Burners 101

[Trevor84]

Hey all been awhile, been dealing with stupid neck and back and SC pinches and and and way wah issues so I haven't even kept up to date with these threads so please excuse my just jumping in with a quick question. 

I'm not ready to do up a stand alone post but this is a slight twist on the ol' RR ez burner. 

I'm feeling this is a fairly decent flame, if dimmed the exposure so the colors are the same as what my eye sees. 

I've built several burners and had a thumbs up on the glame/burn/combustion I'm getting however I haven't seen this thin almost neon blue line. It's not just the photo or a filter, it started to appear as I adjusted the mixing tube and over hang of the nozzle. 

 

Am I right is this decent combustion, is the thin neonblue line a good sign or irrelevant. 

 

1 1/2" - 3/4" bell reducer 

3/4"-1/2" rigid conduit reducer bushing my slight twist 

1/8 sch 80 fuel supply to the 0.023 mig contact tip

4"x1/2" mixing tube

1"x3/4" sch 20 spacer in a 3/4" merchant coupler (straight thread not pipe) for the nozzle. 

 

The rigid conduit has a smooth rolled lip the creates a slight restriction and sits right at the base of the bell or throat. I would like to hear thoughts on the science, I know laminar isn't always the goal but maybe this will encourage a smother faster vortex? It's like adding the rolled edge from a coffee carafe to the lip of a 2L pop bottle and then doing the child's  cyclone experiment with colored water maybe? 

 

 

 

[Trevor84]

I finally found a place to order these wye fittings, I think my jet is crooked but you can see how the rigid conduit reducer bushing sits inside the throat on this other burner.

[Frosty]

That line is just a sharp demarcation between one burn zone and another and an outstanding indication of an excellent build. You might be able to tweak the air fuel ratio a little but she's beautiful right now.

You can see all 3 burn zones clearly so it's a flame I'm liking. Mike should chime in and we'll see how close I am.

Frosty The Lucky.

[Mikey98118]

3 hours ago, Trevor84 said:

Am I right is this decent combustion, is the thin neonblue line a good sign or irrelevant. 

No; it is excellent combustion! Congratulations. You win two blue ribbons; one for each type of burner

[Frosty]

A pun, on Thursday Mike? 

Until you convinced me you don't need to see three or even two burn zones a flame like the above example is what I strove for. Since then I'm perfectly happy with a pale blue soft nearly neutral flame that's REALLY HOT.

I still like to look at beautiful things.

Frosty The Lucky.

[Mikey98118]

On 3/24/2022 at 5:01 PM, Frosty said:

Until you convinced me you don't need to see three or even two burn zones a flame like the above example is what I strove for. Since then I'm perfectly happy with a pale blue soft nearly neutral flame that's REALLY HOT.

And I haven't changed my mind about a single blue flame envelope being the goal. However, the shape and amount of sharpness of that flame envelope will differ with different burner designs, because of different mixture flow dynamics. I not only don't consider this a problem, but favor it as an opportunity. No single shoe fits all

And you influenced me just as much with your views about practicality trumping perfection. So, I now see a truly hot flame that is nearly neutral (but slightly reducing) trumps a perfectly neutral flame in all heating equipment.

[Mikey98118]

Tube Cutting

 

Cutting parts to length is most easily done with an abrasive disc mounted in a cutoff saw (AKA chop saw); the cheapest are about $140. On the other hand, surface cutting parts to length with a rotary tool or die grinder requires a proper cut line; this can be provided with an ink marker and paper rolled around the tube or pipe, instead of a pipe wrap. Then proceed to make the cut in the manner recommended in the Surface Cutting section below.

    Or, you can mark perfect cross lines, at true right angles, with a cheap little pipe cutter; it can also be used to completely sever the parts. But for parting, you will need a quality tool; it will cost double the price of the cheapest tool, but with reasonable care, will do the job for years, without breaking (don’t attempt to cut deeply with each pass; take your time).

    Separating parts this way will bend the inside diameter in the immediate area of the cut line several thousandths of an inch smaller; this can be quite handy with oversize choke sleeves, and some spacer rings. Otherwise, the inside of the part area might need to be ground or sanded to restore the original inside diameter.

 

RIDGID - CC247 RIDGID 40617 Model 101 Close Quarters Tubing Cutter (1/4” to 1-1/8”); $21.28 through Amazon.com is recommended for parting.

 

Surface cutting air openings and slots in parts: If you stop the disc during a plunge cut (with a circular or a chop saw) before the cut is finished will usually cause kickback. The opposite is true when surface cutting on sheet metal products, like pipe and tubing. Attempting to remove a moving rotary tool or die grinder from the kerf will usually cause kickback.

    Those OEMs (like Dremel Tools) who bother with a thorough list of safety tips in their instruction manuals, all advise the operator to run a cutoff disc back and forth on the part surface, gradually deepening a groove at the cut line, until the disc begins to break through the groove, which is then called a “kerf.” Unlike chop sawing or plunge cutting through thick parts, the operator is supposed to bring the disc to a halt before exiting the kerf; it is different to other cutting processes, because your disc isn’t deeply buried in the part. There is very little material for the disc to “walk up,” creating an opportunity for kickback, as the disc stops. Also, the numerous tiny grit edges don’t have anything like the tendency to grab unto stock that the teeth of circular blades do. Most kickback from resin bonded cutting discs come from the sides of their discs binding against the kerf.    

    So, surface cutting creates a unique situation, where stopping the disc before removing it from a groove or kerf is safer than removing the disc while it is still in motion.

Die grinders are treated the same as rotary tools for surface cutting (my own description of this technique).

    You will notice that friction makes the disc want to move in one direction; take note of it, and make sure that the disc is traveling in the opposite direction, when breaking through the kerf. Otherwise, the disc will tend to bump against the end of the kerf, creating kickback.

 

Maximum safe RPMs of cutoff discs vary by manufacturer and thickness; if a marketer doesn’t list the maximum RPM for a cutoff disc, the rule of thumb is not to use larger than 1-1/4” diameter generic disks at 32,000 RPM, or 20,000 RPM for 1-1/2” unrated generic disks.  

    Brand name rotary cutoff discs (ex. Dremel), and discs used in electric die grinders (1/4” and 3/8” arbor holes) are typically much higher quality, and are designed to run at higher RPMs than generic rotary tool discs. A 25,000 RPM rating is typical of 3” die grinder discs, and 30,000 RPM for 2” die grinder discs.

    Stop the cutting short of drilled corners, when using a new cutoff disk; save that last 1/8” at the beginning or end of your cut line for a smaller diameter used disc, or a 15/16” disc (without fiberglass reinforcement); most of these small discs are only 0.025” thick jewelers discs (ex. Dremel's #409), which should be doubled to run in steel. Dremel also sells inexpensive thicker #420 discs, which are much better in steel than doubled thinner discs.

[Mikey98118]

12 hours ago, Mikey98118 said:

However, the shape and amount of sharpness of that flame envelope will differ with different burner designs, because of different mixture flow dynamics.

To make things clear, I have enlarged the flame photos and it only confirmed that that is total combustion of a primary flame. The fuzzy outline of that flame is still part of it; not the beginning of a secondary flame. How can we know that? The darker blue tint of the flame insures that it is right next to oxidizing; not reducing. These flames will probably end up being slightly de-tuned in the forge, to keep scale down.

On the other hand, the burner with a Wye fitting has the lighter blue of a neutral flame that is closer to the reducing side. Neutral flames have a very short range of adjustment between oxidizing and reducing.

[Mikey98118]

The Dremel 575 Right Angle Attachment is noisy and should only be used for small tasks in short bursts, with some speed reduction; it heats up with continual use. You can open its case and apply a small amount of white lithium grease to the gears, to reduce noise and heat buildup.

    One customer found that loosening the screws that hold the plastic case together—a little bit—reduced noise. He concluded that the case wasn’t perfectly formed, and that it was causing drag on the movement in one area of its rotation. If his solution is followed, thread-locker showed be applied on those screws, to prevent them from unscrewing further.

    The attachment can be locked at any position on a rotary tool; this provides increased accessibility in hard-to-reach areas. What this attachment is particularly good at, is providing superior access and views for surface cutting on flat work; also, for the forward and rear cuts of air openings in small diameter tubing, using 15/16” cutoff discs.

    Push the 1/8” shank of an accessory completely through both holes near the spindle, after lining them up with the internal shaft, to lock the drive, before tightening or loosing accessories—do not use the spindle lock on your rotary tool with this attachment; that would put great strain on the square coupling spring, which is this attachment’s weakness.

    You will notice that the plastic nut that tightens this tool down on your rotary tool’s neck has knobs and is larger than you would expect; that is so that you can hand tighten it sufficiently to keep it in place during use. Dremel also provides adequate instructions for mounting and using their attachment.

        There are lookalike versions of this attachment; avoid them. The 575 comes with a collet, nut, wrench, and drive nut to replace the collet nut on your rotary tool.

   

[Trevor84]

Excellent combustion, woohoo! I think I know what you're saying about a neutral burner wanting fine adjustments, a lean/oxidizing is a lot isier to detune to get neutral. The burners I've built that start out neutral always seemed to ride a fine line with the A/F

 

Now it's the game of getting it to balance out in the forge atmosphere. I added a spinny choke plate thingy for warm up, cool down and mid session tuning, I fiddled with the nozzle  over hang and angle the burner enters the forge and depth the nozzle sits. The burner is mounted 1/3 from the entrance but angle backward just enough so the flame can almost corkscrew to the back, the AF is combusted inside the forge with minimal pressure being forced out either end 

Here the little bird box I'm finishing up for a couple friends. have little touch up's needed to the refractory and I think I may smear some of the ITC 100 I have in there but she's a cooker now! 

 

The burner will run stable at the bottom of my regulator all the way to full throttle without belching dragons breath or sputtering. I haven't spent enough time with it to say much more than that. 

[Trevor84]

[Mikey98118]

The flame is fine, but the flame retention nozzle needs to be backed up into the refractory. Not out in the forge interior.

[Frosty]

Looking good Trevor. Ditto what Mike said. Pull that burner way back, just into the liner is perfect. 

Get that refractory blanket covered as soon as possible!

Frosty The Lucky.

[Trevor84]

Hmm it's definitely an angle perspective thing. The nozzle overhang is 1/2" past the end of the mixing tube and the nozzle tip is about 1/2-3/4 inch up into the port once at heat the flame sits in the 1/2"  between nozzle and forge interior. 

The blue lines are the wall of the burner port. 

 

The refractory broke up as I was refining the ports and reefing the burner about... It is allready patched and waiting for the next step 

[Frosty]

One of the serious problems with having your burner so far into the liner is transferred heat. The liner becomes incandescent in use and the heat conducts back through the liner. This WILL heat your burner past a temperature that will pre-ignite the fuel air mix inside the mixing tube. 

The hotter the mix the faster the rate of propagation so the flame front moves closer to the source.

In my experience extending the burner nozzle no more than 1/4" into the liner has prevented pre-ignition. Much farther and prolonged use almost always causes it to burn back.

Frosty The Lucky.

[Trevor84]

I have the nozzle set to a depth where the lip of the nozzle may get red but no further back..... I pride myself on the flame originating from a black hole..... I try to balance the over hang and increase in diameter with the port in the insulation/refractory ie liner so the flame starts between the lip if the nozzle and lip of the port though the refractory.

This forge body was quite small so on the walks the insulation is only 1"-1 1/2" thick so 3/4" UP into the liner is closer to the 1/4" down or 1/4" INTO the liner. 

 

I'm not arguing just trying to describe what my eye is seeing vs what the image shows.... I'll see if I can find pics of other hot port shots (that's 'pg' right) 

[Trevor84]

Hmm I had a few videos saved on one of my phones but I can't find the ones I was thinking if. Anyway i do try to set the balance up so the flame sits between the lip of nozzle and lip of forge liner interior.. 

This birdbox will be on forges 101 after I finish up with the ITC 100 and other refinements to the burner port and 

[Frosty]

That thin a liner will transfer more heat faster. There's a reason the general consensus of a number of people with years of experience building propane forges is two 1" layers of 8lb. ceramic blanket refractory and a castable flame face refractory preferably kiln washed with a hard firing high alumina kiln wash.

My 1st functional propane forge has 1" kaowool outer and 1/2" hard refractory inner liner. It was powered by my 1st functional T burner, I think #3-4 experiment. It reached welding heat easily but within an hour the outside of the shell was hot enough to toast anything flammable that came in contact for any length of time. 

I rarely ran it that long because the burner started back firing about then. That forge is under a bench in my shop, long retired as is the burner but it gets a spot on a shelf in a locker.

I'm not trying to harsh on your accomplishment. I'll probably see about copying your burner, she's a 4 star all the way. 

Your forge needs work not just a few finishing touches. I'm not going to try explaining anymore. You're misplacing your pride I can't do anything for that. 

Frosty The Lucky.

[Trevor84]

Wow ouch, I got no problem with pride nor I'm I struggling to comprehend the basics of building a forge. I've been here 6 years reading your explanations and instructions and sharing your information I was just explaining that the burner wasn't into the forge interior. I honestly don't know where/how you and Mike came up with that. 

 

I feel like there's a constant misunderstanding between us which really sucks because I really respect and appreciate your knowledge. I don't even care about this forge I was just trying to discuss the build not challange your knowledge. 

 

You and Mike said up in the liner wich I confirmed then you say only a 1/4" into the liner from outside..... We're going back and forth over less than a half an inch but again all I did was say how it was positioned in its port. 

 

 

 

 

 

 

 

[Trevor84]

Seriously I'm not trying to argue, I only corrected the fact the burner wasn't I side the forge. 

 

I'm going to stop joining in, I am exhausted with the misunderstandings every time I try to reply. 

[swedefiddle]

Good Morning Trevor,

I am not hearing any arguing. I am hearing Mike and Jerry answering the same questions and remarks, over and over. They are trying to suggest, how to make your Forge better. There are an awful lot of questions, you need to answer on your own. Myself, I like to pay attention and try something. Make little changes, only one at a time (then you know if it helped or not). I keep a log book of all my designs, what worked and what didn't seem to. I go through my Log Book, now and again, to see if something will change, with another new change. I call it 'Research and Development'. Never cast off all thoughts, when you are working on something new.

Yes, sometimes, you just need to keep some thoughts to yourself. The problem with the keyboard, it is really difficult to read the other person's facial expression(s).

Good Luck with the Forge. Remember!!!!! Only make one change at a time!!!!!

Neil

[Trevor84]

The only thing I didn't agree with is whether or not the burner was inside the forge or liner. It's not arguing or dismissing its explaining. The dang picture was taken from an upward angle, and its obvious the burner is inside a hole/port. 

 

I'll read the information shared here but I'm not going to spend three days explain a picture. 

Maybe it was when I said 1/3rd into the forge..... I meant front to back not 1/3rd into the forge. 

All these pics are the burner at the same depth. 

OK the insulation along the back wall is about 1 1/2", peak is 2" maybe 2 1/2", the wall opposing the burner is close to 2" the floor is 2"

 

There's give or take 3/8" castable and then there will be an IR top coat. 

 

The burner sits inside the port in the insulating a scooch, it's too small to get a good look or to even feel the depth so I have to judge by how the flame is igniting.  I set the depth while watching the balance and yes I try really hard to have the flame light just inside the port in the insulation/refractory. 

 

Everything that I've learned here I've used, Mike has talked at length about using the nozzle to superheat the gasses before they enter the forge... I believe that concept is repeated on Chili's website.....I use the port in the insulation for this not my nozzle, my nozzles stay black, maybe a lick of red maybe but that's it and at the end of the day. 

 

Yes Mike a Frosty are on repeat, it's too bad, my forge isn't actually 1" thick, the nozzle isn't inside the forge and I don't know what else to say, 

 

I don't know but here's a couple more pics, if the forge still needs a LOT of work then that's great it's a heck of a lot close than it was when it was dropped off. 

I will stop replying to these threads and just read, this is ridiculous. 

Here's what a burner inside a forge looks like, this is what was brought to me. 

[ThomasPowers]

And now for something completely different!  It's spring time in New Mexico and so the winds are upon us---yesterday gusting to 50 mph; but not as bad as the year we had a constant 80mph straight line winds; so far.

So any suggestions on wind screens for Frosty T burners?  I need to take my forge to teach in slightly over a week and the spot has a roof but open walls and wind can be an issue.  I usually take a piece of sheetmetal and lean it against the mixing tube; but was wondering if any more elegant solutions were out there? 

[Trevor84]

1/2" T burner, hole in the bottom of an all tin coffee tin 

[Mikey98118]

Trevor,

Your forge is far from perfect; it is also far from worthless. Keep using it. After a time you will probably decide to "reach for perfection," as we all do. When you build your perfect forge, keep this one around, for you will go right on using it at times.

I think the placement of the bricks to form a roof is not only clever, but provides an excellent flame path within the forge. The path to excellence is to keep what is worthwhile and to change what isn't.

Yes, Frosty and I agree with each other on most things. Sometimes one of us is right, and then the other must accept his point of view, because both of us are doing our best to speak the truth, as we know it . Would you rather it was not so?