Interesting T burner tuning results

[Paul Kin]

So to start off, I carry a small “bulk” supply of durablanket and kastolite 30 so locals have an affordable supply around. Of corse every once in a while I get the itch to build another forge.... so off the the plumbing shop I go to get the burner parts and it begins! Here is my latest venture: 

Super basic, bare bones gas forge. Easy for anyone to build (I like these because, like myself when I started, beginners often think its hard to build a gasser). This one has a “burner holder tube”. Makes it extremely portable I find. Now normally for this setup I have the holder tube longer so you slide the burner in till it hits and you just light er up! I was short on material this time so Ill just mark the stop spot on the burner for this one. Now whats interesting is how big of a difference it makes where the burner sits! I mean it makes sense now that I think about it cause its essentially making a longer or shorter flame holder I suppose... Now, its still burning off the “whatever it burns off as the refractory cures stuff” as this is the first full heat burn. So theres lots of orange flame of course. I dunno if its my water here or what but I find it takes a good day of work till it cleans up. But heres my results of JUST moving the burner and low, medium, and full pressure on the regulator:

 Now I DO NOT claim to be an expert. And I honestly do not fully understand whats going on here so maybe you guys can tell? Most of you guys have forgotten 10x what I know so Id love to hear your opinions! 

I just thought this was interesting and could be used as a learning experience for others! The ONLY thing changed here is burner position. Mig tip stayed the same the whole time!

Also, sorry for the sideways pictures... I really dont know whats up with that...

[Mikey98118]

If your burner kept that same angle, but in a vertical-down  position; that would be much better.

[Paul Kin]

For general purpose work I agree 100%. I really like this angle for knives though. When turned down, the cool half of the forge is great for heat treating. No worry of over heating the blade! But yes your right for a typical forge the position you suggest is better. Infact the forge Im building for my axe making is exactly like you suggest.

[Paul Kin]

I am really interested in your opinion on why the flame changed so much with just moving the position of the burner Mikey! My only understanding of it is that Im changing the length of the cast in flare/flame holder. So burner pushed in = more combustion in the forge maybe?? 

Another thing to note, noise! At full psi the noise difference is incredible!!! Were talking the difference of needing and not needing ear muffs. At 30psi and burner pushed in, its so screaming loud it sounds like your right beside a jet! Simply move the burner out 1” and it quiets down enough that you dont need ear muffs at all. Now you would never realistically run at 30 psi but it is like that at all pressures. And that, I have no explanation for...

[Frosty]

The main difference in sound levels depends on where the mix is burning. Pulling it back is causing the a greater degree of combustion to occur in the liner muffling some of the sound. Pushing it in is causing more combustion to occur in the forge chamber hence louder.

Yeah, when you have them tuned they are LOUD like a jet engine loud. You can hear a single burner on  my forge in the shop with the man door closed from the front porch of the house better than 100' away. 

You can imagine my delight when I discovered putting one on a NARB quietened it down to the point I can carry on a conversation in normal tones a few feet away.

Frosty The Lucky.

[Paul Kin]

Oh ok! I had a suspicion but didnt want to voice it as I really didnt know if that was the case. I learn so much with every new build its incredible! 

Ya my wife says its loud when shes in the bedroom with the windows closed about 90-100 feet away haha!

The NARB made that much of a difference?!? I understand it should make a difference but if its that much... I might scrap my ideas for my next build and start playing with a NARB. Im going to go through your thread on it again when I have time to concentrate on it. One quick question though, does the 3/4” burner to 350 cu/in rule still apply for welding heat? Im really wanting to try this now!

[Frosty]

Yes, NARB is WAY quieter, one of the things that was such a wonderful surprise, even better than burning stable from stop to stop on my old 0-20 psi regulator. 

Yes, it seems to hold to the 3/4" burner to 300-350 cu" rule of thumb. It doesn't quite for my current NARB forge but I left one side open and forgot to build in a porch to support IFB door baffles.  I have a new and "improved" NARB forge on the drawing board. 

Frosty The Lucky.

[Mikey98118]

Sound waves don't turn corners. If you want less noise, place a baffle wall in front of the opening.

[Paul Kin]

Good to know Frosty! I am going to start going over that thread again tonight. I want to start playing with that fairly soon.

Post pictures of the new and improved when you get around to it! Id really like to see what you come up with! I think my next forge is going to be nearly perfect for axes and hammers (for me anyway) so I wont likely change much there, but I just like building forges haha!

Haha yes yes.. I use bricks for doors Mikey. I find it to be the easiest option... It does cut the sound down as well ya.

[Paul Kin]

Well.. Im stumped... Im starting to think that I have just been getting lucky with tuning and dont actually get what I thought I was starting to sort of barely get... I forged out a quick blacksmiths knife on monday just to finish off the drying of the Kastolite and decided to tune the burner today because this one is causing a lot of scale as is. So yall seen the pics I first posted. Well I started filing back the .035 tip a little (like 1/32 - 1/16) at a time... no visible change In the flame!
 

DISCLAIMER!! OBVIOUSLY DO NOT TRY THIS!!!

So I got curious and I unscrewed the fitting holding the tip. Yes I completely understand the stupidity in this. Anyway, I pulled the tip back... and back... and back! It was just out of the T before it stopped inducing enough O2 to burn. Thats obviously the millisecond my hand on the ball valve cut the propane supply. This was all around forging psi. I dont have a gauge sorry but id guess around 10 psi. Obviously my hands were to busy to snap pics... but there was no real change in the flame. This baffles me because Ive read all these posts on tuning and lots of times it seems that when people trim to far it just wont burn! Thats not the case here. What in the world is going on here?!?
 

So I started over with an .030 tip just to see. It was far more stable a flame at the extreme low psi, like 1/4 turn from off on my 30psi regulator, but it induces more air I would expect. I tried it up to full pressure and worked fine with no trimming. Heres photos of almost off, about 10-15 psi (middle of regulator) and full blast:

But, as I dont want more oxygen and will never run that low of psi I will put the .035 tip back in I think.
 

Im stumped as to why this thing burns so easily but seems not to change when changes are made!?

[ThomasPowers]

I'm a bit confused: excess scale is due to having excess O2; trimming the burner tip back adds MORE O2! Why would one do that to try to get less O2?

Sounds like: "My car was going to fast so I depressed the accelerator more and it didn't slow down---what's wrong?"

[Paul Kin]

Ahhhh and there we have it! I have infact been completely mixed up this entire time!! uuuugh.... well now I know. Thanks Thomas! This is a game changer for me.

[Paul Kin]

Though this is entirely normal for me. Often times when reading things I will not learn a single thing no matter how many times I go over it. I just dont pick up information well that way. But when I find a simple few words as possible like yours Thomas, it makes perfect sense! Im going to write it down “longer tip less O2” and keep it in the shop somewhere. Cause garenteed I will find an explanation with more detail and will mix it up again! 

[Frosty]

Well said, Thomas, thank you for putting it in simple terms. I was under the impression I'd said exactly that in the posted plans and repeatedly answering questions. I'm afraid I'm a victim of the more is better, bug where explaining things is concerned. I'm all too familiar with the TMI effect on the receiving end, a long story before the basic information gets said messes me up too. 

I'm going to have to work on clear and simple directions for tuning the T. Reading the flame and effects is where it gets a little complicated. However this is a case of the terminology I've been using or the way I've been using it, not being clear. 

Not criticizing but this is a perfect example of the reason to not mix plans or build how tos. When something isn't clear, ask the builder to clarify, trying to clarify X's plans by asking Y or W is more confusing.

As you say here, more info is often a good way to kill a chance of success.

You've given me much to think about Paul, thank you. 

Frosty The Lucky.

[ThomasPowers]

Since I have been tuning my "T" burners using your instructions I thought so too; but I've run into folks getting confused by my verbiage before---why I try a lot of simple common object analogies, often cars.  (Though I'm afraid if I use very many more of them someone will open a 'Fund Moi" account to have a scrapped auto dropped from a helicopter on me!)

[Paul Kin]

Frosty, your plans are actually great and very well laid out. Im not saying Im some back country hick... but I just dont take in information through text very well! If I stood beside you and you showed me in person whats what, I would remember exactly and it would be in my brain for good. This whole time I had in my mind the flow dynamics, if you will, of those little DIY hand held sand blasters where the pressurized air comes in half way into the so called mixing tube. I figured the T burner worked like that. Creating a stronger vacuum the further the mig tip was down the tube, therefore drawing in more O2. Which now I see is exactly what it doesnt do!

Thomas, cars I understand! I grew up wrenching on dirtbikes with my dad, or more bothering him while he was wrenching... But its more the mechanical aspect that I understand. Not so much the flow dynamics, though I do have a very thorough understanding of engine operation, exhaust and intake parts I will often just buy vs build.

But all in all, I certainly learned something today! And it actually makes other little things “click” now. I feel like my fluxless forgewelding attempts may suddenly start working out better now. I could never seem to get a very reducing flame. But now I know why!! Thanks guys!

[Frosty]

I don't think you're anything but a guy who absorbs information non-verbally. I have excellent reading comprehension even after the TBI but spoken conversations not so much. I'm with you hands on demonstrations and Q&A rule for learning something new. 

Ah sand blasters and air brushes adjust almost exactly the opposite of a home built jet ejector type burner.  

If you really want to know they whys do a web search for "Jet Ejector". The more effective propane burners tend to be jet ejectors but they are so detuned as to be almost unrecognizable as jet ejectors. 

Jet ejectors are best for drawing a vacuum. You know the giant vacuum chamber NASA uses to test space stuff and train astronauts? Seriously park a 747 hangar size vacuum chamber. The jet ejectors used to evacuate it are the size of semi trailers and can drop the pressure fast enough to simulate sudden pressure loss for large components. 

Frosty The Lucky.

 

[Paul Kin]

Haha thanks Frosty, thats one way to look at it forsure! But ya a live leason beats all. I have gotten people to forge things, in 1 day, that took me the first few years of book learning to do.

Well then... I will scrap those thoughts from my mind!

Ok so I looked up jet ejectors, wow!! I went over dozens of illustrations and I have to say, I feel like I have a much better understanding. I think? I see why you used the T in the orientation you chose. Thanks for the suggestion! 

Thats really interesting about NASA’s test chambers. I actually had no idea they did anything like that! It makes perfect sense they would of course! Ive just never looked into it before now. 

[ThomasPowers]

Test chambers like that are *CHEAP* compared to the cost of lifting faulty components to earth orbit or beyond!

[Frosty]

Every hour with an experienced smith can take the place of days or more trying to figure it out yourself. I like to teach new folks to forge weld in their first session as an icebreaker and confidence booster. 

Watch out, jet ejectors are a terrible rabbit hole! NASA's test chambers are necessary for sure and who in their right mind thinks about how they make so much extremely low pressure? Need to crush some 55gl. drums? Screw the jet ejector into the bung, squeeze the air hose valve and its sucked into a wad. The device is smaller than a paint sprayer. Don't need one though, put a couple cups of water in the drum and build a fire under it, when it's steaming good screw the bung in and roll it off the fire, scrunch!

Anchorage Road maintenance has a lot of storm drains to keep flowing and the truck (the Aquatech was replaced just before I retired) that does most of it is a 7,000 gal tank with a long suction boom and hose. You've probably seen the noisy things at work. (I called it the snorkel snouted sewer sucker, I'm a jokey guy) The hose is about 20" diameter and has been known to plug sucking a large corpse from a manhole. The unit has a compressor that'd drive several jack hammers easily. The jet ejector that evacuates the tank is a little larger than an old VHS tape, wider but thinner than a brick.

Another type jet ejector pumps and cleans bilges on ships using steam as the primary. Steam is extremely effective as primary pressure for jet ejectors, the velocity and pressure passes through the restriction THEN once past cools and recondenses into water creating much stronger vacuum. This allows ships to use detuned jet ejectors which aren't as vulnerable to sucking chunkies. 

As a FYI, 1 gal of 212 water turns into 1,700 gal of 212 steam with the phase shift. The hotter the steam the greater the expansion difference. And of course Earth's atmosphere rushes in to replace the steam when it turns back to water. 

Jet ejectors is a dangerous rabbit hole. Enjoy wonder land.

Frosty The Lucky.

[Paul Kin]

Hey thats an idea... forge welding in the old wood fired/charcoal forge was easy peasy. The switch to gas is still taking some getting used to but now that I actually understand it, things should change. Everyone thats come to me has wanted to learn bladesmithing so other then damascus and axe bits, not a whole ton of welding gets done.

55gal drums hey?? There might be 1 or 6 at work I can play around with... I had no idea! This could get interesting hehe. Of course I will stand back as Ive heard implosions can be unpleasant! 

Boy.. I can see how jet ejectors can be addicting! Thats a lot of different uses that I never even considered. Its apparently a very widespread technology!