natenaaron Posted August 19, 2016 Share Posted August 19, 2016 I have made two forges. One was too big for the 3/4 inch T burner by just a smidge. I built another one for 2 3/4 T burners which should be over kill. I put a 1 inch T burner in the smaller forge and that should have been complete overkill. Neither forge will get a piece of metal past bright orange almost yellow. Both forges have the same 2 inches of ceramic wool blanket capped by 1/4-1/2 satanite and two washes of ITC-100. After questions here I made the necessary changes and even completely blocked off the front and rear doors to see if that helped get things to a higher temp. Nope. All that happened was the outside of both forges got screaming hot. 2 things I have noticed. Number 1-After running the smaller forge for about 30 minutes I swear the 1 inch burner is spitting unburned LP. in the middle of the flame hitting the metal it looks just like a drop of water is hitting the metal then goes away, and does it again a few second later. My assumption is the tank is freezing up. I was in full sun and the temperature was 106 that day and the tank was in water so I have no idea why. it is a 30 lb tank. I have had a hard time finding a two way connector to daisy two 30 lb tanks together. Supposedly this will help Number 2 My heat is going elsewhere. When I say I closed the forges up I mean I only left enough space for the 1/2 square bar to hang out. Totally closed up with hard brick other than that Only part of the floor of the larger forge is packable refractory and the rest hard brick. I believe the hard brick is sucking the heat away. No hard brick in the little forge but man that thing got hot, so clearly my heat is escaping Conclusion I messed something up and I am going to try again. This time a lot more research and zero thinking. Only follow the recipe. grrrr. Quote Link to comment Share on other sites More sharing options...
Frosty Posted August 19, 2016 Share Posted August 19, 2016 How many cu/in and what are the shapes of the forges? A 1" burner has the same output as two 3/4" burners. What are the details of your burners, tube, dia and length, intake area, jet dia, etc.? Frosty The Lucky. Quote Link to comment Share on other sites More sharing options...
natenaaron Posted August 19, 2016 Author Share Posted August 19, 2016 CU/IN = 362ish and 620ish 1inch burner = 45 tip, tube length 8 inches, 1.25 inch/1 inch T. No idea what intake area means 3/4 inch burners are built to your 3/4 inch specs on the nose. Quote Link to comment Share on other sites More sharing options...
Frosty Posted August 19, 2016 Share Posted August 19, 2016 Those are the right ratios mostly. Intake area is the area of the intake ports. Pi R sq. x2 is the area of the intake of a T burner. I use a different, easier calculation. .7854 D sq. it's accurate to IIRC 8 decimal paces but it confuses a lot of folk so I stick to the old school calc. A few cu/in shouldn't be enough to not make temperature. A 1" burner in a 360 cu/in chamber is WAY overkill. I don't know about the strange driplike effect once it comes to temperature though. You DID'NT use Teflon tape anywhere on the fuel lines did you? It shouldn't have been freezing your tank either, not that quickly. You would've had to be giving it really high pressure to start the propane slushing up that fast. Frosty The Lucky. Quote Link to comment Share on other sites More sharing options...
natenaaron Posted August 19, 2016 Author Share Posted August 19, 2016 I don't have a regulator but this was no where near high pressure. Yes, way overkill and not getting where it should. I should be burning up metal in that thing. I'm not, so the heat is going some where. I thought out the doors so I sealed them up. little hole to put the steel through and still nothing. So going to start over. I got Mike's book in the mail. I'm reading it closely. I hate not being able to do what I want and not being able to figure out what I did wrong. By the way, if anyone is reading this and has a mind too, Mike Porter's Burner book is well worth the money on amazon. Quote Link to comment Share on other sites More sharing options...
Michael Cochran Posted August 20, 2016 Share Posted August 20, 2016 How do you know it's not high pressure? If you don't have a regulator are you not running at full pressure of the tank? I suggest getting a regulator before bad things happen. Quote Link to comment Share on other sites More sharing options...
natenaaron Posted August 20, 2016 Author Share Posted August 20, 2016 Oops, should have said Pressure gauge. Long week. I'm tired. I have a HP regulator. No tape on any connection, only pipe goop. Quote Link to comment Share on other sites More sharing options...
Latticino Posted August 20, 2016 Share Posted August 20, 2016 As regards the description of your larger forge: Make sure you have a thermal break between the forge interior lining material and the forge casing. By thermal break in this case I mean a layer of high temperature insulating material. If you have either hard fire brick or castable refractory (not castable insulation) touching both the forge interior and the forge casing you make a thermal bridge between the two locations and the heat you are trying to keep inside the forge will conduct out to the forge casing where it will be lost to the atmosphere. Please note that the insulating value of castable insulation can be determined from the manufacturer's data on the material ("k" value for thermal conductivity, lower is better). Most castable insulation is not as good an insulator as high temperature blanket or board. It can be used, of course, but you need to use a greater thickness to achieve the same level of insulation and the forge will likely heat up more slowly because it has a greater thermal mass. Note that this extra thermal mass can be useful, but that is a lecture for another time. For your smaller forge, are you sure that all the flame from the burner outlet is making it's way into the forge interior? If you have a gap between the forge insulation and the liner, and the burner head is too far out of the forge some of the flame can get directed to the gap, and not in the forge (and the forge casing will get hot). Look carefully when you light up, a full developed blue flame should show inside the forge past the insulation. Also, on installing blanket it is certainly possible to crush it down too far when applying satinite, which lessens its insulating value. Go gentle next time and consider spraying a colloidal silica layer on the exposed blanket first to stiffen it before the refractory coating. Quote Link to comment Share on other sites More sharing options...
Mikey98118 Posted August 21, 2016 Share Posted August 21, 2016 Nate, I get the felling that there isn't anything seriously wrong with your forges. I have seen burners and forges greatly discourage guys, when all they really needed was a little more tweaking. I think that is where you're at. To begin with a burner based on a 1" pipe in one of my designs runs a little lean with a .035" MIG tip, and a little rich with an .040". I usually run the smaller tip after using a file from a set of torch tip cleaners to enlarge it from an orifice diameter of .044 up to a diameter of .046"; a few minutes work. You stated that you're using an .045" (meaning a tip that is made to run .045" welding wire); such a tip has an orifice diameter of .054". I don't think that a Frosty "T" burner runs that different from my design... Next you state that the 1" tube's length is 8" long, but a 1" pipe has an inside diameter of about 1-1/4", making it 2" short of Frosty's preferred eight diameters rule pf thumb, and 2-1/4" short if you go by my preferred nine diameters rule. Changing these things might make your burner performance quite a bit better. As to your exhaust openings: You can't close down the opening too much without creating massive back pressure on the burner. The small opening for stock left in a brick wall is supposed to bounce back IR energy; not reduce exhaust flow. Move the wall far enough from the forge shell to allow exhaust to flow between it and the wall. Think of that wall as a baffle, and the space between it and the forge shell as the proper exhaust opening. How much space? start with the baffle 2" away, and adjust from there. And, do be sure to paint the hot face of the wall with a high emissive coating, such as ITC-100. Quote Link to comment Share on other sites More sharing options...
Frosty Posted August 22, 2016 Share Posted August 22, 2016 I run my 1" T burners with a 0.045 mig contact tip for a jet but I have the orifice more than half way up from the center of the intake port centers. The farther from the tube the more air it induces. The T is a 1"x 1 1/4" or 1" x 1 1/2" depending on which one I was messing with at the time and I have to admit I haven't built a 1 burner in a long time. I'd rather run multiples. Frosty The Lucky. Quote Link to comment Share on other sites More sharing options...
Mikey98118 Posted August 22, 2016 Share Posted August 22, 2016 Each Mikey burner has a "sweet spot" at a particular distance between the MIG tip's end and the end of the air intakes; they vary, but are easily noted, since too much or too little distance greatly diminishes performance. Quote Link to comment Share on other sites More sharing options...
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