T Burner Illustrated Directions

[Frosty]

That might be okay, the reduction might be fare enough down the mixing tube it won't cause turbulence. Yes, beveling the inside of the 3/4" pipe will improve performance, you don't want to disrupt the laminar flow of air/gas in the mixing tube. The propane jet provides enough low pressure and toroidal turbulence to mix propane and air. By toroidal flow it's very much like a continuous smoke ring in the mixing tube. It quickly converts into a tornado like vortex as it flows down the tube. All this turbulence is smooth and actually increases induction forces at the air intakes. 

A sudden step from wide to narrow can't help but disrupt laminar flow and inhibit induction. 

It's hard for me to imagine you can't find a 1" x 3/4" T at a dedicated plumbing supply, I don't know of a house or building that doesn't use them. I thought I lived away from a city. Many of the big box stores don't carry them but they're pretty common, even here.

Frosty The Lucky.

[Mikey98118]

So, to directly answer one of your questions; no, the possible problem isn't hard to fix. Simply unscrew the mixing tube and reducing pipe, and bevel the inside surface of each part's rear edge.

Before you even ask; no the bevel job doesn't need to be perfect. You are making a simple fix, to pick up an easy  increase in performance. "Don't worry. Be happy"  

[BayardStrachan]

Thanks Mikey and frosty. And to answer frosty. The only way I can get a 1-3/4 reducing T is to order it online for exorbitant prices. I don't know of a building that does use threaded iron pipe. It's all PVC or copper in NZ I think. 

[Frosty]

Uh HUH, do you live on the opposite side of the planet or something? 

It's easy to forget we do live on opposite sides of Earth. I'm wondering how hard it'd be to make the T portion of the burner from copper. I'll have to take a look next time I'm in the corner HVAC/Plumbing supply. 

Frosty The Lucky.

[BayardStrachan]

yah, i managed to find a pile of 1 inch fittings in a back corner of a shed. which was lucky 

[BayardStrachan]

what abt a burner flare too, in the plans its optional, how do i know if i need one?

[Frosty]

It isn't really a matter of "needing" a flare, done right they help in a couple ways. They act as a flame holder or sorts, the increase in diameter causes the fuel air mix to slow down and the slower the flame the longer the hang time in the forge where it does work for you. The other real benefit is improving induction and Mike has a neat trick for fine tuning the flame by moving the flare in or out.

Will a flare help? Yes. Will it help enough to be worth the extra work? Don't know, this is where trial and error comes in. 

The more work comes with tuning the burner for a neutral or slightly reducing flame with the flare. A flare changes things so you have to tune for it.

Frosty The Lucky.

[BeezerOH]

Hello, new here and we just finished building our first gas forge with two  3/4" T burners. Thanks, for the design Frosty!  The directions were easy to follow and we took about 1/16" off the tips each time to get them burning.  We need help with tuning the burners. We do not have nozzles on them yet as we are having a hard time locating the thread protectors. We do have good hot flame and loud roar from both. The front seems to be running rich but we don't have the experience of reading the colors and patterns. I can tell you that we have alot of propane smell from the forward burner when it is burning and it is not as hot as the rear burner. Appreciate any help with diagnosing these flames as rich or lean.

[Frosty]

welcome aboard Breezer, glad to have you, if you put your genera location in the header you'll have a better chance of meeting up with a member living within visiting distance.

You can smell propane while it's burning!!!  That is B-A-D! Have you checked all the fittings and connections for leaks? Swab with soapy water. PLEASE make sure nothing is leaking before you start it again, the ONLY time you should get a wiff of propane is if the wad of paper or whatever you light it with goes out when you turn the valve on. 

I can't tell too much from the pictures but what little I can see looks pretty close. Let me see a pic right after you light the burners too and one from the side of the forge so I can see what is coming out the openings.

We'll get you tuned, you look to be pretty close now.

Frosty The Lucky.

[BeezerOH]

I leak checked the lines and all is good now. Here are the other pictures. Sorry my phone isn't the greatest for pics. We get a high flame creep oit of the front, too big of an opening?  Of these aren't any better I'll get someone else to take the pics instead of wasting time. Appreciate the help!

 

[Frosty]

Those pics show what I need to see, Breezer. It looks to be burning a LITTLE rich but not bad. What psi are you running it under? That is a really long flame. How far is your burner extended into the liner? 

You are down to trimming the mig tips with sand paper and torch, tip cleaner to de-bur the orifice. Forget measuring it, You're within a few thousandths now.

How did you make the burner port through the liner? It's pretty easy to shape the ceramic blanket with rigidizer and castable refractory into as good a burner flare as there is. That lets you do a little fine tweaking by moving the burner itself in and out a LITTLE bit. 

Frosty The Lucky.

[BeezerOH]

It's burning best at 6-7 psi. The burners extend 1/8" or less past the liner. The burner port is 1-1/2 black iron pipe welded to the case and tapped for 4 bolts to hold the burner.  The gap between the holder and the burner tube is blocked with blanket. So for the nozzles would you just roll up or build up the ceramic blanket with rigidizer with the 1:12 flare or do we need to start over with the main blanket to do that. Sorry, newbies here. And we will fine sand and de-bur the nozzles to get it tuned up from here. 

One more, how do we know if we get it too lean?

[BeezerOH]

Pictures are easier to explain it....

[Frosty]

Ahh, one of my pet peeves arises! Jargon is a craft language of defined terms and words so everybody knows what a person says without having to ask for clarifications.  "Port" is the entrance or opening a thing enters through.

A burner port is the opening in the forge the burner and flame enters the chamber. What you're describing is the burner "Mount" a thing that holds an object. Make sense?

Your burner "Nozzle" is extended into the chamber! It should just enter the liner, less than 1/4" is plenty of penetration. That's just past the shell. The steel tank, cookie tin, welded box, etc. is the shell. All it does is contain the liner and support the weight of forge and work. 

If you pull your burner back until it's 1/4" or less into the liner performance will improve and your burner will last WAY longer. Open the burner port through the refractory liner to approximately 1" Dia. for a 3/4" burner. Do NOT try to match the ID of the mixing tube. Close to the OD is preferable so the liner can act as a step flare. 

When you make the port through the refractory you do NOT want to leave it bare ceramic fiber, even rigidizing is NOT sufficient so make it about 1/4" larger in Dia. Rigidize and finish with castable refractory. From just past the burner nozzle taper the port slightly, no more than 1:12, less is fine, more becomes problematical due to turbulence. 

This turns the forge liner into part of the burner and makes the burner flare more than 2" long which is way better than some of the commercially available screw on stainless steel flares. What makes is better is two fold. Made carefully so the inside is smooth and tapers at the right ratio it improves combustion air induction while slowing flame velocity which keeps the flame inside the forge longer to do work for you. Secondly it moves flame contact from the mixing tube nozzle into the refractory flare which is designed to withstand up to 3,000f flame contact. That makes your burner mixing tube last much longer. 

Make sense?

Pull the burners back where they belong and we'll evaluate the flame again. Right now the length of flame, dragon's breath and low psi. says your burners are running rich. Do NOT mess with the mig tips now! Pulling the burners back and refining the entry ports WILL make a big difference in performance so trimming the mig tips now would get lost in the changes made to the liner, you could very well have to replace them and start over.

Frosty The Lucky.

[Mikey98118]

3 hours ago, Frosty said:

while slowing flame velocity which keeps the flame inside the forge longer to do work for you.

Good point!

[BeezerOH]

Yep, it makes sense, hence why we are getting so much heat being transferred upward on the burners. I'll need to source the refractory to make the nozzles and work on that before doing any other adjustments. Might take a while. Any suggestions on what to use?  I'll dig into the refractory topic as well. Much obliged!  Will likely need you again before this over.

[Mikey98118]

I can't think of any better choice than Pistix 900 for this purpose, or a more convenient one to order in small quantities.

[Mikey98118]

Frosty,

Is it about time to bring up idler circuits again? We have all these people racing to get their forge built, so as to heat their shops before old man winter makes them unhinhabitable...

[Frosty]

Sure go ahead, I've never used one  so I'm not the guy for this job. 

Frosty The Lucky.

[Mikey98118]

But, but, but, I envisioned you falling down that rabbit hole...er, ah, I mean leading the way. Yes, that's what I meant

[Frosty]

Sorry Mike but I've been a disappointment so many times I've lost count. I suppose I could figure an idle circuit out but I've never seen the point. I don't turn my forge off during a session except maybe to eat, lunch run errands, etc. unless it's off much more than an hour it lights right up when I crack the gas and comes to temp in a couple minutes.

Got another rabbit hole? I've been messing around with knapping recently, want to talk about that?

Frosty The Lucky.

[Mikey98118]

Oh, I think it is like so many other things in life; useful to some, but not to others.

For instance, I adore them, because I'm a cheap skate; but I don't actually use them, because they go out the door on the equipment given away, to make room for the next series. Does this make sense? When did I ever make sense? At 76 it way too late for tiny stuff like that

Yo, Frosty. Kathy and I just celebrated our 50th. I never expected to even see 50, let alone keep up a commitment for half a century! So, what is the main spice of old age? I think it's irony

[Frosty]

Understanding what  you're talking about and making sense aren't the same thing. Not at all. 

You know you aren't that far west of some good obsidian sources and obsidian is pretty easy to knap. Hmmm?

Frosty The Lucky.

[Mikey98118]

Between writing and gardening, there's no time left for other hubbies. Not that knaping wouldn't be fascinating, but it takes I just a focus to get anything done these days. I just wasted two years on a burner book, which must be shelved, because the incredible greed of merchants of materials for its construction has made these burners impractical. Fortunately, there is a previous book about very different burners, which that same greed has made more practical then they appeared back then

1 hour ago, Frosty said:

Understanding what  you're talking about and making sense aren't the same thing.

Being right will do for me. Making sense is really asking too much of myself

[Frosty]

But but it's so much fun to point out when you make a mistake! So many other folk think you're calling them names if you point out a mistake. You're a lot more fun that way.

Frosty The Lucky.