Shaggycanuck Posted November 4, 2019 Share Posted November 4, 2019 I've recently decided to build a small forge as a compliment to my other metal working. Traditional blacksmithing wasn't a priority, I was more interested in adding annealing, heat treating and some hot work (bending, twisting, etc.) to my projects. To that end I started reading up on forge and burner design here and elsewhere. I've built two 1/2" burners and a preliminary forge shell which after fitting the burners and test lighting one, I'm beginning to think are mismatched. The finished size with lining was going to be 4" round by 16" long. I'm still waiting for my refractory material and co monitor so I moved on and finished my burners. Instead of raiding my mig welder for tips, I turned mine from 3/8" brass round with a multi angle tip and 1/8" npt threads, the holder was made from 18ga sheet metal and the extra holders that come on my pellet stove ignitors, the rest of the burner turned out to be a 1" by 1/2" reducing coupling, 1/2" by 8" nipple and a 3/4" by 1/2" reducing coupler. I came to this from starting with ideas and some math from here and elsewhere plus a bit of trial and error as I worked through different variables one by one. The jets are drilled #61 which I worked up from the original #70 I drilled. I'm wondering where I should be in forge size with these, in particular a D shape seems appealing. Here's a pic of one of my burners running in open air. Quote Link to comment Share on other sites More sharing options...
Glenn Posted November 4, 2019 Share Posted November 4, 2019 That gas burner heats up the stove from across the room. It should work well once you build a forge around it. Quote Link to comment Share on other sites More sharing options...
Mikey98118 Posted November 4, 2019 Share Posted November 4, 2019 Construction wise, it's a good burner. Design wise the burner has several mistakes. Fortunately, the mistakes can be eliminated one at a time, if you are dissatisfied with performance in the forge. A "D" shape forge is a good fit for burners with excess secondary flames, so continue on that path. Also, be sure to allow a generous amount of space around the burners for secondary air to be sucked into the forge; you're burners are going to need it. Quote Link to comment Share on other sites More sharing options...
Shaggycanuck Posted November 5, 2019 Author Share Posted November 5, 2019 (edited) Thank you Mike, I just did a quick test after work and the secondary air requirements are definitely a problem. To run with my 30psi regulater tapped out I needed to hold the burner 3/4" outside the shell to draw enough secondary air in. Not really a solution in my mind but proof of the problem. What would you suggest as parameters to play with? I'm not adverse to building another set of burners for the forge I'm working on and doing a D shape forge for these ones. The tinkering is pretty enjoyable! There is no reason to quote the post just prior to your reply. The quote feature Edited November 5, 2019 by Mod30 Remove excessive quote. Quote Link to comment Share on other sites More sharing options...
Irondragon Forge ClayWorks Posted November 5, 2019 Share Posted November 5, 2019 Welcome aboard... Have you read this yet? READ THIS FIRST It will help you get the best out of the forum with tips like editing your profile to show your location and other tips to stay off the moderators radar. Quote Link to comment Share on other sites More sharing options...
Mikey98118 Posted November 5, 2019 Share Posted November 5, 2019 If you make the burner opening at least 1/2" lager diameter than the burner's mixing tube, the burner's flame should induce sufficient air to burn the fuel left over from the primary flame. More air than holding the flame away from the forge entrance for sure. Quote Link to comment Share on other sites More sharing options...
Shaggycanuck Posted November 5, 2019 Author Share Posted November 5, 2019 That worked very well, I changed the tip out to a 1" by 1/2" from the 3/4" and it runs to full steam while in contact with shell. I'll enlarge the openings and build new burner holders tomorrow if things go well. Thanks again! Quote Link to comment Share on other sites More sharing options...
Shaggycanuck Posted November 17, 2019 Author Share Posted November 17, 2019 Finally received my refractory materials and was able to move ahead. Mistakes were made and fun was had. I put my linear burner design aside and played around with laminar flow in an ejector design to induce more primary air. I won't put up a pic of it because although safe in a vertical position, in horizontal it absolutely is not. The second burner port is plugged with left over insulation, two 1/2" burners running 0.025 mig tips is too much. The rear door can't be used and way to much external flame. I rejetted this burner by giving it a crush to a true 0.025 with a collet. Temperature wise on one burner with the door closed my IR thermometer would only greet my with a Hi which is 1200f and above. So I ran it with my test piece behind the flame and was able to hit critical (non magnetic) on both the coupler and rebar, performed a brass melt but was not successful with copper, only melting what was close to the flame (this was with the richer jet last night). Pic 1 is warm up running 15lbs Pic 2 is melting brass at 10lbs Pic 3 is scale formation left is the brass melt, right was last night with richer jetting. Pic 4 is forge opening with rear door closed. Pic 5 is with rear door open. Pic 6 is for the CO safety guys, 2.5' from forge. Quote Link to comment Share on other sites More sharing options...
Irondragon Forge ClayWorks Posted November 17, 2019 Share Posted November 17, 2019 16ppm for CO is relatively low, however for folks that have health problems and are sensitive to CO, it will/can cause headaches. I would increase the ventilation because long term exposure is not good. Quote Link to comment Share on other sites More sharing options...
Frosty Posted November 17, 2019 Share Posted November 17, 2019 Ditto, CO exposure is cumulative and takes a considerable amount of time to be flush from your system. If you're a smoker you're living with low level CO exposure so even a small bit extra can be significant. I know when I smoked I felt the CO lip buzz a log time before other guys around me, at the forge or other such efforts, the road maintenance crew had a number of pieces of equipment that had darned rich burners under them, the patch truck asphalt pan for instance. My sensitivity to CO went way down after I quit smoking but it's back up or I notice it sooner since the TBI. Frosty The Lucky. Quote Link to comment Share on other sites More sharing options...
Shaggycanuck Posted November 18, 2019 Author Share Posted November 18, 2019 I was dosed once 30 years ago due to a rotted muffler on a grain auger. stumbling out of a building is not something I'd like to repeat. More ventilation and less production are in the program. On another note, I used my collet trick on the other mig tip and got it down to a true 0.025 ID, I'm now running on both burners with the door closed with some room to tune mixture by damping. Quote Link to comment Share on other sites More sharing options...
ThomasPowers Posted November 18, 2019 Share Posted November 18, 2019 It's that time of year to start hammering on the CO warnings for folks in the Northern Hemisphere! I for one do NOT want to attend any estate sales and buy large anvils and powerhammers for a pittance from grieving folks left behind! Quote Link to comment Share on other sites More sharing options...
Jon Kerr Posted November 19, 2019 Share Posted November 19, 2019 Especially since the detectors are so cheap! Even the ones with an LCD display are dirt cheap on eBay (£5-12) from known brands. I highly recommended the LCD display, as it allows you to keep an eye on the levels all the time. My coke forge seems to be variable on what I can get away with. Some days, I can forge with just the two windows open in my shed (at 0PPM) which will keep my neighbours happy by reducing the noise. Other days, I watch the level creep up and have to forge with the door open to keep it at 0 PPM. Perhaps depends on the atmospheric conditions, draw on flue, etc etc. Looks like the OP has this all covered with a decent detector. Forge looks great (though I know nothing re/ gas forges). Quote Link to comment Share on other sites More sharing options...
pnut Posted November 19, 2019 Share Posted November 19, 2019 (edited) At one of the hotels I work at the exhaust ducting in the laundry where I spend most of my time was in need of a good cleaning and I started to notice I would get a headache and feel generally ill whenever I worked at that location. We have since gotten CO detectors for both locations and cleaned the exhaust and I haven't had the problem since. Don't take even low levels of CO lightly as it will cause problems after continued exposure. As frosty said the effects are cumulative. Pnut Edited November 19, 2019 by pnut Quote Link to comment Share on other sites More sharing options...
Mikey98118 Posted November 28, 2019 Share Posted November 28, 2019 BTW, nice flame and nice forge. Two thumbs up Quote Link to comment Share on other sites More sharing options...
Shaggycanuck Posted November 29, 2019 Author Share Posted November 29, 2019 Thank you, it's come a long way since the first idea was hatched. Found a couple weak spots, burners should be closer to each other and the shell should be larger diameter to give space to improve the refractories but it works and 10psi seems to be the sweet spot for forging with it. Now's it's on to building an anvil stand. Here's the finished forge and my first flux spoon. Quote Link to comment Share on other sites More sharing options...
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