Baconchsbrgr Posted April 20, 2020 Share Posted April 20, 2020 Hi all, I'm a newbie who's built a basic forge and have just recently started. I did a lot of research online on how exactly to set up a starter forge and built a passable version of Frosty's T-burner for it. I've fired it up a few times and after some small modifications I have a good heat (as far as I can tell), good pressure, and can work steel with it. My issue came up yesterday as I was working on a piece- the forge sputtered for about a second or two and then went back to normal. I checked the lines, pressure, and amount of propane in the tank (approx 3/8 full) and everything seemed normal. I went back to work, thinking maybe a breeze messed with the airflow for a second (I work outside) and when it happened again I decided to stop and secure the forge until I could figure out what was going on. I do NOT want to risk too much with propane if I don't understand what it's doing. The sputtering looked and sounded like a loss of pressure or a change in the gas/air mixture- I could hear the difference (sounded like the vortex stopped in the forge) and I got 3-4" light yellow flames licking out the mouth of the forge. I do not get dragon's breath on this forge when running normally. The vortex then returned and the flames stopped. My setup has a standard bbq bottle (20lbs?) running through a gauge, 30psi regulator, hose, and into t-burner. The burner is 1/2" diameter, but is scaled down in length to match the math Frosty listed in his diagrams. I am usually running the forge between 11-14psi and an hour or two at a time. At the time that it started sputtering it had run for about 45 min- 1 hour with no issues. No indication of icing; I read tank level at about 3/8th full. The parts are all relatively new so I don't expect to have a worn coupling, hose, or regulator. Not saying I don't, just that it seems unlikely. My question to the group is what's happening here and is it a normal occurrence or something I should watch out for? My initial guess is that the tank level is lower than it should be, I'm losing pressure in the line and just need to refill. With low pressure I get no venturi effect and therefore no air coming in the burner, which would explain the dragon's breath. I assumed the gauge on the line would be correct, but in hindsight almost every gauge I work with at work needs calibration, so why shouldn't this one as well? If it did need calibration, shouldn't it just be a little off, though, and not enough to give me even a warning? At what level do most smiths with gas forges change out their bottles? Erring on the side of caution until told otherwise. Side note: I perused through the forum looking at other problems people have reported with their new forges and burners and I didn't find a thread that quite matched this. I could've missed it, so please forgive me for starting a new one if I did. Quote Link to comment Share on other sites More sharing options...
Buzzkill Posted April 20, 2020 Share Posted April 20, 2020 I'm not sure I have a good answer for you. Too low fuel pressure normally produces a sputtering flame and a whistling/chirping sound which indicates the flame is burning inside the mixing tube. Yellow flames out the exhaust port to me would indicate too much fuel/not enough air. Maybe if your pressure dropped too low to pull in sufficient air you could still be injecting enough fuel to get some lazy yellow flames out the front. I'd actually be a little surprised if using 11-14 psi on a 1/2" burner would cool a tank fast enough for freezing in the supply line or regulator to be an issue. I'm assuming you are using a .023 mig tip for the burner. One other possibility, especially since everything is new, is that you got a small piece of debris stuck in or near the orifice of the mig tip. If that diffused the fuel stream it would certainly affect the air induction of the burner while continuing to dump fuel into the forge. If you start the burner again cold does this happen immediately or only after everything is hot? As for using the fuel in the tanks, I run them empty, or at least to the point where the burner will no longer function. It's far lower than 3/8 of a tank though. Most of the time I can't hear or feel any liquid remaining in the tank when I swap them out. Quote Link to comment Share on other sites More sharing options...
Irondragon Forge ClayWorks Posted April 20, 2020 Share Posted April 20, 2020 It really sounds like the tank is freezing up to the point the propane is not vaporizing well, very common with a 20 pound tank. Try placing it in a container of water to see if it helps. If it doesn't help continue on with Buzzkill's suggestions. I always try easiest first. Quote Link to comment Share on other sites More sharing options...
Baconchsbrgr Posted April 20, 2020 Author Share Posted April 20, 2020 Thanks to both of you. Yes, I'm using a .023 MIG tip. I went with the smaller one to try and keep a better ratio for the smaller burner. I'll check the tip later today when I get back home and let you know if I find any blockage. Didn't think to check that. I haven't run the forge again to see if it would happen when starting from cold; this happened to me yesterday for the first time. I didn't think that the tank was getting cold enough to start freezing... no visible frost at least. I can try the water bath next time I run it. I'd like to upgrade to a bigger tank later down the road anyway, but it's quick and easy to get the 20lb bottles and refill them locally without many questions. I was kinda hoping I wouldn't have to deal with the freezing issues others have faced since I'm not pulling that much propane in the small burner and forge. Quote Link to comment Share on other sites More sharing options...
Mikey98118 Posted April 20, 2020 Share Posted April 20, 2020 5 hours ago, Buzzkill said: One other possibility, especially since everything is new, is that you got a small piece of debris stuck in or near the orifice of the mig tip. This is the answer to the problem, ninety-nine times out of a hundred. The rest of the time it is debris from somewhere further up the line, filtering down to clog up the gas orifice. Quote Link to comment Share on other sites More sharing options...
Frosty Posted April 20, 2020 Share Posted April 20, 2020 Did you use teflon thread tape? The right kind, wrapped the right direction? Frosty The Lucky. Quote Link to comment Share on other sites More sharing options...
Mikey98118 Posted April 21, 2020 Share Posted April 21, 2020 And kept away from the last two threads Quote Link to comment Share on other sites More sharing options...
Baconchsbrgr Posted April 21, 2020 Author Share Posted April 21, 2020 Quick update: took it apart last night and found some of the tape was a little too far down the tip and may have been blocking the opening some. Not sure why it took multiple hours of run time before it became a problem, but that might be it. I also ran a thin needle through the MIG tip to see if there was any blockage there, just in case. No issues with that test. I was home a little late, so didn't get a chance to run the forge, but will do so later this week or this weekend when I have some time. Got a 18-month-old at home, so time is a bit limited during the week... I got a little too trigger happy on the tape; it's the yellow, propane-rated tape, but I applied too much overall and got some comments on that in another post on the forum. Coming back to bite me once again. Quote Link to comment Share on other sites More sharing options...
Frosty Posted April 21, 2020 Share Posted April 21, 2020 Ayup and why I use propane rated thread paste. A little wipe will do ya. Frosty The Lucky. Quote Link to comment Share on other sites More sharing options...
Mikey98118 Posted April 22, 2020 Share Posted April 22, 2020 15 hours ago, Baconchsbrgr said: I also ran a thin needle through the MIG tip to see if there was any blockage there, just in case You are really much better off to use a set of torch tip cleaners ($2 to $4 at welding supply stores). We keep on recommending them, because they are so effective. Quote Link to comment Share on other sites More sharing options...
Baconchsbrgr Posted April 22, 2020 Author Share Posted April 22, 2020 9 hours ago, Mikey98118 said: You are really much better off to use a set of torch tip cleaners ($2 to $4 at welding supply stores). Roger, and will pick up some next time I can get to the store. I've been limiting store visits until it becomes essential due to the COVID precautions. I can also check if Amazon carries them. Quote Link to comment Share on other sites More sharing options...
Mikey98118 Posted April 22, 2020 Share Posted April 22, 2020 Try Amazon.com, or eBay. Quote Link to comment Share on other sites More sharing options...
Irondragon Forge ClayWorks Posted April 22, 2020 Share Posted April 22, 2020 I ordered something from Amazon on April 10, got a reply delivery scheduled for May 9, guess what I ordered is not considered critical. Quote Link to comment Share on other sites More sharing options...
Frosty Posted April 23, 2020 Share Posted April 23, 2020 You can find them in the Wasilla: Alaska Industrial Hardware, Home Depot and Lowes, not to mention the local welding and steel suppliers. One important thing to remember using torch files, they ARE FILES and you can change the ID or worse, MUCH worse, the shape of the orifice. Easy does it and don't stroke it in and out, you just want to deburr the orifice. Frosty The Lucky. Quote Link to comment Share on other sites More sharing options...
Irondragon Forge ClayWorks Posted April 23, 2020 Share Posted April 23, 2020 Even Harbor Freight carries them. (for folks close to a HF) Quote Link to comment Share on other sites More sharing options...
Baconchsbrgr Posted April 24, 2020 Author Share Posted April 24, 2020 I've got a basic set on order; should get it this weekend. If I get it in time or not, I'll be firing up the forge again this weekend so I can tell if removing some of the tape helped out. More to follow... Quote Link to comment Share on other sites More sharing options...
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