Oh my; it's true. 020 MIG tips exist. I will have to buy some and test how much oversize they are, and whether the designation is for wire size or through hole size. Wire size would probably mean they are perfect for 1/2" burners. If they have a bore of 0.020" (.6mm) they are perfect for 3/8" burners 

The bore is supposed to be 0.023" which is just about perfect for 1/2" Mikey burners. I will need to build a new one with this tip after gardening season is over.
 

I started taking my feeler gauges to determine the actual ID of mig tips, they are all 3-5 though larger than what's marked. Of course that's because the label indicates the welding wire size, not the actual contact tip ID. The 0.035" contact tips I use for jets actually measure 0.040" +/- .001. I spent a lot less time tuning my burners when I started gauging the mig tip IDs.

Mike the ID of 3/4" plumbing pipe sometime. 3/4", . . .  round? SNORT!

Frosty The Lucky.

23 hours ago, Frosty said:

Mike the ID of 3/4" plumbing pipe sometime. 3/4", . . .  round? SNORT!

Started out building burners with black water pipe, and gave up, after the book was published. Stainless steel pipe is just way better. Clear back then, what convinced me wasn't its dimensional shortfalls, or out of round condition, but the internal weld seams on various different pipes being utterly unpredictable; some of them had smooth beads about 3/32" high and others were an irregular lumpy mess about 3/16" high. How is a fella supposed to get predictable results that way?!?

How to get predictable results using unpredictable components? Pretty easy actually, don't try for max performance so you have a cushion. 

The T burner is significantly detuned from the performance I could get with some tweaking, let alone going for max performance from the drawing board.

That's where Ron Reil, you and I differed from the beginning. Ron was a science teacher and strove to get a near perfect fuel air mix but used a linear so was required to use a smaller jet and higher velocity. You improved the design strategy but were still limited by the physics of the design.

My goal wasn't for max performance, I aimed for effective and easy to build with basic tools and shop skills. I settled on a jet ejector because they LIVE to induce air, water, smoke, sawdust, beans, etc. To induce a flammable volume of air a T burner is operating at the low end of the performance curve. I only drilled the jet on the first couple three experimental burners. 

The first successful burner was 8" of 1" dia. pipe with a 1" x 1" T, lamp rod and a brass cap with a drilled jet. The forge was a cylinder of about 750cu/in with 1" of 8lb. Kaowool and IIRC a 3/4" thick rammed hard refractory flame face. 

Had a get together of local farriers to show them what I built and talk about it a little. Stuck a length of 1/2" sq in the fire while we talked and in just a couple minutes one of the guys pulled his out and the end 2" of hissing sparkler bar slumped and fell off.

"Nope, that won't weld." 

The point is that burner was so grossly over powered for it's size it wasn't really usable. Maybe in a melter but not a forge. When I start experimenting with something I don't know much about I reach for the low hanging fruit. Define the extreme ends of the curve and split the curve and repeat. 

If I make a 4th prototype it's because I'm messing around with a new idea.

Frosty The Lucky.

 

17 hours ago, Frosty said:

How to get predictable results using unpredictable components? Pretty easy actually, don't try for max performance so you have a cushion. 

Where's the fun in that? Seriously, I said from the beginning that the more good burner deigns the merrier. All this stuff is just a hobby for me. At present the flower gardens are more important. Come winter I will play in the garage, to avoid all that nasty rain 

Oh I know, you and I didn't start talking directly until Iforge IIRC. Heck Ron and I were subbed to theforge.list and I'd already been using a T burner when I discovered there were blacksmiths online and joined. Anyway, Ron and I talked burners briefly and our differences sort of cut communications short. 

He really didn't like it that I'd tried and given up on linear inducer type burners for jet ejectors before we met. I couldn't get a linear to work well without all sorts of tinkering during the build and when I realized using mig tips instead of drilling hole after hole till I got the right size jet was WAY faster and easier. Mig tips didn't solve all the structure necessary to hold a choke disk and the jet fittings. One of my coffee shop buddies, (counter culture) name of Cruz gave me a bundle of papers, articles, etc. about Jet ejectors. HOLY MOLY!! In the "real" world jet ejectors are used to draw vacuum as in a vacuum cleaner or draw large spaces to hard vacuum. The Aims Research vacuum test facilities where spacecraft like the Shuttles were tested in hard vacuum are all drawn down with jet ejectors. Sure they're the size of a RR locomotive but the principle is the same.

My first attempt was what is now called the "side arm" but drilling and tapping a T more than doubled the intake port diameter meaning 4x the area so I could mount a jet 2x the dia. and quadruple the fuel air mix I could put in the forge per second. I discovered that doubling the jet dia. only quadrupled the flow IF I cut the psi in half. So instead of putting 18psi to a jet for X CFM output I got the same volume at 9psi but at half the velocity. 

And through a jet ejector induction follows a pretty flat curve so cutting prop psi in half cut induced combustion air in half.

That was that, that was the T burner. Build is simple and easy though you MUST be reasonably precise, tune it once and it'd done. Put it in the forge and it runs with a SLIGHTLY reducing flame (my preference) no matter what the regulator says within a pretty wide working range. Sure, below 7psi and it sputters and or burns back, over 25psi and it starts to burn lean (oxidizing) and off the flare.

Heck, I didn't even know the thread protector I dipped in Kaolin clay slip was a flare. I put them on as a sacrificial nozzle so I wasn't always replacing mixing tubes. From my perspective the #1 reason to put a flare on a NA burner is to increase air induction by lowering the pressure in the mixing tube which allows you to increase propane volume at a lower psi. Calling flares a flame holder is common. You and I have talked about this before. Holding the flame is secondary to improving the the volume of fuel air introduced into the furnace chamber at a lower velocity. Holding the flame is more of an indication that the flare is working properly than it's purpose. 

Of course that's just my opinion, I could be wrong.

Sorry, off on the old memories sidetrack. Anyway, almost everything about a jet ejector intended to induce JUST enough air to make a proper flame is a significant detuning of what jet ejectors are really intended for.  I don't worry about the weld seam in the pipe, if anything it increases turbulence slightly improving mixing. I don't even debur the tube. I was shocked when I machined the threads out of the intake ports and thread protector "flare" and discovered it reduced the burner's effectiveness. I even tried machining a straight coupler into a 1:12 flare and it was less effective than a threaded thread protector.

Sooo, I did some reading about fluidics and Mr. Bernoulli's papers, No, the Bernoulli principle was not his discovery or work, he made it the center of his doctoral dissertation and got the credit. Anyway, what I discovered is air will flow more smoothly, faster and at lower pressure over a series of ripples than along a smooth surface even if it IS curved. The dog gone'd internal threads provide a far more efficient flow than smooth pipe. 

DANG it's a good thing I gotta go to the bathroom, maybe I'll unstick my brain from this rabbit hole. But YES I did a lot of thinking and research to develop the T burner, just to different ends.

Frosty The Lucky.

The only thing wrong with what I read here is that it belongs in your "T" burner thread, lest future researchers miss reading it. I started the two 101 threads to encourage readers to mess around and come up with newer burner and forge designs, that I can't even imagine. The more information we leave behind the faster they will come up with new and better ideas.

On the other hand, it is fun for me to hear the history of your technical journey.

I went straight to employing MIG contact tips in burners simply because I had been using them for MIG welding since the sixties. It seemed smart to suggest them as the easiest means for people to buy and mount superior gas orifices in their burners, which they could buy at their local welding supplies store. These days, it is even easier to buy them online.

However, I had been falling behind, having no idea that 0.020" welding wire even existed. This was a serious boo-boo, because their 020 contact tips for 15AK MIG guns use M6 x 1 threads; the same threads as 3D printer nozzles, making 1/2" size burners (how very convenient for experimenters) 

You're right Mike, I got carried away talking about a surprising success. I've been having headache after headache with MS Edge as an operating system and must've needed a bit of a happy story for a change.

Sorry everybody I didn't mean to detract from the subject. My bad.

Frosty The Lucky.

Frosty,

I'm not saying that you're off topic. I'm asking you to post a copy of what you wrote were it won't be drifting out of notice. I'm saying that it is worth keeping some place where it will still be viewed next year and next decade.

Yeah but I've written the story and much better I don't know how many times on the forum. Writing up another and posting it where it'll probably never be read isn't much of a priority anymore. Take a look at how many newcomers ask the open forum questions  that have been answered hundreds of times. Young people now days are used to instant access to what they want to know, unlike you and I who had to learn to do actual research. Most folks won't even look at the table of contents let alone look at section, subject, topic, titles, etc. 

If I wanted to start another topic, section, etc. I'd cut and paste one from an earlier T burner post. 

The point I wanted to make was the relation to mixing tube and flare sizes. This too is all in the basic gas burner threads. Any NA gas burner is almost infinitely scalable, it is the ratios that count, not the details. 

The exact same principles were used to ventilate mines as far back as ancient China, as far as documentation goes, undoubtedly earlier.

I'm just more tolerant than Ron is / was but his complaint and outright anger is due to the exact same reason. (note, no adjective) People would ask him the same things they ask you or I here without bothering to read a word. AND as you've seen repeatedly here the un-motivated individuals actually got mad and abusive if he sent a link and told them to read the article. Hmmm?

Seriously, just in the last couple weeks I've been called rude for saying the same basic thing though not in proper soft, nuturing terms. Feelings have no part in the blacksmith's craft and I won't encourage dangerous misconceptions. The steel, tools, equipment, heck physics necessary to hand forge steel are HOT, HARD, HEAVY, SHARP AND ALWAYS READY TO BURN, BRUISE, CRUSH, SLICE, GOUGE, SLASH THE SMITH.

Just entering a shop is inherently dangerous, let alone picking something up or heaven forbid turning something on. Metal work is NOT a safe craft and I instruct in plain direct English. 

I'm not singling out the OP of this post, I should've replied less angrily that is MY bad and acknowledge it. I've apologized and am ready to help as much as reasonably possible. Just like I have for the past 15-16+ years on IFI.

The toughest part of these kinds of projects is convincing the beginner that what they've watched online, read in blogs, imagined themselves, etc. has to be discarded if they wish to be successful or more importantly as safe as this craft allows.

Off on a ramble again but there it is.

Frosty The Lucky.

 

Oh, how fortunate that I never wrote for the people who have you so aggravated; never even imagined getting through to them. They have no more existence than strangers in a crowded street, as I walk by.

From the beginning I wrote for the less than one percent, who listen and learn...at times.

When I answer individual questions, the same attitude applies. So long as the person makes the slightest attempt to understand, I do not mind repeating, repeating, repeating. Sooner or later, they get it, or they give up and just go away. Since my aspirations were low to begin with, its all fine.

Knowing that I too am a blockhead, has a few advantages 

Wish I'd learned that earlier but arguing my case was ingrained into me since I was little. It's tough to kick old habits, heck it was a card table sport when I was a kid, along with round robin pun contests, cards, Yatzee, etc. It'd start as dinner was winding down and usually continued for an hour or so afterwards. Unless Bonanza was on, then we all watched TV. Dad had his favorites you know. 

I am getting better about not engaging knuckleheads or trouble makers though I slip now and then. Sometimes they even turn into cyber stalkers. The cholla cactus of the internet. They might look cool but do NOT touch or even get close!

Frosty The Lucky.

Quick update. First they are .023 tips. Sorry my 40 something year old eyes couldn't read haha. Second, I just finished building the first burner following the book steps exactly. I will make a second but wanted to make sure I got one done and it worked before making two and messing them both up. Good god these work a whole lot better without the changes the other plans I followed made. I went with three port holes instead of 4 and used schedule brass pipe for the accelerator tube. The tips I had were actually 1/4-20 thread at .030. Just got it fired up. Much better flame than the first ones I made and outside the forge ran really well at 5 psi. Now I'll make my second one and get them installed.

As satisfying as that is to you, you have no idea how satisfying it is to us to have someone listen to the advice given and experience the success that follows.  Thanks for the update.

Ditto Buzz.

Frosty The Lucky.

Kintan,

You wrote "I went with three port holes instead of 4 and used schedule brass pipe for the accelerator tube. The tips I had were actually 1/4-20 thread at .030. Just got it fired up. Much better flame than the first ones I made and outside the forge ran really well at 5 psi."

Three air intakes instead of four proves that you are paying attention to our advice, because that change was post publication.

Using schedule #80 pipe was another guy's excellent idea about two years after the book came out. I went with schedule #40 pipe to make it easy for people to buy, giving up too much in return for too little 

You will probably find that 5 PSI is the bottom of a 3/4" Mikey burner's turn-down range; all of mine started huffing at 4 PSI.

1/2-20 thread is a little unusual, but not a problem. However a 0.030" diameter through hole on a 023 MIG is excellent! I started out with Tweco tips back in 1999; back then they were the best tips available, and their through holes were 0.031". Then imported tips flooded the market, and pretty soon 0.035" was standard. So, your 0.030" tips are a very good find 

It would be good to find out how far you can turn down you improved burner. I would love to know.
 

Gentlemen, I'm glad I made you happy by listening to your advice haha. "A smart man figures it out, a genius listens to advice from others that are smarter than him."

I'll admit a big reason I rebuilt the entire burner is because it's not crazy expensive. And I had all the brass tubing and nipples I needed besides the schedule 80 so I didn't have to drop a ton of cash to redo them. I also figured these would be better and save money in the long run.  In the beginning, I thought the design I used was a good design. It turns out it wasn't, and when the guy who designed the dang thing tells you it's a bad design....it's a bad design haha.

Ill get these fired up and let you know how low I can take the PSI.

Thank you; I am looking forward to that, because it will show how much a slightly smaller gas orifice can improve performance. I am always interested in every little improvement.

"A smart man figures it out, a genius listens to advice from others that are smarter than him." Good one, Kintan. I will be sure to steal that saying 

37 minutes ago, Kintan said:

when the guy who designed the dang thing tells you it's a bad design....it's a bad design haha.

I would rather congratulate people who change my design successfully. Two different guys changed the design to improve their ease in building commercial versions of the burner, with great success; all it takes is understanding the why behind its construction details. Then, you can mess and change to your heart's content. After all, that's what the designer did 

I was able to get them running smoothly down to about 3 PSI. I'm wondering if this is too much dragons breath outside the forge. The flames look really yellow on camera but look much less yellow in person. The exhaust is a 4.5" circle out of the back.

Yellow flames are far less of a concern than a combination of purple, yellow, and worst of all blue flames coming from your exhaust, because yellow flames may only be caused by binders outgassing from the forge lining; if they are burner flames, you just need to back off the fuel pressure to give those flames room to complete combustion. Blue exhaust flames are always, burning carbon monoxide, which is always the byproduct of incomplete secondary flame combustion in the forge chamber. Turning the fuel pressure down will have little effect on them.

Getting back to multiple colored exhaust flames; these are what we call the tertiary flame envelope.

The best possible air-fuel flame is a single blue flame envelope; this also known as the flame front. Why flame front? well that goes back to velocity testing for different fuels. However it is a another legitimate term for the flame envelope, because gas flames burn from their exteriors inward. So, although the two terms are very different, they are describing two aspects of the same phenomenon.

Imperfect gas flames have a primary, and a secondary flame envelope; these are typical of reducing flames. This isn't necessarily a bad thing, so long as the secondary flame envelope combusts all of the fuel, which escaped the primary flame envelope. The burner on a gas stove has this same kind of flame. So do most lab burners, and even oxy-fuel torches. So-if all the fuel gets burned within a forge, so far so good. Here's the rub. Secondary flame get longer as they become more reducing. Blacksmiths know that a little secondary flame is good, but more sure ain't better!!!

Now we come to the dread tertiary flames. What are these multiple colored monstrosities all about? They are the product of out of control flame speed. Your burner's gas orifice is designed to enhance speed of the gas jet; this induces air into the burner. However, too much a a good thing, becomes a very bad thing. An undersized gas orifice, or over pressurizing the fuel flow into the gas orifice will cause some of the gas molecules to outrace the induced air molecules needed for combustion. So, we end up with several different stages of combustion going on in the forge. Just as a highly reducing flame becomes way to long to be completely burned within the forge. Tertiary flame takes this problem into overdrive. 

Whatever shall we do?!? Begin by simply backing off the gas pressure. Once you have control of the situation, experiment with your burner to learn its limitations, and peculiarities. To successfully turn the gas pressure up higher, you may need a larger gas orifice. I don't mean using a larger MIG tip, I am talking about a couple thousandths of an inch. And I am repeating that you need to become much more familiar with your burner, out in the open air, before you change anything on it. I will need photos of its flames, out in the open air, to zero in on just what is going on with it.

    The people who have the worst problems with their burners, and therefore their forges, usually end up with the best burners, once they learn to control them. How can that be? Burners are kinda like race horses; the spirited ones are cantankerous; they still beat a worn out old plug all hollow

 

If anybody out there cares you can read the bunches of threads and polite arguments Mike and I had about burners. We just made two very different types and when we hashed things out discovered the rules were the same it was just the application in two very different induction engines. (burners)

I have nothing to add to Mike's remarks above he's way batter at this sort of thing that I.

Well . . . Unless he gets it wrong. 

Frosty The Lucky.

On 8/11/2025 at 1:11 PM, Frosty said:

Well . . . Unless he gets it wrong. 

Frosty The Lucky.

Fifty years back, I would have worried over that. These days, it's just an opportunity to learn something new. Old dogs don't care who is winning on any given day, cause the races go on and on down at the track, and the 'bunny' is fake.

Ayup, I'd rather know I was wrong than think I'm right.

Frosty The Lucky.