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Frosty Burner - help tuning the burner


MatthewMachinist

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Hi, I have finished building a frosty burner, I have spent a bit of time the last couple of weekends trying to tune it, I machined a stainless steel flare with the correct 1 in 12 taper as well. Basically I am having a lot of trouble lighting it, now this is my first burner build but I thought that by making a flare it should make it easier to light. I have probably missed something obvious with this project.

 I started with an untouched mig tig and gradually shortened it as per instructions, I have ended up with a very short mig tip and no success.

So I installed a new mig tip and tried lighting it, I have found that I can light it and "tune it" to a neutral flame when I cover the air intake 75% with my hands.

I am new here so I will tell you I am a Machinist so yes I am a greenhorn when it comes to hot work, except heat treating which I have done a fair amount of.

I have followed the plans closely making sure to use the 0.035" mig tip, the flare means that the burner tube is longer than the 6", I have tried using it with and without the flare and I have tried adjusting the gas pressure to no avail, it lights easier with very low back pressure but then it starts to burn near the mig tip, if I increase the pressure slowly it blows itself out instantly. One difference between mine and the plans is my pipe is slightly longer than 6" and there is the flare as well.

I thought I may have over engineering my nozzle by making it too smooth so I inserted some gauze to try to slow down the gas, still doesn't make a difference.

Lastly I am trying to light it outside of the forge, which should be possible because I am using the flare (as far as I know)

Any help or ideas would be appreciated, here are some photos (the Vernier's are set to 6")

http://s1056.photobucket.com/user/matthewdd3/media/IMG_0579_1.jpg.html?sort=3&o=4

http://s1056.photobucket.com/user/matthewdd3/media/IMG_0580_2.jpg.html?sort=3&o=2

 

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Matthew: I'd love to help you but photobucket requires I disable adblocker and I get maybe 10 seconds before the screen is completely taken over by ads.

If you'll please just attach the pics from the photo files on your computer I can get a look at what you have and give you a hand. It's pretty simple, the link is at the bottom of the text window.

Frosty The Lucky.

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The pics help a LOT. That was WAY too much trimming. Start with the jet about 1/2 way across the intake port. Trim about 1/16" at a time and debur. Light and test it. Take notes of what you did, why and what the results are.

DO ONE THING AT A TIME!  If you change more than one thing you'll never know what change did what and sometimes changes compound. You want to solve these things methodically leave luck as far out of the equation as possible. You wouldn't center a 4 jaw chuck by randomly tightening and loosening the jaws would you? The same technique applies to trouble shooting virtually everything.

The flare nozzles lengthen the mixing tube but the reason they are flared is to compensate for the extra length and add the benefit of lowering the psi in the flow, increasing induction at the air intakes and lowering the flame velocity. 

The step nozzles Mike uses work in the same way sort of and he uses them to adjust the induction rate altering the flame to suit. There are many ways to tune a burner and you can't be changing all of them at once. 

For instance removing the flare seriously reduces the amount of combustion air the burner can induce so the flame gets much richer. Trimming the jet back to 1/8" should increase air induction to close to failure point. Wanting to burn at the jet and blowing out if you increase the fuel psi. says to me you trimmed it WAY to much. 

Relax, take your time and adjust things in small increments one at a time. We'll get you up and running, no sweat and we're NOT on a time clock.

See you when you reply, Frosty The Lucky.

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The mig tip in the photo is the untouched one, If I am hearing you correctly Frosty that one is too short? That would seem to be the case because it is letting to much air in, which would mean I need to find a longer mig tip.

I do also suspect the flare, it does have the correct angle, but I wonder if the length is wrong or if the transition is too smooth. Perhaps Mikey can you tell me your thoughts on my flare, it is the correct taper and the length is 2.375" (excluding the female thread)

One thing I must stress is that I trimmed the mig tips a tiny bit at a time and at no point was I able to get the burner to light, let alone start to tune it. I believe Frosty is right it is just too short, possibly because my flare design is causing it to induce too much air.

So I will look at my options and try them one at a time

- A longer mig tip

- A M Porter style nozzle system

- Altering my flare design

- If everything fails I could add a choke to the air intake I guess.

Thanks Guys, I will keep trying.

Matt.

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Hi Mathew, I don't want to jump in between Frosty and Mikey as they are the experts here, but I think I can save you some time as they seem to be busy today.  I can't get you running perfectly, but I think I can get you started.   Your burner should at least ignite no matter how long or short your tip is, or how your flare is made.  You are not getting gas to the burner IMO.

Do you have a high pressure regulator?

I see you have a pressure gauge, what does it say?

I looks like you have a needle valve, is that true?  Do you know if it works correctly?

Are you sure that the safety shutoff within your propane tank is not activating?

Make sure you do not have a piece of tape or joint paste in the path of the gas.

If you have compressed air, use it to test, remove the propane hose and shoot some air into the brass T, you should be able to feel the air come out of your MIG Tip.

If you have another propane tank try it, I have hit the tank valve lightly on the screw valve handle with a hammer at times, not sure if this is recommended, but it has worked at times on a balking BBQ.

Hope this helps, at least it will keep you busy until the real help arrives.

 

 

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Mike: I don't know what it is.

Stockmaker: What are you talking about? You appear to be addressing things that aren't being discussed? None of the things you list are the problem. Matts problem is too many ideas, suggestions and . . . fixes(?)

Matt. I repeat. YOU ARE CHANGING TOO MANY THINGS AT ONCE, don't even think about them. You are jumping around so fast I don't know what you're asking let alone how to answer. No the mig contact tip isn't too short. Then  again I'm getting confused now, where are the pics of the burner's running? Just the link please.

When you ask Mike about the taper on a 2.375" length. 1:12 maximum change in dia. the length doesn't matter, the ratio does.  

See, you are trying to correct the jet length AND the nozzle flare at the same time. If you keep changing both of them it won't be right unless you just plain luck out.

I don't want to come across as crabby but I'm getting frustrated.

Frosty The Lucky.

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4 hours ago, stockmaker said:

Hi Frosty.  In the post above mine Matthew states that he has never got the burn to light up.  I thought that he was saying never ever did it ignite.  Sorry for jumping in.

I was sharper than I should've been and I don't want to discourage folk from helping.  Matt's been trouble shooting this burner for a while in another thread and I was having a . .  Moment. Heck I could've been thinking of another burner even.

Frosty The Lucky.

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Cheers for the help Guys, I have been doing some tests making sure to change only one thing at a time (thanks Frosty). And yes my biggest problem is just lighting it up. I have tried more than one propane bottle.

On Sunday I machined an extension for the mig tip, the results were that making the tip longer made no difference, I still couldn't light it.

Yesterday I did another test, I put an unaltered mig tip (the one in the photo) in and tried to light it, I couldn't get it to light at any gas pressure from zero to 10psi, there was heaps of gas coming out I could feel it on my hand and hear it. However when I was doing this test I noticed that if I held the igniter approx. 1" in front of the flare it would light. I wonder if having the igniter in front of the flare is slowing the gas down enough to ignite it?

I did a third test, I set the pressure to 2 psi, still using an unaltered mig tip and found that I could light it quite easily provided I cupped my fingers over the air intake blocking off 75% of the air, I then left my hand over the air intake and proceeded to test no 4...

Test 4 - I slowly wound the psi up and the burner stayed lit, however when I approached 5 psi it began to roar which is good I believe, when I got to just over 5psi the flame began to pull away from the burner and it quickly blew itself out.

I hope these tests are clear and paint a better picture for the guys who are trying hard to help me...

Thanks again.

Matt

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Matt: No, that isn't more clear I still don't know what you're doing. A T burner is as simple as it gets and you keep talking about psi, cranking it up down and around. There's NO way you should have to choke a 3/4" T running a 0.035 mig tip. As screwed up as it sounds it should be blowing yellow billowing flames not blowing out.

List the parts for me please so I can see what you're using. 

Frosty The Lucky.

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Matt, are the problems occurring with the burner in the forge or are you still trying to run it with the burner in open air?

On 25/06/2017 at 5:46 AM, MatthewMachinist said:

Lastly I am trying to light it outside of the forge, which should be possible because I am using the flare (as far as I know)

Frosty, I was under the impression the T-burner was only really intended for use in a forge. I don't see any real application for one as a torch, but I could easily be missing something obvious. Have you done any development work with them outside a forge?

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Tim: you can tune a T for a torch if you want. Unfortunately Matt is just plain lost or not listening and having folk making suggestions is only confusing him. I've been trying to get him to stop changing several things at a time and it isn't penetrating. His most recent version of ONE AT A TIME is to alter the psi up and down the scale. Change out jets. Machine new jet adapters and choke it.

NOTHING he's describing will occur if it's even close to right. This burner isn't close enough to tune in or out of a forge. Right now the ONLY thing I think is going to help Matt is a list the parts he used. There is something fundamentally wrong with it. You know what a 12:1 taper looks like yes? Look at that burner nozzle and tell me it's even remotely close. I haven't addressed it simply because the burner is too wrong for the nozzle to make a difference.

Unless he's going to stop shotgunning solutions I can't help him and like I told Stockmaker making suggestions is just confusing him worse.

Matt: please don't think I'm dumping on you, I'd like to help but I'm getting awfully frustrated here.

Frosty The Lucky.

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