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T Burner Illustrated Directions


Frosty

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Yes, they do. However, it is good to consider how well flame velocity fits into your individual forge needs. Either higher or lower velocity flames can fit better in a particular forge design. One is not better than the other. But like shoes, a good fit is kinda important :)

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I have had the privilege of thinking about two very hot, but very different burners for about six years now; while thinking about how well each kind does in various forges here on IFI.

I'm loolong forward to thinking about the flames your burners generate for some time, too.

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On 1/24/2021 at 9:34 AM, Another FrankenBurner said:

You want less output from your burner... Tim Allen is frowning somewhere.  :)

Actually, you have a fun line of questioning.  Good for thought.  Most guys are trying to push as much output down the pipe as possible.  This means we are all fighting for as much air induction as possible.  Where you are not demanding the max, you have surplus air.  You could get away with quite a few things that the others can't.  

First, what size forge are you talking about?  Most likely you could run two standard 3/4" burners turned down.  Though, I would follow others advice on that.  I have only played with the 1/2" Frosty T's so I don't know about the turn down range of the 3/4" burners.  

You are branching into your own thing a bit here.  I have used the 023 mig tips in the 1/2" Frosty T's.  You want an in between burner?  You might try the 030 mig tips.  

When you put a burner in a forge, it is pushing through more resistance so it will have a harder time inducing air.  How much so depends on the burner design and the forge design.  I have played with a lot of combinations and most of the time, the change is fairly minimal.  Where you have surplus air, it is nothing to worry about.  You can tune it to compensate.

It sounds like you have gotten it to burn cleanly by positioning the orifice closer to the throat to induce less air.  Nice job.  So long as the fuel air ratio is correct, mixed well, and delivered at a high enough velocity to not flash back into the mix tube, you are doing good on the combustion end of things.  Your ejection velocity will be lower so your flame may ride deeper in your nozzle, potentially over heating it.  If so, you can go to a tighter nozzle like a 3/4" coupling.  

You are correct, the orifice position fine tune's the air volume in the fuel air ratio.  The orifice diameter determines fuel volume in the mix ratio and the total energy output per fuel pressure.  

Could you post a picture of your flame?  I have not tried an 023 tip in a 3/4" mix tube and I would like to see what the flame looks like.  

The forge chamber is roughly 5 x 5.5 x 14", so ±385 in² which is why I'm not concerned with tuning two 3/4" T burners for maximum output, just a great burn.  I was anxious to get the burners installed so I could coat my kaowool interior, so sorry - no pictures of the flame outside of the forge are now available.  My initial findings were with a single burner, and I'd used torch tip cleaners to clean up the .023 tips, so I grabbed some .030's and tried them without messing with them.  I found that they stayed lit outside of the forge, and still required a bit of choking, so that's what went into the burners.  I don't want to waste too much time tuning when the burners have flares on them and they aren't in the forge.  

Last night I used a thin layer of uni-cast 33 to coat the interior of the forge, so tonight, I'll fire it and we'll see where we are.  I like the idea of having a lean burning forge that I can easily choke back the air to get it right.  If at that point, I don't have enough heat, I'll go the route of tuning for larger jets, maybe .035, use my drill style tip cleaners to ream them out a bit.  Gotta be more than 1 way around the barn...

 

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  • 1 month later...
On 1/25/2021 at 1:52 PM, Resinears said:

You are branching into your own thing a bit here.  I have used the 023 mig tips in the 1/2" Frosty T's.  You want an in between burner?  You might try the 030 mig tips.  

There are also MIG tips for .025" wire. .023" tips have .031" orifices. .025" tips have .034" orifices.

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thought i saw this before but cant find it now is a 6in pipe niple 6 with or without the threads 

i cut a old 8 inch tube to 6 1/4 with threads bit it doesnt want to tun well even after trimming the mig tip in half and had a green/ turquise coloured flame surrounded by orange is this too lean or to rich? 

thanks

 M.J.Lampert

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  • 3 months later...

If anyone has somewhat recently ordered a 1/8 MPT fitting online for holding the MIG tip that fights tightly around a #3 drill bit (for tapping 1/4" x 28), and would be willing to share their source (if it's permitted by the forum), that would be hugely appreciated (especially if it's a vendor that can ship to Canada without too much grief).  I just spent most of the day driving around town trying to find one but it seems all the ones available to my local suppliers (I tried ones from 5 manufacturers) are made so they fit a bit sloppy around the bit.

Worst case I figure I'll use one of the local ones and put some pipe dope on the MIG tip threads, but I figure a tight fit for the tap will make it less likely to skew the jet in the tee...

FWIW I'm looking for a 1/8 MPT - 1/4 MPT adapter to fit my system instead of the 1/8 MPT - 1/4 flare fitting recommended in the directions, but I imagine a vendor would have the same diameter inner bores on the 1/8 parts of both types fittings.

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Schedule #80 1/8" pipe has approximately 3/16" internal diameter. We often get so intent on finding just what we are looking for, that we forget all about why  we're after it. Consider how many different things you can use directly as a gas pipe, or internally to come up with the desired internal part within a regular pipe, which you can find to serve this purpose, and forget about fighting border hassles; just a thought :)

If you consider that thread locker or gasket sealant will glue all manner of plastic and metallic parts into water pipe, it becomes much easier to "make do."

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Thanks Mike - it does seem clear I am either over- or under-thinking this :)

Without heading back into town to shop for other ideas, I just realized I have a 1/4" flare to 1/8 MPT fitting I could flip around like the one on the left.  The MPT end is a sloppy fit for the #3 drill bit but the flare end is narrower than the bit, and I could tap the tee with 7/16 x 20 to thread the flare end into the tee.  Because the flare end isn't threaded to the shoulder, it might allow a small bit of air to be drawn in between the tee and the fitting - I imagine that wouldn't have any negative effect on performance but I really don't have a clue about such things...

Wondering if the potential for small air leak on the one on the left would be an improvement over the potential for small fuel leak on the one on the right?

t burner adapter.jpg

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A number of guys misunderstood and tapped the T to receive the flare end of the fitting rather than how I did it. Then the plumbed the propane with appropriate fittings to make up. It works just fine. 

Just don't hang a bunch of fittings on the burner, keep it as simple as possible.

Frosty The Lucky.

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Thanks Frosty - it's great to get some feedback on that, especially from the horse's mouth :).  I feel like I was overthinking, but asking first helps to avoid adding on yet another source of error from deviating from the plans once I put it into the forge and am trying to tune the burners.

Thanks again for making the instructions available!

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  • 3 weeks later...

TLDR: What would be the most likely cause or causes of sputtering/burning in the mix tube or flame blowing straight out in a 3/4" T burner?

______________

Hi all,

I generally don't get to forge more than once a week, let alone work on building my gas forge, which I've been doing slowly, come'n'go style, for about a year now. I've got 2 x 3/4" T burners built with all pieces as per the sizes from the PDF instructions. I've been trying to tune one for a while now (but again, only for a little while at a time with long periods of time in between) and I cannot get it to light without it either blowing straight off the end of of the tube at higher pressures or sputtering and burning in the mix tube at low pressures (sorry no gauge yet). I've been trying to trim a little at a time and check for burrs in the orifice but I'm having no luck.

I will try to get some photos to add this afternoon but is there any, more general advice that I'm overlooking that might cause this?

Thanks,

Jono.

 

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Ok, here's some photos of what I've put together:

The overall assembly

20210810_162016.thumb.jpg.12294371fada9c69849db30c0d754136.jpg

The central alignment

20210810_162040.thumb.jpg.9bc2981c0860de9c5e9ee273ebb150f8.jpg

Where I've trimmed to

20210810_162009.thumb.jpg.0e844b54f7df659326a428609b4f184e.jpg

And the other burner with and untrimmed MIG tip.

20210810_162101.thumb.jpg.71d49d5a59da6db8ef197b3a8fb12ae9.jpg

And yes, I will remove the gal with vinegar before any significant burning.

Cheers,

Jono.

Edit: I've just re-read the PDF instructions. I originally focused on the word "optional" in the heading "Burner flare of your choice (if needed/optional)" instead of "If needed/optional" Could this be as simple as adding a thread protector or pipe coupling flare?

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Hefty: The trimmed mig tip (jet) in your pics is visibly out of alignment. If you don't see it lay a straight edge against the mig tip in the pic in the vise and see how parallel it isn't with the mixing tube. 

It's also clearly out of alignment in the pic looking down the mixing tube. Sure light coming from one side can make it look out but here you can see clearly the end of the mig tip is eclipsing one side of the fitting completely. 

Making the jet aligned straight down the mixing tube is the single most important bit of precision necessary to make NA burners work properly.

Did you deburr the orifice when you trimmed the jet? Torch tip files work best, don't get carried away or you can make the orifice out of round and or enlarged. 

The untrimmed mig tip looks aligned in this pic. try swapping it with the trimmed one. Start with the psi towards the low end and increase it a LITTLE at a time and find where it wants to run. If you jump between high and low you're probably missing the sweet spot in the middle.

Frosty The Lucky.

 

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Hmm, I see what you mean. I just hope it is only the mig tip and not the threading of the brass fitting that has made it crooked in this one. I even used the metal lathe at work in the hope of keeping it central!

I'll try a new mig tip first. Our big box stores don't have as much in the way of steel pipe fittings so I may have to order another T online if that's the problem.

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Ok, so I tried with a new MIG tip and I've almost got it to the point where it will stay lit. It's now huffing instead of sputtering at slightly higher pressure but I noticed, before quickly shutting off the ball valve, that when it burns back into the tube to the MIG tip at low pressures, gas is leaking from around the MIG tip thread. I've been reading that gas thread tape is a no-no in these burners but I presume gas leaking out near the air intakes (apart from being unsafe) is going to affect its ability to induce air. So, any advice on how can I stop the leaks?

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Your presumption is correct.   The mig tip is a stream shaper.  We want that fuel to be in a fast collimated stream down the middle of the mix tube.  The mig tip is also a metering device.  It only allows a certain amount per pressure.  

Right now you have an uncontrolled amount with who knows what kind of shape, potentially causing all kinds of turbulence.  Too much fuel and not enough air.

Until you fix it, there is no point in attempting to tune.

 I have used gas tape and thread dope.  Both work.  I'm not sure of the reasoning that you read against tape.  Perhaps because if it is installed incorrectly, pieces of it can make it into the gas way and plug the orifice.  If you go the tape route, make sure not to tape beyond the last thread on the orifice inlet side.  

Nice job.  You are getting close.  Soon you will be thinking about shaping metal instead of about burners.

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I don't know what called me away, I had a reply written but it's dated now so I'll write another. 

While a lathe is nice, it's not essential by a long shot. A drill press works more than well enough, you don't need  to use a floor flange and nipple to align everything if all you need do is tap a brass fitting. I use the drill bit that fits the fitting most snugly chucked in the drill press. I slip the fitting onto the drill bit and move the drill vise till It will clamp onto the wrench faces on the fitting without moving it. I check again after clamping the vise to the drill table of course.

Once the vise and drill are aligned you can chase the fitting and tap it using the drill press as the tap wrench until its started well enough to finish by hand. With the vise aligned it's easy enough to chase and tap several brass fittings and keep them in the box for later use. 

I keep my burner parts including: pilot bits and taps, pre tapped brass fittings, a broad selection of mig contact tips and torch files in a cigar box. Then again I find myself helping local guys make and tune T burners.

When I make a burner I clamp a floor flange to the drill press table with a close nipple screwed in tightly enough it won't turn when I tap the T. I keep everything in place until I've tapped and checked the mig tip. It keeps everything aligned straight down the mixing tube. 

Remember do NOT run the tapered pipe tap too deeply into the T or the threads will be too wide to hold the brass fitting in place. I marked my first tap (long lost <sigh>) with paint at the correct depth. This is the most common mistake. 

You are NOT locked into using 1/8" pipe x 1/4" flare fitting. One of the guys in the club couldn't find one so used a 1/4" flare x 1/4" flare, coupler and tapped the T to match. It turned out the through holes in these tend to be small enough to tap or chase to tap more often than what I used originally. 

A 1/4" x 1/4" flare coupler doesn't care how deep you tap the T, it's a straight thread and you simply screw the fitting in till it's REASONABLY tight. Be careful it's REALLY EASY TO STRIP, there aren't many threads the Ts are so thin.

Franken Burner and Buzz made good suggestions, no bones to pick from me there.

Frosty The Lucky.

 

 

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Thanks for the replies!

AnotherFrankenBurner, I'm glad to hear that people do use thread tape here because that will be my easiest fix. I'll have to try and find where I was reading about not using it and see if I'm missing something in context.

Frosty, I am using a 1/4 x 1/4 flare coupling :) I understand your instructions on the drill press. I think the issue was just the mig tip itself but I remember when I drilled and tapped the Tee I wasn't sure if the shape of the fitting was true enough to rely on for centering. I'll keep an eye on alignment once I get new mig tips thread sealed in both burners.

Cheers,

Jono.

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Regular teflon thread tape degrades in the presence of propane so it's a NO NO! GAS rated thread tape is stable but isn't recommended as it's common to get scraps in the gas line where it can foul and plug things you want to keep clear.

Folks building a propane appliance for the first time are rarely likely to know how to keep tape out of the gas circuit so we recommend thread paste.

Frosty The Lucky.

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Sorry, yes, I meant gas rated tape.

I know not to use normal teflon tape with gas but that is probably what I read/mis-read elsewhere about not using thread tape with burners.

I understand what you mean about scraps blocking things up and I'll follow AFB's instruction with the thread tape not past the last thread. For the amount I need, the thread paste is almost 10 x the price of the tape.

I'm getting close. I can feel it!

Cheers,

Jono.

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