Mikey style 3/4 inch burner built

[mariom2]

 

Hi Mikey and everyone at IFI,

I am new to blacksmithing and first time posting.  Would like to have a gas forge to start with and begin learning. I live in Ecuador and all refractory materials you use on the forges are difficult to get and will have to use what is available.

First thing I need is the burner, but with so much information on the internet, I did not know where to start so I bought your book from Amazon and decided to make one of your burners, trying to save time and guessing using your experience.

The burner is the ¾ inch and it was made as close as possible to the book measurements and description.

Once the burner was ready it was time to tune it and here I might need some help.

Here some pictures of the burner and the flame at 8 psi with a 0.035 mig tip. Accelerator tip ¼ inch from the fully open choke, choke fully open. Straight nozzle with 1 inch overhand.   

I would like your opinion.  Is the flame good enough or it could be improved?  These pictures are difficult to take.

Many experienced people here on IFI any comments are welcome.

Sorry if my English is a bit poor.

Mario

 

 

 

 

[Mikey98118]

The flame is not anywhere near good enough. Fortunately you only have a series of small changes needed to bring the flame up from unacceptable to perfect. If you will bear with us here at IFI, we can help you reach your goals, so let's begin with the needed burner changes before looking into what you can do about building your forge:

(1) The book's construction chapters start with a 1/2" burner size and then go on to the 3/4".  But the why of building design, and the how of tuning are laid down in that first burner's chapter it is easy to miss the information that keeps you on track, if you don't read that chapter.

The first thing that stands out in your photo is that you never got rid of the reducer's lip from its large end and than beveled that area to streamline incoming air; this results in major turbulence that cripples performance. Before you make this change, read the 1/2" burner chapter so that you can learn, through the flame changes it makes, how to start learning to correctly tune a burner.

(2) Your gas tube and MIG tip are not parallel to the axis of the mixing tube. Place a second line of three adjusting screws in the pipe reducer's small lip, so that you can adjust the gas tube into parallel with the center line of the burner. The harder the flame your burner makes the more important having everything dead center and parallel to the burner's axis will become. Having the MIG tip out of center and out of parallel this far would destabilize the flame if it wasn't so weak and slow as it is now.

(3) You have a short MIG tip, and that isn't good enough unless you have a schedule #80 1/8" gas pipe; the reason is that the thicker pipe has a smaller inside diameter ( of about 316"), which closely matches the opening of the MIG tip's threaded end. A more streamlined match of the two parts makes up for the shorter MIG tip. Do you have to use the thicker pipe? No; you can insert a sleeve of some other material inside the pipe to reduce its inside diameter.

BTW the tip size you choose is  too large. Even the next smaller tip of the chart on page 22 is marginal.

(4) The air opening in the photo looks good, but what have you got inside the pipe just beyond the MIG tip? That area should have nothing at all.

(5) The flame retention nozzle is supposed to be a stepped version. However you can do okay with the tapered nozzle you have, if you enlarge it a little more; give it about one more 1/8" in diameter.

Lest you think a heavy burden has been laid on you, the good news is that every step you take will improve your burner's performance. Start with step one, and quit anytime you feel satisfied

[Mikey98118]

Ho, Mario; are you still with us?

[mariom2]

Mikey,

Thank you for your reply.  No problem with the burden I think can handle it.

Before I proceed with the changes want to be sure I am getting your ideas clear.

Numerals 1-2 very clear.

3.) 1/8" pipe is hard to find around here, reason why I used 1/4".  I guess only have two alternatives: insert a 1/4" copper pipe sleeve inside to reduce the diameter and try to make a more streamline match or,  making the advanced accelerator from page 49.  Do you think it will work OK just inserting the sleeve?

Regarding the MIG tip  too large, it is a bit confusing.  The chart in page 22 calls for a .023" or .030" tip but in the list of materials asks for .030" -.035" and in the notes just .030" but you always mention a 1 1/2 inch tip, and in this case it is a short tip.  What size is you suggestion?.

4.) The area beyond the MIG tip is clear, it is just an illusion from  the picture, what you see is the other side of the pipe.

5.) Flame retention nozzle is not tapered.  It is a stepped version, inside diameter 1.260"

One extra question, a couple of times when firing the burner and warming it up, the flame got out on the outside up to the tip and really scared me.  It happened when I made some modifications with the nozzle overhand.  Any special reason for the burner to do this?

Mario

 

2 minutes ago, Mikey98118 said:

Ho, Mario; are you still with us?

Hi Mikey, yes I am.  Sorry if sometimes I do not get quick answers.  I am not retired yet and some weeks are very busy, just enough energy to go to bed.

 

 

[Mikey98118]

Because the gas pipe is sealed on both ends you can use anything you find handy; even plastic. You are correct that the inner pipe or tube is strictly for streamlining.

Trust the orifice figures on the chart. The other figure is a typo that should have been corrected.

MIG tips of 1-1/2" to 1-3/4" in length are what I consider standard tips; 1" long tips are what I consider short tips. The tip look short in the photo, but perhaps is is just a larger diameter than I'm used too? In such a case disregard what I said.

 

I am not sure what you mean by "... the flame got out on the outside up to the tip..." but I will make a stab at answering your question. If you mean the flame was burning around the outside of the MIG tip itself, than that is almost certainly do to a very minor leak between the MIG tip and the gas tube; it doesn't take much of a leak in that area to do that. If the leak was more than a mere wisp of gas it would be back firing.

The fact that you are working on a precise burner design in an area that presents you with difficulty coming up with recommended materials only quickens my interest in your problems.

[mariom2]

Thanks again.

Will see what comes up with the gas pipe.

The MIG tips I have are regular 1" tips from Lincoln Welders, .025 and .035.  I will try with .025 next time.

 I did not explain well.  You got it, the flame was burning around  the outside of the MIG tip.....you were right there was quite a leak between the MIG and the gas tube.  My mistake.  Will fix it.

 

[Mikey98118]

The tip change will do your burner a world of good, but don't ignore the other upgrades. And just because you may be unable to do one thing for awhile, don't let that stop you from doing other things that you can. We all look forward to watching your progress on the burner and helping you with the forge.

[mariom2]

Today got some free time and did some work.

Got rid of reducer´s lip.

New gas pipe.  1/4" cooper pipe inserted with a cone in the intake.  All silver brazed. Put some teflon in the tip and tested for leaks.  

New MIG tip is 0.025.

Tried a quick test but had trouble firing it.  It backfired 4 times!! I stopped for the time and will try later or tomorrow.

Any reason for backfiring?

 

 

[Mikey98118]

Actually the backfiring is a good symptom;Your burner was too weak to backfire before. A lot of scary symptoms in high speed burners only encourage me nowadays. As to why it is backfiring, look for a leak between the gas tube and MIG tip, just as before. Please understand that, once the burner construction comes closer into line with the book, the smallest leak AT THAT POINT will cause a backfire, once the burner's flow dynamics come into ballpark range of being high speed.

The lip most be completely gone--then bevel the area; yes that will cause your bevel to touch the threads; yes that is necessary, although uncomfortable (I always found it so)

You will find the smaller gas pipe to give better gas flow, but you would still be better off with a longer MIG contact tip, or the addition of an inner liner to reduce the inside diameter closer to 3/16". You can also insert a section of hypodermic needle of the correct inside diameter into the shorter MIG tip to accomplish the same goal.

 

[mariom2]

It is worst.  Very frustrating. Now I can't keep it burning,  and is continually burning back.  Have been changing choke position, tip distance, nozzle overhand but It seems as it just does not like the .025 tip at all.

Checked again, no leaks. Put 1/4" cooper tube as liner in the gas tube, that makes about 3/16" inside diameter.

Maybe the mixing tube size is not correct.  It is 7/8" inside diameter and 8 7/8" from front of air openings to forward cut off end. Chart in page 22 tells you 6 3/4" and your rule of thumb 8 x diameter.  What should be the proper length?.

Maybe what I need is a MIG tip  between .035 and .025. 

[Frosty]

8 x 7/8 = 7 the rule of thumb allows for upwards of 1/2" +/-, say 6.5" - 7". 8 7/8" is way too long.

Maybe what you need is a mig tip between 0.025 and 0.035"? Are 0.030" mig tips not available? I believe that's what Mike uses most often. 

Frosty The Lucky.

 

[Mikey98118]

First, slow down and take a deep breath. Wildly disturbing symptoms when constructing and tuning high speed burners are NORMAL; they don't bother me because I have been making these things for nearly two decades. Of course that seems called comfort to the poor guy experiencing them for the first time, but the truth is that they are encouraging once you understand what and why of air/fuel burner design; they mean that your burner flame is closer to an explosion than a laminar flame. A laminar flame is tame and safe. An explosion is frightening but powerful. A successful burner makes a turbulent flame that is controlled to be just short of an explosion; this is where the extra heat you are looking for comes from. The closer you get to a really hot turbulent flame the more disturbing every failure in flame stability will become.

I use the nine diameter rule of thumb. It is Frosty who uses eight diameters; his burners have completely different flow dynamics from mine. But it is not likely that this difference is  relevant to your your problem.

the 7/8" inside diameter of the mixing tube body is fine for a 3/4"burner size.

The proper orifice size for a high speed 3/4" tube burner is between .031" and 038"; this requires between .023" to .30" MIG contact tips. It is actually rare for the smaller tip to be too small, but apparently you need the larger .030" tip. This is not bad; it is good; it means that you are working on an unusually hot burner. These burners are built from the parts we can come up with; they aren't machined. There will be differences between them. Being a perfectionist, I always use this circumstance to use a set of torch tip cleaners to bore out a few thousands of an inch from the smaller tip. Practical people just use the larger tip size.

[Frosty]

I just stopped saying between 8 & 9 x the tube ID. Mariom asked specifically about 8x dia. so that's what I applied my limited arithmeticyness to. 

I was going to suggest torch files too but realized I was trying to keep quiet.

Funny how like minds muddle the same puddles, I've been describing properly tuned burner flames as uncontained explosions. Usually when talking in person, I can unconfuse folks more quickly that way.

Frosty The Lucky.

[Mikey98118]

Hi, Frosty. Your comments were good. At this point, hearing the same facts put differently from different people should be comforting for him. I know it seems wacko to hear some guy saying that something as disturbing as backfiring flames are a good sign, but this is the dilemma any "expert" must face when speaking to someone who feels like they are in the middle of a crises. If I were him I'd have a strong desire to kick the s--t out of that Mikey character. How can he possibly understand the envy I feel for him, knowing that his moment of crises is just the prelude to a joy I can no longer feel, when he gets to see the magic flame appear on the end of his burner for the first time?  

25 minutes ago, Frosty said:

I've been describing properly tuned burner flames as uncontained explosions.

Yes, exactly; if we refine the description by calling them uncontaminated continuing, or perhaps ongoing, explosions?

[Frosty]

A good sign is only good if you know what you're looking at. One of our guys had made maybe three 1/2" T burners and couldn't get them to work but I couldn't figure out why, he'd followed the directions closely and I'd held one. TILL I saw it running. The sound was scaring him and he kept the psi down to a safe sound. I turned it up to it's properly ear splitting shrieking roar and melted the piece he had in the forge all was good then.

Mariom is doing fine for working solo and talking to some guy on the internet.

I was just watching a couple Youtube lectures about Aerospike rocket engines and there is a proper term for a "continuous explosion" AKA rocket blast.

The Aerospike lectures are pretty interesting, I didn't realize the engine's exhaust has to be almost zero relative velocity when it exits the engine bell or thrust is wasted on open space. Atmospheric pressure is also critical, Bell engines are only efficient at certain barometric pressures and make multiple stages a must.

Oops, getting sidetracked again. but . . . but. . . Frosty LIKES fire!!

Frosty The Lucky.

[Mikey98118]

1 hour ago, Frosty said:

A good sign is only good if you know what you're looking at

How do you keep coming up with those pearls of wisdom? Wish I'd said that (don't worry Mikey you will)

[Frosty]

I reword what other folks say. The principle is used in all kinds of problem solving at one stage or another. Recognize there is a problem. Identify the problem, analyze the problem, devise solutions, adjust solutions till problem solved. And yeah, that's a paraphrase, I don't recall the exact wording from the Chilton repair manual. Motors Manuals were very similar but not what we had on the shelf.

So go ahead, be my guest. Plagiarize my plagiarisms. 

Frosty The Lucky.

[mariom2]

Frosty and Mikey, thank you very much for your replies.  Learning is not easy and it is even more difficult if you work on trial and error.  The reason for posting here at IFI was to get your experience on the matter and I do appreciate all your comments and advise.  They are very welcome.

I am not only learning about burner and forges, I am also learning English as I have to read your posts again and again to understand them with my limited knowledge of the language ....... as you see it is all about learning!!.

As far as I understand  T burners and Mikey jet burners do not behave the same so I guess the wiser will be to follow the nine diameter rule of thumb for now.

I also thought on using torch files to bore out a few thousands of an inch, but the ones I have are so poor in quality that will not make it possible. They bend very easy.  I will try to search locally for a .030" tip but probably if they do not sell the wire then they will not have the tip. Will see what I find.

Just now I will follow Mikey advise to "slow down and take a deep breath" and  will read the posts again to realize if I finally understood the meaning of "uncontaminated continuing, or perhaps ongoing, explosions? "

Mario

[Mikey98118]

I just posted some thoughts on Burners 101 to do with this subject, in which I recast the the problem in different words. Every time you have a chance to see an explanation put differently you are better off to take it.

[Mikey98118]

13 hours ago, Frosty said:

So go ahead, be my guest. Plagiarize my plagiarisms. 

I done already did that

[Frosty]

Mario: You speak American English a lot better than I speak Spanish let alone Portuguese, you're doing great. Helping folk figure these things out is why we're here.

I didn't talk about the T burner to try and get you to change designs!! Don't do that, you're close with Mike's burner, changing now would be nothing but headaches.  Just because Mike and I get lost on a sidetrack conversation doesn't mean we're making suggestions, we're just a couple chatty guys with a common interest. Heck, he lives about 50 miles from where I was born even.

You are doing just fine Mario, Mike'll get you a good working burner just stop trying to hard. It'll come easier, honest. 

20 minutes ago, Mikey98118 said:

I done already did that

I am SHOCKED! 

Darn wool socks on the carpet! You should've seen how high the cat jumped when she nosed my hand.

Frosty The Lucky.

[Mikey98118]

I think it's time for a soap bubble test to sees if there is a tiny gas leak or not.

[Frosty]

Are we talking bath tub soap bubbles? I don't need to test, I know where those come from and it's a good reason to keep a lighter close. Bubble bubble POOF! 

Frosty The Lucky.

[Mikey98118]

Anything with laural hydrate (spelling) in; shampoo, dish soap, etc.

[Frosty]

Sodium lauryl sulfate (SLS) to be specific is a surfacant used in almost anything that needs to mix with water. It breaks surface tension and oil films so water can actually make contact. We used it constantly in the soils lab, about once a week one of us had to mix up another gallon, the lab had a 55 gl. drum in the back room about 1/4 cup to a gallon of water made the concentrate we diluted more and put in the squeeze bottles.

That won't work, SLS is used as an anti foaming agent. Unless it's something like car wash soap the concentration in most liquid soaps is really minute, detergents just need a tiny bit of help they're wetting agents themselves but fast is good getting dirt off.

Frosty The Lucky.