JPVT Posted February 22, 2016 Share Posted February 22, 2016 I am in the final steps of finishing my propane forge. I have made a burner based off of Zoeller's Sidearm burner, with some small modifications: namely a customized choke and my own take on the MIG tip assembly. I ran the burner for the first time today in my driveway, and I noticed that it sounded very choppy as I added more and more oxygen. I took a short video as I cycled through the choke, watch it here. https://vid.me/nxoS It was sort of windy out, but I don't know if that's what led to the choppy burn.I have more pictures of the burner here on Imgur. This site likes to delete photos from threads. I was running at around 7 PSI through a Marshall Excelsior regulator. Quote Link to comment Share on other sites More sharing options...
Buzzkill Posted February 22, 2016 Share Posted February 22, 2016 JPVT, I'll leave the diagnosis to guys like Frosty and Mikey, but one thing they will probably tell is this: Pick a burner design that is known to work well and then *follow the build instructions exactly.* Once you start to modify, tweak, or otherwise depart from the original designs you will almost certainly decrease the performance of the burner. While some of these are designs are simple to assemble using easy to find parts and limited tools, the components given are matched up to provide close to the right fuel to air ratio and a hot flame. Unless you have a deep understanding of the design and function of these burners you should not attempt to make modifications. Someone else has already done that homework for you. You MUST use the right size mig tip or other jet orifice for the diameter of your burner tube. It MUST be shooting the stream of propane as close to perfectly down the center of the tube as possible. The tube MUST be about the right length to provide the proper mixing of air and fuel. The air ports MUST allow for enough air to easily flow into the tube. When you modify any of those factors without knowing how it affects the others then you are asking for a poorly functioning burner. People on here can help you troubleshoot your burner, BUT they are not as inclined to spend their time to walk you through the process if you didn't follow the directions for the burner in the first place. The easiest to build burner design I have seen is Frosty's T burner, but even with it care must be taken to assemble it correctly to get a good result. Marshall Excelsior makes a lot of different regulators. Some of them may be compatible with a propane burner for a forge and others are not. Quote Link to comment Share on other sites More sharing options...
JPVT Posted February 23, 2016 Author Share Posted February 23, 2016 3 hours ago, Buzzkill said: Pick a burner design that is known to work well and then *follow the build instructions exactly.* The only *major* change was utilizing a choke that wasn't depicted on Zoeller's site. This choke is based on one found on the school's foundry. The other modification was just for ease of assembly and to ensure (beyond a doubt) that the MIG tip is pointing directly straight. I could understand criticism about the choke mechanism (maybe not getting enough air) but I designed and fabricated this with the help of an experienced engineer. The regulator I'm using is from Hightemptools. Quote Link to comment Share on other sites More sharing options...
Shop Dog Posted February 23, 2016 Share Posted February 23, 2016 I will tell you this, the burners act completely different outside the forge body. Once installed into the forge there are alot of other variables that effect the burner. When making my burner it ran great out in the open, but when installed it started huffing like yours is doing. Quote Link to comment Share on other sites More sharing options...
Buzzkill Posted February 23, 2016 Share Posted February 23, 2016 JPVT, since you got the regulator from Hightemptools it should be fine. I'm not an expert on this topic, but it seemed to me like your burner wasn't getting enough air and/or the propane stream wasn't aimed down the center of the tube well. At 7 psi you should have a good roaring flame with a fairly stable flame cone at the end of the flare. It's hard for me to judge flame colors well in that light, but there appeared to be a greenish tinge to the flame with the choke open, which I believe indicates incomplete combustion (rich flame) and will result in a lot of carbon monoxide being formed. Hopefully Mike or Frosty will help out here. If it's fairly easy to remove your choke system I'd recommend trying it without the choke to see if your flame improves. From the photos that looks like it might be too restrictive even when fully open. Other than that you can play with the depth of the mig tip in the opening which may help pull more air in as well. These are just my guesses from looking at the short video and the pictures, but maybe one of the propane burner gurus will be able to help with the troubleshooting and get you burning stable and hot. Quote Link to comment Share on other sites More sharing options...
Mikey98118 Posted February 23, 2016 Share Posted February 23, 2016 I'm not going to scold you about changing the burner details, but I did notice a couple of things while viewing your video. To begin with, the burner is barely running; that huffing sound is from the flame trying to burn back up the mixing tube, and then recovering as more gas comes down the mixing tube into the flame nozzle, just in time to prevent that. Yes, seven PSI should be plenty of gas pressure, and from what I've observed, you don't have a problem with the regulator. BUT, if you look away from the flame nozzle, and take a good look at the reducer area, you will notice a slightly discolored ripple of gas OUT OF THE side intake. No doubt it was invisible to your naked eye, but your camera caught it. That is where most of your gas is going--it is exiting out of your air entrance. All you have to do to check this out for yourself is to ignite this area, but have a bit of metal ready to to quickly place over that side opening, becuase it is going to be shooting large yellow flames quite a ways out the opening, which wont stop unless you shut off the gas, or smother them by covering the opening. Afterward, remove the choke, because that is almost certain to be causing this problem. Quote Link to comment Share on other sites More sharing options...
Frosty Posted February 23, 2016 Share Posted February 23, 2016 Welcome aboard, glad to have you. What size jet are you using? The build looks pretty sound without being able to get a good look. Yeah, that choke is your problem right now. The only way a choke leaving that limited an air intake area is if you were using a small dia. jet at high psi. and still it's shape is going to induce bad turbulence. You may have seen this kind of choke on burners before but that doesn't mean it worked well. Just because someone CAN get it to work doesn't mean it's a good thing. Put it in the forge, that's where you're going to be using it. Yes? That's where you need to tune it. Breezes can make NA burners sputter too, I have a wind break system I put on mine when outdoors. Before you start removing things turn up the regulator and see how it works. Oh yeah, this is VERY important. Rule #1 of trouble shooting. Only change ONE thing at a time then test run it. Take notes, notes are your friend. Frosty The Lucky. Quote Link to comment Share on other sites More sharing options...
Mikey98118 Posted March 2, 2016 Share Posted March 2, 2016 As to "the burners working completely different outside the forge": That difference is due to back pressure generated within the equipment, which is only going to aggravate his problem; not solve it. Quote Link to comment Share on other sites More sharing options...
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