Mikey98118

With minor exceptions (some forges are deliberately designed to create a hot spot) that is correct. However, flame impingement is pretty unlikely with ribbon burners, because their flames are so short. I'm sure that someone somewhere could "push the envelope" enough to create a problem, but they would need to push real hard However, Frosty probably would advise Toolshed to pay more attention to his exhaust arrangement. Perhaps something smaller and longer might serve his purposes better. We must always watch out for a buildup of back-pressure in long narrow forges...

Frosty, is this the information you wanted to dredge up? None Stabilized zirconium dioxide (ZrO2; AKA zirconia) has three phases: Mono-clinic at less than 2138 °F (1170 °C), tetragonal between 2138 °F and 4298 °F (2370 °C). The transition between the first and second phase creates enough expansion to prevent it being used in hard refractory products, unless it is stabilized in the cubic form, or in its more useful partially stabilized tetragonal form. A small percent of calcium, yttrium, or magnesium oxides can be used to partially stabilize zirconia; cerium oxide can also be used, but is too expensive for home-built equipment. Further high temperature manipulation can form fully stabilized zirconia, but adds further expense. Zirconia has very low thermal conductivity, yet very high luminosity when incandescent temperatures are reached. These two facts combine to make it a preeminent heat barrier. Because of the high luminosity, it can be used as an effective method of heat transference on high temperature casting crucibles, when applied in very thin coatings (.040” or less), and yet thicker coatings can be used to “reflect” heat through re-emission, while providing insulation that only improves as heat levels rise. When it comes to various heat barrier coatings, very fine particles of zirconium are desired, because the finer the particles the higher re-emission percentages go. Government sponsored experiments in the nineteen-sixties showed that phosphoric acid was able to hold none-stabilized zirconia onto heating surfaces despite phase change resizing; it was an important find—back then. But stabilized zirconia is much cheaper than it was in the past, and so this more expensive product is the better choice for tough heat barriers, and nowadays for some castable refractory crucibles; clumps of it are also used as insulation between crucibles and wire windings in induction furnaces. Zirconia based refractories, and alumina ceramics with stabilized zirconia included are well known for thermal shock resistance and resistance to erosion from incandescent liquid metals. Note: Drying can produce up to 4% shrinkage in slip cast zirconia refractories, and firing at 3452 °F (1900 °C) will produces up 15% contraction; factors to be considered when planning structures made of it. Zirconia is available for use as grog, and is an effective loose insulation for very high heat environments (think of it as being like Perlite on steroids). Zirconia also comes as stabilized ultra-high temperature porous insulating brick. Zirconium silicate: Hobbyists concoct a tough sealant coating that is also a high-emission product bt purchasing zirconium silicate flour from a pottery supplies store, and mixing it with bentonite clay powder; this is practical, because it does not go through phase shifts. Zirconium silicate, while very tough is only rated at about 70% heat reflection; it is also very resistant to borax, and an economical choice. Zirconium silicate can be either a coating or a hard refractory layer, depending on the amount of bentonite clay, etc. it is mixed with. One of the hobby blacksmiths on IFI makes a slurry of Zircopax (a brand of zirconium silicate) mixed into colloidal silica (AKA fumed silica) and a little water; he also uses this mix for shell casting; he suggests mixing it to about the consistency of latex paint, in a clear lidded jar. The Zircopax will settle out, once you stop stirring every few minutes, and cake on the bottom of the jar, with the silica and water remaining in solution over it; until it is broken up with a butter knife, and thoroughly remixed back into solution. When combined with silica as a binder, I believe the overall performance of Zircopax in thicker layers will prove to be considerably higher than 70% heat reflective, since the other part of its molecular structure is clear natural silicate, which will pass light rays with very little interference, and since its re-emission mechanism is radiance, I believe its overall performance in thicker layers will prove to be much higher than it is rated at. Remember that each layer must be fired before the next layer is painted on. Tony Hansen, of Digital Fire fame, uses Zircopax as both a coating and a solid refractory, very like clay, but good to very high temperatures, and highly insulating; two qualities that mere clay lacks. Mr. Hansen mixes it with Veegum T (a smectite clay) as a binder and plasticizer. A mixture of 97% Zircopax and 3% Veegum can be molded into structures, as easily as potters clay. A mixture of 95% Zircopax and 5% Veegum provides a hard tough heat reflective coating for other refractory structures. Mr. Hansen has also used his formula to created his own 5mm thick (just over 3/16”) kiln shelf, which he states “will perform at any temperature that my test kiln can do, and far in excess of that.” It consists of 80% Zircopax Plus, with 16.5% #60 to #80 grit Molochite grog, and 3.5% Veegum T; he states that the mixture is plastic and easy to roll out, with 4.2% shrinkage, with 15.3% water added, but suggests that you dry your forms between sheets of plasterboard, to prevent warping. Firing to cone 4 produced 1% shrinkage, and left his shelf only cinder bonded. Firing to yellow heat will produce further shrinkage, but strengthen the final product; this has about the same thermal shock resistance as high-alumina cast refractories. Avoid uneven heating by setting your forge or kiln up to work as a radiant oven. Read about Zircopax at: https://digitalfire.com/material/zircopax Read about Veegum at: https://digitalfire.com/material/1672

Frosty, I agree with you completely...as an end goal. However, cheap hard firebricks make good "training wheels." The thing I like best about "add-ons" (everything not built into or unto the forge), is that people can always up date later. I kinda like luring folks down to the deep end, before they know it's getting serious Mikey The Sneak

I just might remember, if it had been five or six days ago

Some final rambling may do him further good, Frosty. The first thing both old and new photos seem to be showing, is complete combustion. The color limits of of photos being what they are, we would need a side view of the exhaust gases before I would count on that. But, if combustion isn't complete it is close enough to it. The second thing is; that flame shape is probably do to insufficient control of the flame, from inadequate or missing flame retention nozzles. I believe this lack is permitting the flame to touch the ragged edges of the forge's burner ports. If his flames turn out to be slightly reducing, then this all amount to a storm in a tea cup. Either way, his next move should not be further tinkering with the burners, but starting to control what goes on in his forge, with movable exterior baffle walls. I suggest hard firebrick for them. The rear bricks should be right up against the exhaust opening. The forward brick wall should start out at 1" away from the opening, with the bricks being moved apart only enough to allow his parts through. How wide the gap between forward brick wall and forge ends up, will depend on how hard he is running his burners. If he wants to use the forge for heat treating, he must be able to fine tune its internal atmosphere--not just the burners; they are only half of the equation.

Totally. My first burner designs were all linear burners. I spent six months trying to suppress the idea of high speed tube burners, before circumstance and curiosity won out, and Mikey burners happened. A quarter century down the road, I have lightened up about having my druthers, on account of that serendipity thing.

Have we gotten switched around? I'm saying "keep it simple," and your saying "do it slick." Next thing we know, you'll be making hilarious typos, and I'll have to think up clever jokes about them; its just all backwards, to the way things are meant to be...

What is new in my imagination is totally off topic, having lots to do with better seeing of torch and burner work; not in producing burners and the forges they heat I have also been interested in new methods of making multi-flame flame retention nozzles, using drilled stainless steel plates in flame retention nozzles. Two different builders on IFI have built multi-flame burner nozzles, employing stainless steel drain filters; both of them succeeded handily. Drilled stainless steel plates should be the next step, as those thin drain filters cannot last long. So, this idea has been circulating in my murky depths for a couple of years. This leads to the next question, which is the best method of holding such a plate in, or on, a torch nozzle. I'm leaning toward on, not in. On what then? On pipe reducer fittings, which provide the extra internal area to create a plenum chamber, and also a handy lip to drill and thread for face screws. Repurposing the inventions of better men, for my low schemes doth make me grin, forsooth

It is only old news to us. It's the latest thing to newbies I would rather rehash the burner's other end--its nozzle--especially various multi-flame nozzles. I suspect that this is where coming burner improvements will happen, for the next few years.

It takes a variety of burners to make a dog race. If somebody wins the race, things suddenly get boring! Besides, no one burner design is best for every purpose.

Auto-darken welding filters: Unlike the various types of solid glass (and polycarbonate) welding lenses, an auto-darken welding lens has a limited-service life, determined by how long it take for its rechargeable battery to wear out; some of the more expensive auto-dark lenses have replaceable batteries. However, that only affects an ADF’s dark state. its light state (AKA clear, or bright state) is built into the front glass sheet (called a UV/IR interference layer) on every auto-darken lens; also, the light state filter strength (shade #2.5, #3, #4, or #5) is built into the ultra-thin metallic coatings on that glass mirror’s front surface. The manufacturers choice of coatings on the interference layer also affects your view. Typically, there are six coatings of aluminum oxide and five layers of silver oxide. Some interference layers include a gold coating on top of the silver and aluminum coatings. If you see a magenta color in the front surface of an auto-darken filter in photos, its coatings provide a green view, which is no different than a standard ANSI filter of the same shade as the filter’s clear state. If you see a smoky, or light blue surface in photos, you are probably looking at what is called a true color auto-darken lens. You can add colored polyester film, or a thin acrylic sheet behind such a filter, to manipulate your color view as desired. Some gold-plated filters give a blue view, which cannot by changed. If you see a red surface in photos, it gives a red view, which cannot be changed. You will not be able to see a blue torch flame through this kind of dichroic filter. The advantages of a true color ADF in gas welding, can also apply to arc welding. Blue puddle auto-darken lenses and red auto-darken lenses are by far the most expensive kinds, but nothing prevents you from inserting a color film behind a true color ADF, to achieve these same expensive views. The best part about employing ADFs with colored polyester filters, is that you can cheaply buy a shade #3 visible light rating, while every one of these lenses limit UV and IR transmission to no more than is allowed in their highest rated dark states; that starts with shade #10, and goes all he way to shade #15 protection.

I think that Diamondback Forge upgraded their method of building the body of their forges, and cheapened the materials they insulate them with. These changes allowed them to drop the price of the entry level single burner forge, down to the range of all those cheap imported forges. I suggest you look into one. You can always upgrade the insulation back up to ceramic board, when the ceramic wool needs changing in a few years

To do a good job of silver brazing burner parts together, and silver brazing parts unto forge bodies, you need to have a good view of the work. Green ANSI rated welding lenses, are just fine for use in torch brazing, welding, and cutting on copper, brass, and steel alloys, and are low cost. Unfortunately, you will not find one for sale in lighter than a shade #4. For silver brazing shade #3 provides the right view. However, the oldest (and therefore cheapest auto-dark lenses, which appear magenta in photos of their lens faces) provide shade #3 green views, with the same blocking of UV and IR of a glass shade #10 welding filter, in their clear states. If you look under unigoggle filters, at Amazon.com, you can pick one up for $10 to $12.

Continuing off topic...I assume that the black oxide surface will provide good protection against further rusting?

Agreed; however the forge gets more than hot enough for any but production line work. Overall, I think multiple flame burner heads are the way to go. It hurts me to say that, since rock and roll is my personal druthers

Well, we could type out a couple of pages, trying to exhaustively answer your question. But the short answer, for a whole lot of reasons, is look into buying a single burner Diamondback forge, for what your state your goals are

Thanks Latticino. That is a pretty good answer to what is going on

Using ceramic wool insulation and rigidizer Even the cheapest grade ceramic fiber blanket does not melt below 3200 °F. Product temperature ratings come from the level of heat that fiber products will withstand without massive shrinkage; this should illustrate the importance of locking the individual fibers in position by rigidizing; it also demystifies the seemingly magic protection conferred by a relatively thin coat of heat reflector, such as ITC-100, or Plistix 900. Ceramic fiber products need both rigidizer and finish coatings to do well in today's gas forges; this is because better burner designs and smarter forge designs create much higher internal temperatures than were common in the past. Rigidizer is especially important, because if you want your insulation to last, it must be prevented as much as possible from shrinking. On the other hand, between employing 2600 °F or even 2900 °F rated ceramic fiber insulation and rigidizer, you can toughen the secondary insulation layer in your forge or furnace enough so that it should stand up well to the heat that will leak past the high emission coating (AKA IR reflector) and thin hot-face layer (typically Kast-O-lite 30 for many years. Rigidizer also helps support thin flame face coatings. There are products like Plistix touted as heat reflectors, which make very nice surfaces on which to paint more effective high-emission coatings. You do not want to use thick fiber insulation layers, which tend to ripple when placed inside of curved surfaces; instead of a single 2" thick layer of ceramic fiber, place the blanket in two 1" thick layers. Ceramic fiber blanket will easily part into thinner layers via delamination between layers. Rigidize each layer after installation, and heat cure it, before installing the next layer. Finish forming burner openings before rigidizing each layer. remember to cut them just a little oversize so that they allow the burners to be moved without suffering damage. Note: When first wetted with rigidizer, the blanket sags somewhat; this makes an excellent opportunity to push bumps flatter on its surface, and then heat them up to red incandescence with your burner, before they can raise up again. This way, you can smooth the first layer, before placing a second layer over it. Continuing this trick on the second layer will smooth its surface, before adding a flame face layer over it. Rigidizer is colloidal silica (just fumed silica, which stays suspended in water) and common everyday food coloring (to allow you to visually judge how far it has penetrated); this product is easiest to dispense by spritzing after you mix up your own. But you can always pay through the nose for it, already mixed with water and a dash of food coloring, from a pottery supplies store. I bought my fumed silica powder through eBay and got free shipping, because its weight is negligible. Ceramic fiber products are so porous that water runs right through them, unlike solid refractory, which must be slowly dried out, and then gently heat cured to prevent damage from a buildup of steam pressure. So, ceramic fiber can be "cured as you go," which means that nothing prevents you from slowly rotating a layer of blanket on a curved surface, like a casting furnace or tube forge, spritzing the rigidizer unto each area that is laid flatter by the weight of the liquid, using your burner (turned down low and constantly moving over the wet fiber), to stiffen the blanket into permanent shape, and then moving on to the next area at your convenience. After creating a smooth stiff surface inside the structure, you can install another layer over it, the same way. One of the advantages in completely soaking the blanket through is that both layers will bond together. Any excess rigidizer that soaks into the first layer will run right over its fiber’s surfaces by capillary action, the same as it did the first time, causing no clumping to degrade the insulating value of the first fiber layer. The whole process is nearly goofproof. But it is still possible for a complete idiot to burn himself with the escaping steam that will be created, during firing. If you turn a high-speed burner on at maximum while holding still over one spot, it is conceivable (but quite unlikely) that you could even shrink a patch of fiber. What keeps Murphy’s Law from messing up your efforts? First, the fiber is partly alumina, and partly silica; the aluminum oxide (Al2O3) pretty much prevents it from melting, while the silicon dioxide (SiO2) bonds beautifully to the glass surface left from the old rigidizer. Secondly, the individual fibers in the blanket are very thin, which maximizes capillary action of a liquid across their surfaces. During heat curing, the colloidal silica that has wet every bit of fiber becomes a permanent vitreous outer layer on them, which creates welded joints everywhere the fibers cross each other. This glass sheathing is permanent. More rigidizer applied over it simply adds another ultra thin layer after the next heat. Glass (silicon) is heavy, yet a quart jar of foamed silica (which forms colloidal silica in water) is so light that the plastic container is heavier than all of its contents; this is because colloidal silica particles are so small that the main ingredient in the jar is air. Their tiny size is also why the powder will melt unto the ceramic fiber surfaces, this one time, at red heat. Afterward it remains solid at yellow heat. Consequently, every layer of silica sheathing on the ceramic fiber remains so thin as to leave the insulating ability of the blanket unchanged, even after repeated applications. Note: If you do not completely dry the rigidized blanket before coating the blanket layers with sealant, it can still create a steam pressure problem, damaging the seal coating. So, drill a 1/8” hole in the bottom of the equipment’s steel shell, as a pressure valve, and seep hole. You can buy colloidal silica rigidizer at some pottery supply stores, but being mostly water, it is not cheap to ship from online sources; in that case you are better off to mix your own. Commercial solutions usually contain about 1100 grams of colloidal grade silica per liter of water. A liter is just over one quart (just under 34 ounces), if you want to use a kitchen measuring cup. One easily found and economical source of colloidal grade silica is fumed silica, which can be purchased from eBay, Amazon.com, and many other suppliers. To assure receiving the right form of fumed silica, input “rigidizer” in your Google search. Also make sure the product says powder; so that it’s not already mixed with water, if you don’t want to pay ignorance tax to the unscrupulous. Unlike sodium silicate, this product must be fired to take a permanent set on the ceramic fibers. Never allow this or any other colloidal solution to freeze, or it will clump together, and be ruined. On the other hand, measuring amounts is not needed. Commercial solutions commonly contain thirty percent fumed silica in solution with water. If you make your solution too thick to spritz, just add water. Too weak? Add more fumed silica. Hard to determine how well it is penetrating the ceramic blanket? Add food coloring.

Did this ever get resolved?

Thanks for cluing me in, Jerry. It does sound like they have improved the process a lot (sill plenty bad enough, though).

Ouch! Sorry to hear it. Just got out of the hospital too. And people expect old age to be boring...

Michael to Jerry Hey, I haven't heard a Frosty joke in months. I need my fix!

Materials needed to make a homemade rivet nut setting tool (A) One grade #8 (SAE standard) steel socket head cap screw or bolt, of the same thread size as the rivet nut, and at least long enough to accommodate every part on the tool, and still engage all the threads on the rivet nut. The reason to use a high strength cap screw or bolt, is that it is much tougher than a low carbon mild steel cap screw or hex bolt; extra tensile strength is best, when using a small diameter cap screw or bolt as part of your homemade rivet nut setting tool. Mild steel screws and bolts have about one-fourth the strength of high-grade screws and bolts, which are made of medium carbon content alloy steel, which has been quenched and tempered for maximum tensile strength. (B) Two brass flat washers, to sit between to the flange screw and the head of the high strength bolt is helpful (providing a bearing surface). The washers simply help the bolt to turn more smoothly. C) A flange nut that is drilled out to a larger size, to freely slide over the tightening bolt’s thread (it is there to be held in place by a wrench; this prevents the rivet from being turned by the revolving bolt head (you do not want the rivet nut to start turning in the hole, while being crushed into shape). (D) An open-end wrench for the wrench to keep the drilled-out flange nut still, and a and a box wrench to turn the bolt or cap screw’s head with. Drill a hole in the mounting plate that is as close to the rivet nut’s outside diameter as is feasible. A snug fit is ideal. The more gap there is between the rivet nut and the hole, the harder your job of riveting will become. The less gap there is between the rivet nut’s body and the hole it gets pushed into, the sooner it starts becoming trapped in place (and no longer able to turn under the tightening bolt). Slide two brass flat washers onto the bolt. Slide the drilled-out flange nut onto the bolt, with its locking side facing the rivet nut. Screw this assembly unto the rivet nut, just finger tight. Push the rivet nut into the hole in the mounting plate. Place the open-end wrench on the flange nut, and the box wrench on the tightening bolt. Turn the bolt head until the rivet nut is securely fastened onto the mounting plate, using the open-end wrench on the drilled-out flange nut to keep it from turning, too. You can find several videos of this process on the Net, with variations in nut and flat washer choices. Fender washers come in a limited number of center hole sizes, but it is not much work to drill or grind a fender washer’s center hole larger, to fit a rivet nut diameter. Grinding is an easy way to increase a hole in a sheet metal mounting plate, a little larger than the largest bit that can be chucked in your drill motor.

Today's gas assemblies for today's linear burners Air flow into a burner’s opening can be forced through mechanical means (a fan or air compressor), or induced by the low-pressure area created with a fuel gas stream (Bernoulli’s Principle). As the air that is passed through a linear burner’s cone shaped air opening, it gets spun. Swirling air does the best job of mixing with a fuel gas for the least drag on mixture flow. If you want complete combustion in your burner’s flame, that takes good fuel air mixing. Thus, pipe reducers became the air entrances of choice on early burner designs, and are still the favorite choice today. About half of those deigns plumbed the fuel gas, in what we call cross pipes: their advantage was that they could be used to feed multiple burners. The other half of forge deigns plumbed each burner straight down the burner’s air entrance, but most of them were hold rigidly in one position. Movable gas pipes, with gas orifices that could be placed exactly at the right distance from the entrance to a burner’s mixing tube, was the next logical improvement. Which brings us to methods of holding a burner’s gas tube in position; this isn’t as simple as merely trapping it at the right depth within a pipe reducer. You also need to ensure that it is held dead center in the air opening, and axially true to it. What constitutes a practical method of mounting your burner’s gas assembly depends on what you employ as a conical shape for its air entrance. And here is where you run right into the problem of choice; or rather the lack there of. Pipe reducers come in limited sizes. Even more limited if you are not a forge manufacturer, who can order parts in quantity. For most individuals, the list of pipe reducer fittings, is shortened further; down to what your hardware store happens to carry. It is exceedingly hard to find reducers with greater than a two to one restriction ratios (2:1). But the acceptable restriction range for burner entrances starts at two and a half to one (2.5;1) and you are best off at three to one (3;1). Pipe reducers only became the popular air entrance choice, because they could be threaded unto a burner’s mixing tube. There is a whole world of other part choices to choose among, from kitchen funnels, to sausage stuffing tubes, etc. However, with the change from thick-walled pipe fittings to stainless steel sheet metal parts, comes the need for a change in how gas assemblies get attached to the burner’s funnel entrance. Mounting plates, made from flat washers, will serve on burners with funnel openings up to two inch in diameters. Larger mounting plate diamaters must be cut from sheet metal. Three air entrances are cut and ground between three ribs, which are then screwed or silver brazed unto the funnel’s opening. An externally threaded brass gas tube runs through the mounting plate’s center hole, and is held there with a special nut. Rivet nuts (AKA Rivnuts) are internally threaded hollow rivets; they are your best choice for attaching externally threaded gas tubes onto mounting plates; they are press fit in place, through deformation, like solid rivets. The main difference is that they are designed to distort easily enough that they can be trapped in place with two wrenches; they will reshape and be trapped into place, centered and perpendicular, on flat washers, or on cut out sheet metal parts. This creates a very strong joint that can be perfectly positioned on the mounting plate. Rivet nuts come in both 5/16-18” and M8 sizes, allowing use of 5/16” x 3/16”and 8mm by 5mm (or 4mm) brass gas tubes to be externally threaded as movable gas tubes in rivet nuts. Both tubing sizes are also thick enough to be internally threaded for MIG contact tips, or 3D printer nozzles as gas orifices. 5/16” hose couplings can then be attached to the gas tube.

Ignition, tuning, and shut-down of Linear Burners These burners are designed to produce high-speed flames, using elevated pressures through small gas orifices. When you hear Somone bragging about their equipment running on one or two PSI gas pressure; that is because their burner’s gas orifice has a much larger hole. There is no free lunch. A popping sound can be made by even a minor gas leak between the a MIG contact tip's thread and the gas pipe—on some high-speed burner designs. Liquid dish-washing detergent in water can be spread on the suspected joint, the gas turned on, and the orifice covered with a finger, to make a soap bubble test for a gas leak at this spot These are hand-built burners; their performance will vary. Some burners might be a little touchy while cold, when you tune them out in the open air; once mounted in equipment, they are far less sensitive; even when cold. Warning: These burners are designed to use LPG fuel gas (propane, butane, propylene) and various LPG mixtures only. Never burn acetylene or hydrogen fuel in these burners; neither gas can be safely employed in any equipment that is not specifically designed for it. Pure hydrogen will embrittle some metals, when hydrogen atoms are absorbed into them, causing cracking. Oxyhydrogen torches are specially made to burn this gas safely. Acetylene reacts with some powder metallurgy formed metals, such as copper, zinc, and silver, to form explosive and shock sensitive acetylide compounds. Therefore, oxyacetylene torches are specially constructed, with this danger in mind. MAPP fuel gas stopped being produced in 2008, when its last plant was switched over to full propylene production. But other MPS fuels (various mixtures of methylacetylene and propadiene gases, mixed with propane, and/or butane, and/or butadiene), are still available outside the U.S.A. Before morning its loss, know that MAPP fuel gas claimed to be a whole fifty degrees Fahrenheit hotter burning than propylene fuel gas, in return for high shipping fees and insurance premiums, because it contained about fifteen percent acetylene in its composition; a losing proposition. Caution: Be careful to decrease the gas flow when switching from propane to propylene fuel inside forges and furnaces; it can easily overheat the equipment too much for standard refractory materials, and are likely to melt a stainless steel flame nozzle right off the end of your burner. Propylene is easier to manage, when these burners are being used as torches, in the open air. You need to combine propylene fuel use with a large dose of common sense. You do not need a full third hotter temperature inside your equipment, but rather a gentle bump of a hundred degrees or two, will usually do the trick. Practice lighting the burner several times outdoors, in a shaded area (propane flames become invisible in bright sunlight). You need to play with the burner for a few minutes, moving that hot nozzle back and forth on the burner’s mixing tube, to produce the sharpest possible flame. I like to leave the long part of an Allen wrench in one of the rear socket set screws, with the screw kept just barely snug, for easy unlocking and movement without burning fingers during this phase of tuning. Place the nozzle’s end so that it is 1/8 longer than the inside diameter the flame retention nozzle, beyond the end of the mixing tube. The right amount of overhang will be somewhere between his point and 1/8” shorter. Turn the gas flow on just a little way, and ignite the burner, immediately turning the gas pressure up high enough to blow any internal flame forward from the mixing tube, into the flame retention nozzle. Otherwise, the flame will continue to “burn back” into the mixing tube (until the gas pressure is finally increased), rapidly overheating the burner. In case of overheating, you must shut the burner down and allow it to cool sufficiently, before reigniting it. Once the flame retention nozzle is heated enough for its stainless steel to start turning colors (like a chrome exhaust pipe), open the gas valve up as high as desired. It will take very little practice to know how much to open the gas valve for a flawless burner start up, in the open air. Starting the burner within equipment is usually no bother. You Want to see a light blue flame, with a single wave front, no white inner flame behind the wave front, and little to no outer flame envelope (secondary flame) beyond the primary wave front. The outer edge of the flame is called its “envelope”; its forward edge is also known as the wave front. Why would the whole outer edge of the flame be called an envelope? Because gas flames burn from their outer edges, inward. When the flame retention nozzle has too much overhang, the flame will soften; a secondary flame will form and grow. Shorten the amount of overhang until the secondary flame disappears; at this point your burner has a neutral flame. Now, shorten the overhang more, and watch the flame color turn darker blue; it has left the neutral flame and is becoming ever leaner (oxidizing); with some burners, the flame will snuff out almost immediately, instead. Other burners can create a highly oxidizing flame before it is snuffed. Lengthen the overhang again until the secondary flame starts to appear, and adjust the nozzle back to just where the secondary flame nearly vanishes; that is where you want to keep the overhang; lightly tighten screws. When the nozzle starts turning incandescent, lightly tighten the screws again. If the flame is leaning off center, shut the burner down, and let it cool off. First, check to see if the gas orifice is axially true to the gas tube; if the problem is in the MIG contact tip, this soft copper part can simply be bent into alignment. If the orifice is a brass 3D printer nozzle, unscrew it, and sand the end of the gas tube to square its face up with the gas tube. If the gas tube turns out is out of alignment, hook up the burner up to a water hose, and turn on the faucet, to see exactly where the stream is canted. Loosen the screws on the gas assembly’s mounting plate, one at a time and place a bit of tape, etc. between the mounting plate and funnel’s flange to see where and how thick a flat washer needs to be inserted to align the flow of the gas jet. Use the square or calibers to make sure the tube is centered. Use the square’s blade, to compare it with the mixing tube, to ascertain that the flame retention nozzle is centered and in axial alignment the burner's mixing tube. Use your digital caliper to measure all the way around the rear edge of the flame retention nozzle, to assure that it is centered on the burner’s mixing tube; then just snug the rear set screws in that position. Next, use its straight edge, all around the nozzle to check that it is parallel to the mixing tube; adjust the three forward set screws, until it is, and then tighten them again. Now, tighten the rear set screws. This method allows you to ensure that the nozzle is positioned parallel and centered on the mixing tube, without changing the amount of its overhang. Ignite the burner and visually check its flame, to assure that it is running true; not canted. When the nozzle is incandescent, tighten all six set screws, again The end of your gas orifice should be “in the ball part” for position, somewhere between 3/8” ¼” away from the mixing tube’s opening, but each burner’s gas assembly has a slightly different sweet spot. Move the gas assembly’s tip back and forth to find it. At the best spot, your burner should roar the loudest. In any case, do not let the tip get closer than 1/4” to the mixing tube opening, or further away than 3/8”. If you think your burner runs better at some other distance—you are simply kidding yourself. So, if you do not see any difference in the look of the flame, but only in its sound, what difference does this task make in burner performance? When you hit the sweet spot, your burner’s gas jet draws in (induces) the maximum amount of air, at every gas pressure level. So, you will always be able produce the best performance with the end of its gas orifice positioned at the sweet spot. Do not be surprised or concerned by thin yellow, orange, or red streaks in the flame, which can develop after the nozzle heats up sufficiently, or immediately, if you did not clean all debris from within the burner’s gas assembly; they are caused by a reaction between the superheated oxygen and the and the stainless-steel of the flame retention nozzle (much more prominently from #304 stainless alloy than from #316), and by any other burning metal debris. Streaks from copper or brass debris, will burn green. Heated gas rises, and so, the burner’s exhaust will enter your burner’s air intake if the burner is held near enough to the vertical down facing position, destabilizing the flame (this is unlikely to happen, unless the burner is connected to hose; otherwise, a fuel canister will probably dump liquid fuel into the burner before you reach that point, causing even worse problems). Practice bringing the burner to this position and then backing it off, until you feel confident of your understanding.