Following this method enables you to re-task nearly any air/propane torch.

    While there are a variety of sources for capillary tube, the easiest way to find any particular orifice size you need, still remains blunt end dispenser needles; all of which are stainless steel. Most easily available heavy wall capillary tube, or thin wall hypodermic tube, is also stainless steel; Stainless requires the use of brazing alloys that contain 50% or higher silver content (the higher the better it wets part surfaces), and flux that is rated for use with stainless steel; most of these are black flux. I recommend Harris white flux for use on stainless thin wall tubing, rather than black flux, which is likely to be too aggressive for thin wall tubing.

    Just before brazing, use fine grit sandpaper to break up surface oxide, and to scratch up the tube’s smooth surface, wherever you want the silver braze alloy to adhere. Equally as important is to keep the flux well away from areas you don’t want the filler alloy to overrun, like the end of the capillary tube.

Handy Flux Type B-1 for brazing stainless steel, nickel, tungsten, and super alloy; effective from 1100 to 1700 °F (593°–927°C)

  Rio Grande 65% silver content brazing alloy #3101100, which is excellent and inexpensive; it is especially recommended for small pieces, such as stainless needles and capillary tube It is best to  add flux to a length of tube, and push it into the MIG tip, leaving excess tubing protruding from its end; then cut, sand, and deburr the tube to fit, after brazing.

Note: the higher silver content (50 % or more), which helps joining alloys to wet stainless steel, nickel, and tungsten, also does a superior job of wetting copper and brass.

Brass or copper EDM tubing can also be used to provide the right size gas orifices, by combining them with MIG contact tip holders of other sizes. Various diameters of Drawn brass and copper tubing are available through Saturn Industries

Heavy wall nickel and stainless steel capillary tubing can be hard to find in desired orifice sizes, but are still available from Small Parts, which is now owned by

If you have the choice, I recommend heavy wall capillary tube (AKA gauge tubes) over thin wall hypodermic tube, if you can find them in the orifice diameters desired (as they are far less inclined to be partially dissolved by flux, should you be a little slow in your braze work). Different companies have various orifice sizes available; one of them well stock tube in .020” inside diameter, and another will stock .023” instead

Various heavy wall stainless steel capillary tubes are also available from

1/16” O.D. in various inside diameters are available from Sigma Aldrich

1/16” (.0625”) O.D. in various inside diameters are available from Lab Express

[Mikey98118]

My favorite way to make a gas jet for a  3/8" gas burner, with a high speed flame, is to insert a 1/64" O.D. by .020" I.D., by 9/16" long stainless steel heavy wall capillary tube in a 14T (for tapered) Tweeco MIG, and to sand the end back somewhere between 1/64" and 1/32" shprter, during final tuning, to dial in its performance.

It has turned out that the turn- down range of 3/8" Mikey burners are long and smooth; therefore a 1/4" burner is kind of gilding the Lilly.

[Mikey98118]

Linear versus jet ejector mini burners

 

Jet ejector burners tend to burn hotter than linear burners. Linear burners tend to run smoother than jet ejectors. The smaller the burner the harder it is to build and tune perfectly. The building aspect has to do with the differences between available parts sizes and optimal parts sizes; they grow as the burner shrinks. The increased difficulty in tuning seams to be an aspect of whatever makes smaller burners tend to be hotter burning. I admit not knowing the why of this, but it is easily observed.

The conclusion, for now, seems to be that 1/4" and smaller jet ejector burners are simply more trouble than they are worth; this idea is bolstered by the emergence of saddles as a method for mounting gas assemblies on linear burners; thus, opening up many new choices of practical air entrance devices.

[Square Nail]

On 5/20/2017 at 3:43 AM, Mikey98118 said:

 

Mikey and Frosty, at the risk of getting flogged for bringing up this situation again, I am lost as to what to do with my Frosty 3/4 T burner. According to Frosty his burner can be tuned in the forge. Which when I first fired my forge the burners looked pretty good or so I think! But after the forge was lined and fired I get extreme dragon breath and cannot see much blue below the opening in the kastolite.  I have adjusted the flares down to 1 1/4" over the end of the burner tube , but don't want to adjust the mig tip yet. Because of not wanting to change a bunch at once. With my limited knowledge I think it is way lean because of the lack of blue flame and the large amount of white and orange flame. I have a picture that I will post as soon as I can get it off my phone. Do I need to start from square one outside the forge or is there something I'm missing! Thanks for your help!

[Mikey98118]

In the beginning, I kept mum about "T" burners, because they are Frosty's design, and therefore, Frosty's business; it was a question of respect. I have very little to say about Larry's "Z" burners for the same reason. However, it has become obvious over time, that the dynamics of his burner is utterly different from any of my designs. It isn't just a question of experience that is lacking, but nearly two decades of working with completely different flow dynamics. My every instinct is out of phase with his burners. You need to talk to the burner's designer, who has spent two decades refining his knowledge, and equally important, his feel for them.

Going out on a limb, I would suggest that the decreased space within the forge, will change the amount of back pressure on the burner, but even there, flow dynamics between my burners and his are very different.

[Frosty]

Things are bouncing around enough I have trouble keeping track, I try to stay out of this one when possible, same reasoning as Mike's. 

I need to see some pics to judge. There's no telling if what you describe is what I'll see. T burners are much higher velocity than Mike's so there will be more dragon's breath but it shouldn't be excessive. 

Pics, one in the door, soon after lighting and one when hot. A pic or two sideways across the door in a dim shop so I can see the exhust gasses, dragon's breath.

Frosty The Lucky.

 

[Square Nail]

Sorry all, didn't mean to ruffle any feathers or go where I shouldn't have gone! I should have put all this on my Forge Build post and not this one! Sorry Mikey, I didn't mean to put you in a bad spot. I will continue this on the other post. 

Thanks again truly for everyone's help and support!

[Mikey98118]

 

Reducers for linear burners

Concentric reducer fittings are pipe parts.  Concentric reducers come in two kinds; threaded, and but-weld. Threaded pipe fittings are becoming scarce and cheaply made; this contributes to squat shapes (poor flow dynamics), and misaligned threading jobs, which are notorious for being out of axial alignment. If you want to end up paying a lot in time and money for a second rate burner, threaded fittings are the shortest rout there.

Stainless steel pipe fittings just scream "expensive"! But the greatest factor in the cost of pipe fittings is how fast they move off the seller's shelf. Stainless steel but-weld parts outsell mild steel parts so much that they cost about the same; sometimes a lot less.

You may need to lay out three reasonably equidistant threaded holes near to the small end of of the fitting. I like to use stainless steel socket set screws to firmly hold the burner's mixing tube within the small end of the reducer,  (but these screws can be changed out later, so use whatever is convenient to begin with).

Mechanically joining the parts together has several advantages: First, it reduces the size of the inside diameter of the mixing tube in relation to the large end of the reducer fitting. In a fan blown burner the ratio of the fan blade to the inside diameter of the burner should be no more than 3:1, to avoid dangerous back pressure at the reducer/fan assembly joint. But in a naturally aspirated linear burner  3:1 is the smallest acceptable ratio, and  4:1 is much better. It is desirable to be able to separate the reducer from the mixing tube when aiming, and later in adjusting, the gas jet. Finally, being able to change out mixing tubes can allow a single burner to be reconfigured as different burner sizes later on, as you find desirable.

Note: You can help adjust ratios with the thickness of the mixing tube's wall, and by grinding the inside of the large opening in the reducer fitting to form a long inner taper, which works much better for air flow than a short inner bevel. by inserting a beveled spacer ring between the reducer's small end, and the mixing tube, can be made to fit up properly with even smaller mixing tubes.

The mixing tube should be "seamless"; otherwise you may need to grind down the inner weld bead which is often found in cheap pipe.

Steel tubing has better tolerances than are found in pipe.

The three screws (which are recommended in the reducer fitting) can be reduced to a singe screw, IF the mixing tube and reducer can be made to fit snugly together buy twisting (rotating) the two parts against each other. On the other hand, a really sloppy fit could require six screws.

The mixing tube's  end must be beveled at least sixty degrees on its inner wall, to facilitate air flow; this doesn't need to be done at the beginning of construction, but can be  left as final improvements to bring a weaker burner up to full power.

As a general rule the length of your mixing tube should be nine times its inside diameter; ten diameters can be used to insure a smooth flame in hand held burners, and eight diameters can be used to shorten a flame, in case of limited available room for the flame path.

Do this much, and then I will provide further instructions.

[Mikey98118]

AxL said

"So if I understand you correctly, since the large end of the reducer is 2", the inner diameter of the tube i use should be 1/2" (for a 4:1 ratio)? And the length of the tube, by rule of thumb, should be 4.5"? I will likely turn the tube on a lathe to get the dimensions just right. 

I have different sizes of MIG tip available, in metric. 0.8mm (0.031") and 1.0mm (0.039") Not sure what it corresponds to in actual size. What would be you recommendation? I'm running approx. 2.2 psi/150mbar off my regulator.

I'll try to get started on the construction tomorrow and come back with pictures."

Thanks!

I have already perfected 3/4" linear burners using 2" x 3/4" reducers (see the MIG tip upgrade on Ron Reil's burner pages). You don't always need to reach for theoretical limits in the parts, to achieve your goals. You just need to get close enough to provide the mixture flow needed to build a very hot burner.

However, if you don't want to weld or braze the mixing tube in place, you will be forced to change reducer fittings, or settle for a 1/2" burner. Welding the two parts together will require #309 welding rod. Brazing the reducer and mixing tube together will require stainless steel brazing flux and 50% or greater silver content filler alloy. Also, you will have to use a special flat washer to insure that the gas jet is trapped dead center in the the mixing tube, during mounting of the assembly and saddle fitting, or else use a wooden  handle with a 1/4" hole in one end (to hold the MIG tip centered), to do so.

Use the actual inside diameter of the pipe or tube you use; not the nominal call out size. Also, you would use the full length of the mixing tube, if it slides inside of the small end of a reducer fitting, but only the remaining distance beyond the small end of the fitting, if it is attached to it, instead of trapped within it.

[Mikey98118]

A 1/2" size burner would need a 0.8mm (0.031" orifice size), long MIG contact tip. A 3/4" burner size would need a 1.0mm (0.039" orifice size) long tip. However, use of schedule #80 1/8" gas pipe will improve gas flow between pipe and tip enough to make short contact tips acceptable.

 

Understand the the actual orifice size of a MIG contact tip is always several thousandths of an inch larger that the tips designated size, which only concerns the welding wire it is meant for use with.

[Mikey98118]

The mixing tube on linear burners

While threaded pipe reducers have been used extensively to build linear burners over the last thirty years, they were the choice of convenience. The first linear burners used butt-weld pipe reducers to achieve the best possible air flow. But, threaded reducers didn't require any welding or brazing skill, and where also cheaper. Unfortunately, because steel water pipe is being marginalized by copper and plastic tube, threaded steel reducers are also being used less often, and so they are overwhelmingly being supplied as crude imports. Butt-weld reducers are a lot more expensive then threaded ones, and so mild steel reducers are likely to cost as much as stainless steel reducers.

Usually, the mixing tube will end up sliding into the small opening of a butt-weld pipe reducer fitting, or screwing into a threaded reducer.  But welders and brazers attach them unto the end butt-weld pipe reducers, or any other cone shaped part. Most reducers have part of their inside that will run parallel to the outside of the mixing tube, at some point.

The inside of the tube end is beveled to maintain good gas/air mixture flow, and the tube is pushed as deeply into the small end of the reducer as it will go before a gap forms between tube wall and reducer opening; this is the point where the tubes eight diameters are measured from. If the tube is welded or brazed onto the reducer the eight diameters are measured from the point within the reducer, where its inside diameter matches that of the tube. When welding or brazing the mixing tube onto the reducer, you need to use a square to make sure the tube's end is completely square to the reducer's end. The two parts are held tightly together with a length of allthread, two nuts, and two flat washers. Be carefull to keep the inside surfaces inline, two end up with a smooth transition point in the joint.

Note: The size of the gas orifice is a function of of the mixing tube's inside diameter, and nothing else.

[Mikey98118]

Flame nozzles

We various experts had agreed that a 12:1 expansion taper was best on a flared flame nozzle; this supposition is being sorely tested and battered today. Apparently, how much taper is right for a burner depends on the flow dynamics of that burner. I found these tapered nozzles to give weak performance on my burners, and replaced them with stepped nozzles eighteen years ago. Stainless steel was found to last much longer than mild steel nozzles; and #316 stainless lasts longer than #304 stainless.

The nozzle diameter should be approximately the equivalent of two schedule #40 pipe sizes. One pipe part is used as a spacer tube of about 1" long. The stainless steel nozzle can be made of the next larger #40 pipe size, or a nearly equivalent stainless steel tube with the right inside diameter chosen from a pipe chart. For a 3/4" burner that would mean a 1" or equivalent pipe or tube for the spacer ring, and a 1-1/4" stainless steel pipe.

A 1/2" burner would use a 3/4" schedule #40 pipe a or equivalent tube for the spacer ring, and a 1" stainless steel pipe for the nozzle.

Note that stainless steel pipe actually costs less than equivalent tubing from Onlinemetals.com. They are pleased to receive small orders, and will cut parts to size for a small fee.

How to determine length of the flame nozzle: These nozzle are designed to run back and forth over the mixing tube to help tune the burner. As a rule of thumb the amount of nozzle overhang past the end of the mixing tube will slightly exceed the inside diameter of the nozzle. To that distance add the width of the spacer ring and 1/4" for slop; the sum of these figures are the length of the flame nozzle.

In the past I have used a ring of equally spaced stainless steel socket setscrews to hold the nozzle in position, and even two rings of them if my parts were a sloppy fit. It is necessary to force the flame nozzle into perfect alignment with the mixing tube; otherwise the flame will be forced off center of the burner; this is a destabilizing factor; avoid it.

If your parts are good enough that twisting the slightly out of round flame nozzle on the slightly out of round mixing tube provides axial alignment, then as little as a single screw may all that is needed.

[Mikey98118]

The gas assembly and saddle

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 burner’s 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.

Note: if you live somewhere that doesn't provide these parts and materials, compromise by substituting whatever heavy wall tube has an inner diameter that can be handily threaded for whatever MIG contact tip you can find. Then run whatever external thread you can substitute for IPS, and simply stop short of the area at the end of the tube that contains the internal thread for the MIG tip.

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 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.

Because the gas tube has outside threading, you can also cut out aluminum plate with a hole saw, to make a choke plate, 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 other burner designs, which run hotter than I can otherwise account for.

 

[Frosty]

I think if a person is going to machine a linear burner on a lathe they forget plumbing entirely. Start with a billet, turn a proper intake, trumpet bell to the throat 1/2" in this case. The transition should resemble the leading edge of a wing then taper the tube at a maximum rate of 1:12 or coincidentally 12% for 8x the throat diameter. The throat transition from intake to tube looks like a wing either direction.

If you need a model, search out "Fisher Burner" a Fisher is a jet ejector but the geometry of the burner from throat to exit is the same.

Old school commercial production spun them from tubing. In smaller cheaper or lower performance versions like Fisher Burners they were stamped in two halves and crimped together.

I believe the recent success of bell reducers as nozzle flares is because they're low velocity and the bell is little different than exiting into the forge.

Frosty The Lucky.

 

[Mikey98118]

I spent several months investigating Bunsen, Fisher, and Meeker burners four years ago; the idea at the time was to use their controls as a way to reduce the costs of building equipment burners; it was a bust, because their needle valves are only meant to withstand ounces of gas pressure.

I gathered about half a box worth of used burners off of eBay before the economy recovered enough for their prices to rise too much. It was only natural to run the original burners: The result seemed to be unsatisfactory, at the time. However, after seeing a "T" burner running with just the right flame nozzle (the 2009 thread), I have been forced to take a closer look at the obvious

Lab burners and old wasp-waste kiln burners--as they are configured-- are far less powerful than even a Reil burner. BUT, I believe that small changes in those designes could produce uniquely appropriate equipment burners; they present a wide open opportunity for someone to perfect a powerful new burner.

Why? Because just a little narrowing of the taper, which is designed to slow the gas/air mixture down in a lab burner, could be speeded up enough to turn the burner upside down, and produce enough positive pressure in the flame to overcome buoyancy, and create a very hot, very slow, and very SHORT flame for top dead center burner positioning in square forges.

Just like recent radical change in accepted tapers for flame nozzles, we again see that everything boils down to a question of balance. 

That should read "wasp-waist" burners.

[GrumpyBiker]

I have a question that I'd like conformation on.

On a burner I've read that the flair isn't needed if it's to be inserted in a forge.

Is that correct?

Or if it's possible should a flair be left on ?

Also there seems to be a lot of opinion of how far back the burner should be set from the inside of the forge.

Is there a hard rule for that?

 

 

[GrumpyBiker]

Okay , strike my last post....

I have read & re-read this last page three times in an attempt to "get it".

I'm sure it's due to my total lack of experience but it seems that not only is each burner style it's own animal but how each style is tuned is dependent on a number of factors as well.

So much so that my above question would have to be answered with "well that depends ".

 

Am I wrong to assume that each burner also has to be tuned to each specific forge it's placed into?

That the shape & size & materials the forge is made of also greatly effects burner performance?

I ask because I think a lot of us newbies run towards the idea of a "plug & play" set up.

The foolish idea of placing an order for an entry level forge & burner and are disappointed when you can't just hook it up & go.

 

Everything is much more involved that it appears on the surface.

Glad there are folks who spell it out for people like me who at times feel "in over their heads".

So much to learn & consider before you can get to the point where a person is ready to move & shape metal properly.

[Mikey98118]

Grumpy Biker states "Okay , strike my last post..."

Well, no; your last post brings up a couple of questions well worth answering. the answer is that a flame nozzle isn't a necessity, when the burner is placed within equipment, but it is always worthwhile.

"Also there seems to be a lot of opinion of how far back the burner should be set from the inside of the forge." Yes, there is a lot of different opinion on just how far is far enough. I like to keep it 1" deep within the insulation, and to keep the insulation 1/4" away from the nozzle, all the way around.

Am I wrong to assume that each burner also has to be tuned to each specific forge it's placed into?

You are right.

That the shape & size & materials the forge is made of also greatly effects burner performance?

You are right.

I ask because I think a lot of us newbies run towards the idea of a "plug & play" set up.

The closest you can come to "plug and play" is to pick tried proven burners and forges, and then follow their directions exactly; otherwise you must learn a whole lot more, in order to do things your way.

"The foolish idea of placing an order for an entry level forge & burner and are disappointed when you can't just hook it up & go."

That's because entry level forges are a good long way from "plug and play."

"Everything is much more involved that it appears on the surface."

You are right.

Glad there are folks who spell it out for people like me who at times feel "in over their heads".

Nothing worth doing is ever easy.

So much to learn & consider before you can get to the point where a person is ready to move & shape metal properly.

I used to tell guys that steel work just amounts to mastering a thousand simple tricks. Of course I always assured  my bosses that is was brain surgery and rocket science.

It is still "the best of times and the worst of times." It's is entirely up to you which one you see, when you look back upon it in your old age...

 

[Mikey98118]

20 hours ago, Mikey98118 said:

Well, no; your last post brings up a couple of questions well worth answering. the answer is that a flame nozzle isn't a necessity, when the burner is placed within equipment, but it is always worthwhile.

The other side of the coin is that,because it is isn't a necessity, the flame nozzle can be treated as an add on; it doesn't have to be made immediately, so long as as the forge is made with its eventual inclusion is kept in mind. 

Furthermore, the forge insulation can be used as a flame nozzle, if it is rigidized, and a hole of the proper diameter is coated with refractory; thus acting as a temporary flame nozzle.

[Frosty]

Heh, heh, heh, you should've shot me an email Mike I have a box of Bunsen and Fisher burners in the Connex, I grabbed them as the lab tossed them out. The taper on a Fisher is more that 1:12 but the burner isn't intended to burn propane, the conversion kits cost as much as the burners. I think we discovered the same thing about the same time. 

Grumpy: You have it right, any home built device is going to have it's own character propane burners have a LOT of individual character. The 4 burners on my shop forge were made on my lathe using the same recipe. Everything went into the forge as built with pretty close tolerances 0.005" IIRC. The rest of the variances were in the pipe, mig tips, etc. Each one of those darned things had to be tuned individually, 3 work as expected but one is a golden BB. That puppy melted the 3,000f split hard fire brick I put in for a floor. It no fooling melted a spot where the flame impinged about 2.5" dia. Once vitrified fire brick starts loosing it's melting temperature the molten puddle is closer to 4" dia. and contains all sorts of debris ad yes welding flux has lowered the ipressivenes of it all.

But yes, every single burner you make even if you follow proven plans is going to be it's own thing. I remember high school lab and the teacher walking around adjusting every Fisher burner every session. Even the commercial stamped in the same dies burners had their own characters.

Frosty The Lucky.

[Mikey98118]

Frosty,

You have thought about how zirconium silicate/ Veegum refractory could be used to make a practical "slip cast" burner, yes? this could make it practical for people to create tapered burner shapes at home with nothing more than hand tools.

[blacksmith-450]

My Mongo Burner

I started with the recipe of the mongo burner found on the WEB and adapted it to a 3/4 format.

Parts List :

• 3/4 to 1 inch reducer
• 3/4 X 8 inches nipple
• 3/4 to 3/4 connector
• 3/4 cap
• 1/8 NPT nipple 2 or 3 inches
• 2 X Fitting 1/4 NPT 1/4 tube
• Mig Tip .023 (brass welded on fitting)

I drilled 4 X 1/2 inch holes at 1/2 inch from the threads.

When I had a neutral flame, I welded the 1/8 nipple in place rather than using a set screw... yes, I lose the possibility of adjusting it but.... ?  If my flame is steady, why play with it ???

[Frosty]

On 8/15/2017 at 6:19 PM, Mikey98118 said:

Frosty,

You have thought about how zirconium silicate/ Veegum refractory could be used to make a practical "slip cast" burner, yes? this could make it practical for people to create tapered burner shapes at home with nothing more than hand tools.

It's tempting Mike but Veegum  takes a long time to dry. The thrown kaolin vessel with 0.25% Veegum took a week to dry enough to bisque fire and it looked almost paper thin. How would we get slip to dry, even with the water sucking molds? Seriously, would slip dry at all in anything like a reasonable time? Weeks, months . . . ?

If we came up with a high temp ceramic burner we could retire. . . AGAIN!

Frosty The Lucky.

[Mikey98118]

Frosty,

By "slip dry" I was only referring to how able to be easily cast this formula should prove. I suspect that vibration of this formula would make a neat end run around the settling out problems inherent in typical refractory formulas containing sieved grog. Being able to vibrate without settling out should not only allow the complex shapes of slip casting to work, but also allow much less water content to be used. This is the way I plan to use the formula to make tile, crucibles, and multi flame nozzles.

17 hours ago, blacksmith-450 said:

My Mongo Burner

I started with the recipe of the mongo burner found on the WEB and adapted it to a 3/4 format.

Thank you for posting information and a flame photo of your latest burner on this thread. I think "seeing is believing" for most folks, and the more kinds of successful burners they see, the better