MatthewMachinist

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

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.

Sorry for the late reply and thankyou for offering to help In the meantime I tried taking one of the mig tips and shortening it down to around 1/8" long, still no joy. In the photo above the mig tip that is in the actual photo is the untrimmed one.

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