Burners 101

[Mikey98118]

    If you use a silver braze alloy with as high a melting range as you can find, along with black flux (which is rated for stainless-steel), this will provide a high temperature bond that requires less care to keep a rivet nut in place, while brazing the ends of the mounting plate’s three ribs onto a funnel, with easy flow silver brazing wire and a lower temperature rated flux. Water-soaked rags, or blocking putty (ex. Wetrag) around the nut, but kept away from the second area being joined, is another way to help protect existing silver brazed joints. Anti-flux can be placed around a joined area that is too close to the new joint for blocking putty to be used effectively; by resisting fluid flow out of the area of an existing joint, it will help you to protect it, while brazing the second joint, if you waste no time. Lamp rod couplings, or re-threaded 1/8" x 1/8" brass pipe couplings can be silver brazed onto steel mounting plates, but their lack of an external lip will reduce the joint’s contact area too much for silver soldering to create a strong connection.

[Jimw3326]

On 9/7/2023 at 7:52 AM, Another FrankenBurner said:

I purchased a product called Tap Magic many years ago. It worked so well that I eventually bought a gallon. I use it for drilling and tapping.

Still, the second you feel resistance, reverse, then forward.  Peck all the way through.  I have gone against the wisdom of Frosty’s last post and broken taps.  It has been a long time since I have broken a tap because I never try to get just a little more when the tap starts to bind.  When the part matters, a piece of broken tap stuck in there is always an adventure.

Also, drill the correct size hole for the tap. Depending on how much thread engagement you need, you can get away with a little too big but a little too small is no good. 

I've been using the Tapmatic Edge lube for all my machining and such. It makes my carbide bits last about 4 times longer than any oil except a flood system. Since I don't have an enclosed machine, the wax is perfect. Tapping is a breeze, drilling is smooth and leaves a better finish inside.

[Mikey98118]

So, twenty-three years into burner construction, I have come to some tentative conclusions on homemade burners:

Shop-built linear burners of the eighties (and earlier) simply were not well thought out by people who were anxious to find something to heat the forges they wanted to market. It seems likely that they just viewed the flames from the commercial venturi burners of the time as “top of the line,” and then produced what they considered as “good enough.” If our expectations are too limited to begin with, our idea of “good enough” is likely to be pathetic; sure enough, that is what gas forges were for quite a few years.

 

Jet-ejector style burners induced a lot more air than linear burners, so the switch to home-built jet-ejectors brought instant relief from the problem of weak linear performance. However, the problem was never burner type, but very poor construction choices, due to low expectations.

 

Unfortunately, we “tossed out the baby with the bath water.” Linear burners still have the greatest potential for gas/air mixture flow manipulation; that is the foundation of superb flame management, which in term is the only path to greater heat for less cash.

In summary, a good output begins with a well-controlled input.

 

Where might the future path of home-built burners lie? Back again to classic wasp-waist venturi burners, but with a couple of twists: First, such a new generation of linear burners must keep a stricter idea of what constitutes an acceptable flame; that only begins with complete combustion in single flame envelopes.

  Finally, the perfect must bow to the practical. What is practical in home-built burners is primarily limited to method (ex. tooling); not by building effort. I predict that the next big improvement well be completely ceramic wasp-waist burner bodies, with refractory flame retention nozzles.

Thoughts?

[Frosty]

I think t hat's pretty accurate Mike, close enough I can comfortably keep my mouth shut. 

Yeah, RIGHT. Why differentiate between a ceramic burner and refractory nozzle? Since the prices came down why not make the entire burner from a high zirconia refractory like ITC-100?

I'm thinking a ceramic refractory cyclonic Frankenburner would be a nice one to see developed. Hmmm? 

Frosty The Lucky.

[Another FrankenBurner]

That would be a thing. Sounds tricky to produce. 

[Frosty]

I'd have to take it to a high end ceramic's shop and have it developed or perhaps produced. 

Were I still playing with burners I'd like to take a shot as a forge that the entire roof was a multiple orifice burner. Or perhaps a vault with the orifice angled so it made a serious vortex.

I keep having these thoughts all the time. I hear T H O U G H T S! 

Frosty The Lucky.

[Mikey98118]

 

Back in 2002 I had a thought swirling around my noggin for a new burner design. For about six months, I would lay down and be very still until it departed. Then, I suddenly needed a new design, and had to give in to it. Out came tube burners, and the rest is ancient history. So, plunge in at the deep in, 'cause the water's fine

Ceramic versus refractory (as I see it): By definition, all ceramics are refractory. The distinction is in sales terms, only. Clay pots, etc. are considered as ceramic, becuase, while they are finished through high heat, they are no longer able to withstand that same heat; what is labeled "refractory" is.

So, a fired clay burner body would be considered ceramic; it can withstand slower and lower temperature increases, but is less costly and a better medium for slip casting than a typical cast refractory, which shall be needed for flame retention nozzles. Nevertheless the two materials should have similar enough ratios of expansion to avoid major joining headaches (if I'm right about all this).

And if I'm not? Then, grab the ball and run with it

[Mikey98118]

9 hours ago, Frosty said:

I'd like to take a shot at a forge that the entire roof was a multiple orifice burner.

Actually, that idea sounds like it has lots of potential.

[Frosty]

Maybe but I've been a little disappointed in the loss of general forge temperature supplied by ribbon burners. The trade off from temperature for even heat doesn't make me want to tinker with a multiple orifice wall forge, even if it's just the roof.

Heck I haven't even made a shop drawing for my last idea I thought was worth building. 

I've also been giving thought to the really old propane forges made by covering a ball with refractory. By "really old" I'm remembering it as maybe 30-40 years ago. In the day when everybody "knew" you couldn't weld in a forge with NA burners. I was spending a little time with a fellow who owned a commercially made NA propane forge. (No, don't ask the name, silly!) He was in the process of building a propane gun burner and offered me a "deal" on his old one, about new price less shipping to AK because it was well used.

The thing I didn't like about the spherical forge was the un-flat floor and everybody aimed the burner straight down from top center. My thought would be to lay a flat floor maybe 2/3 from the top center and two burners aimed tangentially on a down angle, one on each side. Basically super heat the semi-spherical roof with strong vortex flames that were directed downwards along the walls. 

Unless I was really mistaken the spherical flame face would act as a lens focusing the re-radiated IR towards a point just above the center of the floor.

It's just a mental thing, I can see it but it requires a couple things I THINK to be "right" to actually work and I just don't want to go to the hassle of making a couple prototypes to see. 

I have tried "casting" a shallow dome flame face forge roof and wasn't happy with the results at all. I don't use Mizzou though so I can't write it off as a failed idea.

Frosty The Lucky.

[Mikey98118]

I would think that one of the zirconia tile formulas might help, if backed up with a layer of insulating cast refractory. Of course, that is a far more costly commitment than I would want to invest in an experiment.

It is amusing to find our usual points of viewpoints reversed. You are looking for superb performance from radiant energy, while I stopped at just good enough

How did this happen? Because I only look at forges for general use these days. If you are focusing radiant output for a narrow use (items of a particular size range), well and good. But if I then want to stuff anything in there that is small enough to pass in and out, with the additional help of a latching door, that ruins the whole idea.

So, it turns out that your view is consistent. I must agree that the the least general equipment can be made to produce the best performance.

[Frosty]

Oh yeah, I'd about stopped making new burners and had a perfectly good enough forge when Kastolite 30 was brought to my attention when I was picking up some 8lb Kaowool for a club build project, I'd been building double lined forges since #1 was in the works. It seemed too logical not to after seeing a professional's forge smoking dust and smudges off the outside while in use. 

I changed up to kastolite, not looking for exceptional but because the uninsulated hard refractories were no longer "good enough," same as a single liner forge. They just don't cut it.

I don't see the semi-spherical, (bee hive?) shape is focusing the IR radiation in a tight area, it just might have that one thing that all gas forges lack, a hot spot, the rest of the chamber would be a pretty even temperature. I've never much liked the requirement of quenching work when I need to localize the heat. Usually a couple shades in color is all I need to oh say localize a twist transition and taking a water can to 8" tends to make it too cool for a smooth transition so you have to reheat it to even it out.

Sure you can dribble water or use a wetted rag (risking skalds if you're not careful enough) but the work is losing heat in general while you're dribbling on it. 

Would the bee hive do what I want? I dunno know and probably won't. It's just an idea of the many ideas that float through my head all the time. 

Heck, I can make localized heats and transition the temps and get it right in seconds with my torch. 

I don't spend time in the shop like I used to. I go out when I have to do something or like recently have a special project. The flower for Glenn's memorial project.

Brainstorming ideas though is always good times for me though.

Frosty The Lucky.

[Mikey98118]

3 hours ago, Frosty said:

I can make localized heats and transition the temps and get it right in seconds with my torch. 

That sounds like the practical solution.

[Mikey98118]

                                             Drilling and threading brass gas tubes

Most brass tubes and pipe fittings that you buy, and turn into burner parts, are half-hard brass; this can be drilled and threaded more easily than stainless-steel alloys; however, it can be tricky to tap threads into, or run a die down; it tends to gum up tool edges on dies and taps. Half-hard brass is inclined to compress during threading; this is a form of work hardening. Tapping fluid should be employed during threading; it can be purchased in amounts smaller than a pint). Even cooking oil is better than dry threading.

Internal thread: Always tap the internal thread for whatever part you employ as a gas orifice first. Run the external thread second.

    Tubing sizes may be a little small inside; in that case use the recommended drill size to enlarge it before running internal thread with a tap. If the tube is a few thousandths oversize, that is okay.

    Many novices lack a drill press, and see no use for one; they will be tempted to drill and thread by hand. However, a cheap drill press vice is only about ten dollars, and by placing your parts in the vice before you try hand drilling or threading, you will stay parallel with the tube or fitting's hole, far more easily (keeping tube in the vice will also help you to correctly start a die down its exterior).

    Start threading with your tap as axially true as possible, and only turn the tap until you can feel resistance suddenly increase (the “quarter- turn and reverse tool to break burr” rule of thumb is not adequate for half-hard brass; instead, you must back off the tap as soon as you feel a sudden increase in resistance to movement. It does not matter how little progress you make before breaking the burr away from the thread end, and starting another twist; have the patience to follow this advice. You are going to be using small (and therefore easily broken) taps in ¼” and in six-millimeter gas tubes. Also back off the tap every full turn forward, and run it back over the thread you just made to clear burrs, and smooth up the new thread; otherwise, after a few extra twists, so much pressure might be needed to do this, that small taps will break off in the hole, as you attempt to back them out. Be liberal with your tapping oil. Dealing with a broken tap is no fun. Should you break a tap off in the tube, gently beat back and forth on its protruding point, to loosen it; then, try to back it out of the hole with pliers; if that does not work, cut away that section of tube, and try again with a new tap. You should have no need to use a drill bit in 4mm inside diameter tubing, and even a plug tap will suffice for the purpose, unless your tubing isn’t actually 4mm inside diameter for smaller gas tubes, or 3/16” inside diameter on larger gas tubes; that is not very likely, but these are imported parts; which means you are probably going to be dealing with an ignorant drop- ship seller (meaning they “don’t know and don’t care” about actual sizes).  

External thread: If the tube is a few thousandths small on the outside, that is okay. If the tube is the slightest amount oversize, your die will have far more work to do; spin the tube in a drill motor, and sand that extra diameter down to size; especially when running coarse thread, like 5/16-18. The coarser the thread the harder it is to run. But the coarser the thread the less of it that needs to make contact. 75 percent contact may be needed in a fine thread, while fifty percent may work just as well in a coarse thread. Even the same outside diameter as the die can be hard to work with. If the first half-inch of thread is a slog, consider deliberately sanding the rest of the tube’s length a few thousandths of an inch undersized. Full contact in the first half-inch (at the tube’s end) helps to secure a gas tight joint, but it is not needed, or even desirable on the rest of the gas tube. So why work  hard?

    Use the same care when threading with dies as with taps. Dies usually have their description written on the opposite side that is meant to face the work. Be careful to mount the die facing correctly, and grind a bevel on the tube’s end, so that it will get started correctly; this helps the die to start threading at true right angles; if you start the die threading close enough to perpendicular to the tube, it will finish truing itself up, within a twist or two.

[Mikey98118]

                            POPULO 8V Rechargeable Cordless Rotary Tool

The price was low, but everything about the order packaging, and deliver time, was first class. I found this product to have surprisingly high quality, for what it is; it has as much power as the average 160-watt 120volt rotary tool. How well the controls will hold up over time, is still an open question; it has a 2.0Ah battery, four LED Lights, and five speed adjustments. The 124-piece accessories kit is fair quality. This tool comes in its own plastic case. For a battery powered rotary tool, it is a pleasant surprise; $29.80 through Amazon.com.

[Mikey98118]

                                                            Brush-less DC motors at a glance

How can we know that a tool has a brush-less direct current (BLDC) motor? Looking for evidence of brushes on the motor housing is fine and dandy, if the motor uses a tool's body as its housing; more often than not these days, a separate motor is simply placed, housing and all, within a larger tool body. So much for looking for brush covers.

If you twirl the motor's shaft (or whatever spindle it is connected with) in your fingers, there well either be a smooth minor resistance, or a considerable pulsed resistance. The smooth resistance comes from a brushed DC motor. The pulsed resistance is from a BLDC motor. Why? The BLDC motor has permanent magnets built in. A brushed motor uses more than forty percent of its current to run electromagnets, which offer no resistance before current is applied.

This is the reason that the higher quality battery operated equipment is all switching over to BLDC motors, and why, at present, a twist of your fingers is the surest test of quality in cordless tools.

The POPULO 8V rotary tool has a BLDC motor, although that fact is not mentioned in their ads

[Mikey98118]

 

 

Choosing Power Tools

 

Rotary tools can replace a variety of other equipment for small-scale tasks; cost once restricted their use to professionals, but their expense has been declining for over two decades, along with that of their accessories. During that period, equipment choices have flourished, while steel cutting accessories and techniques have been improved; providing wonderful control for building a burner, and the equipment it heats. Rotary tools can easily have attachments added (ex. clear safety guards) to enhance their effectiveness.

    Electric die grinders have been getting more compact over the same period, and have now become attractive to home hobbyists, and tradesmen. There are 3” 12V angle grinders available, along with 6” chop saws, and conversion chucks that allow 4-1/2” angle grinders to spin 1/8" and 1/4” accessories.

    Now for the bad news; it’s the wild west out there. Nearly all of this equipment is imported from countries like China, and India; but prices don’t necessarily reflect their low manufacturing costs; while they are generally reasonable, you will find some marketers asking much more than the rest of the pack; showing the seller’s contempt for your intelligence.

    A favorite “bait and switch” tactic is a seller with the lowest initial price, followed with ridiculous ‘shipping fees’; there was even a version of this scam where all of the prices, including shipping fees more than doubled, while buyers were in the process of ordering their ‘bargain’ tool. Everyone who didn't pay attention got stung.

    Most people just get bilked with shoddy goods and service. There is a whole ‘industry’ that has grown up around drop shipping third rate junk. Before purchasing online, look at customer evaluations of the item, and the seller, on Amazon.com; not on a net ad. Grifters are trying every trick they can think of to get around this system.

    Where do you think look- alike super cheap tools come from? Foreign factories have quality control too, but their rejected parts are more likely to be discounted, than scrapped.

    American’s have long trusted brand names that mostly mean zip now. Some venerable companies are having their power tools built in China, and then charging the highest prices you’ll see; prices that couldn’t be justified even if they had been “made in America.” Before paying an outrageous amount, in hope of buying quality, thoroughly read through critical customer reviews of that name brand product; they are more likely than not to provide some chilling surprises. There are still quality tools built, but they are more likely to be Japanese or German brands, than American. You don’t like this? Neither do I; which changes nothing.

    BUT, consider whether or not most of those bad reviews are legitimate, or just showing the complainer’s ignorance. Most of the larger mandrels I recommend for this work, are frequently dinged as “poor quality” buy users who fail to insert the mandrel’s shank completely into the tool’s spindle; you can tell this, because their “outraged photos” show mandrels bent somewhere toward the middle of their shanks, rather than just below their heads; demonstrating what they did wrong, and that they still haven’t bothered to read a rotary tool instruction manual. Repeat complaints fall into two categories: real problems, and user ignorance. How do you tell them apart, if that the tool is new to you? Look up a similar product that is known for its high quality, and read the complaints listed about it. The remarks that match, can reasonably be put down as user ignorance; the ones that do not should be taken seriously. If you see owner after owner complaining that a tool just fell apart and/or quit working “right out of the box,” it would be silly to assume that all those people were just too ignorant to use the tool properly.

    Between fly by night drop shippers and recognized tool lines, are importers who have developed their own product lines over several years; what difference is there between them and the majority of yesterday’s brand name tools? Not much, since both types of company are essentially just sales outfits these days, with fairly weak motivations for ensuring customer satisfaction; they are better than anonymous drop shippers, but that is a pretty low bar.

    However, the one who needs watching most, is you. Tools “are what they are”; not what you wish they were, or what you think they should be. When you go shopping, leave all your hopes and dreams behind. Go beyond practical, to outright cold-blooded.

    When it comes to buying power tools, remember that old street adage; “nothin’s fer nothin.” You will find a frequent refrain in bad product reviews; “you get what you pay for.” Not necessarily, but you can be sure you are not going to get more than you pay for! There is no simple formula for ending up with a good tool. Either you will do some research before buying, or just roll the dice and hope. “Made in America” is the past. Your new standard should be “made with reasonable care, and backed by something more than happy talk.”

    Skip right past all those joyful five-star reviews, which mostly boil down to “A sparkly! I’ve always wanted a sparkly of my very own.” Go straight to the one- and two-star sections; both of them will bring up the same problems, but the two-star section tends to have more clear minded comments, while the one-star section has more rage. Consider what percentage they amount to, together. Finally, look at the three-star section to see how many of those reviews belong in the two-star section. 

    Are those reviews way out of date, or are there plenty of recent reviews that say the same thing? Some products do get improved; rarely, but it does happen. On the other hand, some sellers have begun blocking you from reading critical reviews. When you see that, just move on, because anything more that you learn, is only going to be bad news.

    When you see complaints about obviously used tools sold as new, it indicates that the seller is willing to fob off lemons on people, rather than accepting responsibility for them. If you buy into his jolly advertisements, instead of the bad reviews, you’ll richly deserve all you’re going to get.

    When you see rotary tools sold with their own case, filled with accessories, and a flexible drive thrown in, you are supposed to jump at the chance of something extra for free. What you will get is a pile of junk for more than a high-quality tool would have cost. Wishful thinking is willful stupidity.

    Another indication that the tool is junk-for-sale is awkward brush cap protrusions and/or no care taken to position air entrances were your hands won’t smother air flow through them. Plenty of junk tools do not have these flaws. But no care taken about such obvious defects, should alert you that more important matters, will not be seen to either.

[Mikey98118]

On 9/15/2023 at 9:16 AM, Frosty said:

Maybe but I've been a little disappointed in the loss of general forge temperature supplied by ribbon burners. The trade off from temperature for even heat doesn't make me want to tinker with a multiple orifice wall forge, even if it's just the roof.

Frosty,

This is a little bit late, and not the kind of viewpoint you would expect from me, but I have a question. Does the reduction in temperature indicate incomplete combustion, or just a slowdown in combustion rate? It would seem that the ribbon burners heat forges plenty hot enough to weld with, so the only practical difference would seem to be the rate at which work can be done? That would be important in a production shop, but with hobby equipment?

[Frosty]

I think combustion is as complete, maybe a little better with the slower flame velocity. NARB forge welds though it takes a little longer not having a hot spot. I'm pretty sure a production shop would use a Natural gas gun burner rather than NA propane. 

A hobby shop is a good spot for a multiple outlet forge, ribbon or otherwise, more so for a knife shop.

The fellow demonstrating at the club meeting this weekend was using his Mr. Volcano and has been happy with it for 3 years now. 

Frosty The Lucky.

[Mikey98118]

You have mentioned your preference for a hot spot in the forge, several times now. I have personally seen only one good example of this in a forge; it was a three gallon cylinder forge, with a single top-dead center 1/2" Mikey burner, that I built for a buddy; he wanted it to build specially items from 1/4" square bar.

The flame hit the center of its high alumina kiln shelf floor, and was forced to swirl around in two clockwise and counter clockwise directions. This scheme worked surprisingly well.

I expect it would work even better with a "T" burner...

[Mikey98118]

Of course, that was constructed several years before making my first 3/8" burner. If I were to build such a forge size again, it would have two 3/8" burners, so that one of them could be shut down to save fuel. Mikey is so cheap 

[Frosty]

I can hardly imagine a T burner working better than a Porter. 

The hot spot, should be more properly called the hotter/est zone is directly under the burner when mounted vertically and centered, the flames deflect off the floor in 360* about half towards the end openings the other half swirls in opposing directions around the chamber. Given time the temp inside of the forge evens out but the area under the burner remains the hottest.

When I aim the flame at an angle across the floor or towards the roof the forge has a strong swirl and the forge temp evens out more quickly.  Mounted tangentially It heats a yellow streak over the top or across the floor.

Frosty The Lucky.

[Mikey98118]

46 minutes ago, Frosty said:

can hardly imagine a T burner working better than a Porter. 

"No one shoe fits all." Furthermore, "enerh good burner does fine"

I just don't care he has the hottest burner; that isn't necessarily the best choice at any given time. I have admired you burner's combination of high heat and a softer flame, for years. Another Frankenburner's  3D printed burners are even hotter then mine, and multiple flame ceramic nozzles have their own considerable charms. Variety is the spice of life

 

That should read "every good burner does fine." I just ruined my own punch line...argh!

[Mikey98118]

1/4” and 5/16" bulkhead fittings are barbed hose fittings with a central threaded section that ends in a built-in hex nut on one end. A second nut pushes two washers against both sides of the bulkhead; they are meant to connect two sections of hose between a bulkhead (ship wall between compartments).

    You can cut away the barbed section beyond the hex, and tap the threaded section to match the exterior thread on your burner’s gas tube; this provides a generous length of threaded area, joining the gas tube and barbed hose fitting, which only needs to have the threaded joint sealed gas tight with glue. Afterward the threaded section can trap sheet metal fittings, being used as burner handles; these can then be mounted on your heating equipment, to secure burners in any desired position.

[Frosty]

Ahh, I get stuck on a thought and type. It's all about putting enough burning fuel / air in the forge per second to do the job. 

Not to blow my horn but I'm still amazed at how well the T burner works, #1 was just a wild guess and a little tweaking. Then it standardized to about what you see all over the place now. I'm talking 2 maybe 3 iterations and it was a clean easy to build burner. Heck a person can even turn one into a high speed burner if they want.

Things like that amaze me, it's not like I put a lot of time ad effort into them, I read a few things and made one. 

I just don't get it.

Frosty The Lucky.

[Mikey98118]

11 minutes ago, Frosty said:

Ahh, I get stuck on a thought and type. It's all about putting enough burning fuel / air in the forge per second to do the job. 

I spent nearly twenty years only concerned about how hot I could get a burner flame, without paying for added oxygen, or an expensive fuel like acetylene. Being single minded is good for getting things accomplished...until it isn't anymore.

I went with fast flame speed to get maximum flame heat. It was only after you guys got into ribbon burners that I slowed down enough to realize that the downside of fast flame speed is fast exhaust; that opened up a whole new train of thought about just what the point of a forge is

It is good to listen to the other guy...