Thady Posted September 13, 2018 Share Posted September 13, 2018 Hi all finally finished my forge and burner. Never built anything out metal before and this is my first attempt at stick welding so please dont laugh at my welds. I havent really pushed it yet but it manages to get the steel yellow and pretty low pressures. And it is extremely controlable its not sitting in its final home yet. I plan on moving the guage and needel valve to a safer place with metal plumbing in between. Critisism very welcome. Quote Link to comment Share on other sites More sharing options...
Mikey98118 Posted September 13, 2018 Share Posted September 13, 2018 That looks like your burner is getting pretty hot to me. One thing I see is a very wide gap between the burner's mixing tube and the tube used for a burner portal; that will allow the flame to induce a lot of secondary air into the forge. Excess secondary air only lowers forge temperatures. If you made your own large flat washer to slide down the burner's mixing tube, you could then wedge it in place at various heights and watch its effect on the flame; when to see when the amount of secondary air is optimum, or you could drill holes in the washer, while watching for the best flame. Quote Link to comment Share on other sites More sharing options...
Mikey98118 Posted September 13, 2018 Share Posted September 13, 2018 Excess secondary air? Yes; most burners produce secondary flames; such flames are unlikely to combust completely absent some secondary air introduced into the forge. So, if your burner doesn't have a perfect primary flame a little secondary air will help the forge run hotter and cleaner. Quote Link to comment Share on other sites More sharing options...
Thady Posted September 13, 2018 Author Share Posted September 13, 2018 There is a ss reducer on the end of the mix tube that is exactly the right size for the mounting tube those perfectly evenly space bolts actually clamp on the reducer not the mixer tube, next to that is the wool and i have also moulded refractory into a nozzle that the flare sits on to isolate the metal from the flame so although its apparent that there is a space its all pretty well sealed. I will post further pictures soon. Quote Link to comment Share on other sites More sharing options...
Mikey98118 Posted September 13, 2018 Share Posted September 13, 2018 Good enough. Quote Link to comment Share on other sites More sharing options...
MotoMike Posted September 13, 2018 Share Posted September 13, 2018 It looks like a very nice build to me. I've packed the space between my mixing tube and burner mount with kaowool, rigidized it so no air can go that way. also, I started with one row of burner mounting bolts and after one mishap realized I needed a second row which I installed. the second set of mounting bolts really secures the burner rigid. Also, I think it was Frosty who alerted me to the chimney effect the burner has when the forge is just shut down. I have a choke cap that I routinely close right after forging to keep the air flow and heating of the jet tube to a minimum from super heated air rushing back up the burner. Don't know if this is critical, but It is part of my routine. Nice work Quote Link to comment Share on other sites More sharing options...
Thady Posted September 13, 2018 Author Share Posted September 13, 2018 I place a little bit of metal on the choke to stop heat rising up. I managed to get it hot enough to make mild steel bend like lead under it its own weight today. Quote Link to comment Share on other sites More sharing options...
timgunn1962 Posted September 13, 2018 Share Posted September 13, 2018 Which jetting did you get? When running on Propane, I find the Butane jets actually give a slightly higher flame temperature than the Propane jets with the choke fully open (it's fully open in the first pic in post #7). You have sufficient control with the screw adjustment on the choke to go as much richer/cooler as you could ever realistically want to with either jetting, just by choking down the burner. The Butane jets are a bit smaller and give a "less-rich" mixture, though still somewhat rich/reducing. The factory jetting is based on industrial burner practice and almost certainly works on the assumption that there will be significant secondary air. Assumed/design working pressures are in inches water column, though I regularly use them up to 4 bar/60 PSI. Quote Link to comment Share on other sites More sharing options...
Thady Posted September 14, 2018 Author Share Posted September 14, 2018 I fitted a 110 jet as recommended by the guy who gave me the design. When i first fired it i used very low pressure 1 or 2 psi to gently heat the refractory with the choke half open i was get a green primary flame which at first i thought.. wow thats cool, then i read here that a green flame is over rich and belts out massive amounts of carbon monoxide. so the choke has been pretty much wide open while adjusting the pressure. It seems to run along at 5psi and gets seriously hot at 10-15. I have a thermocouple being delivered in the next few days so i can get an idea of how hot as i have no real basis for comparison. Quote Link to comment Share on other sites More sharing options...
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