Mikey98118

Actually, the photo says it all; this will never be more than a second rate burner. Why? Because the pipe reducer being used as its conical shaped air intake does not even provide a two to one reduction in diameter with the inside of the pipe being used as the burner's mixing tube. You need at least a two and one half reduction in diameter for a linear burner to come alive, and a three to one reduction is desirable.

More on rotary tools Hand held rotary tools become more valuable all the time, but, avoid their variable speed versions like the plague. Yes, it is handy to be able to vary the RPM on a rotary tool, but you want to do that trick by plugging it into a separate speed controller, like those made for routers; the reason is that the circuitry is too delicate when they are mounted in the rotary tool itself, and so they burn out quite easily. Single speed rotary tools cost so much less that you can often buy the router control for the price difference, and not only end up with a much tougher tool, but one that has a wider speed range to boot. If you cannot avoid buying a variable speed version, you are still better off to run it at full power and use a router control to vary its speed; saving wear and tear on the tool’s own circuitry, and better controlling its speed in the lower RPM range. Accessories have been improved even more than the rotary tools have. Cutting disks were originally made to create very thin cuts in rings and other soft jewelry items; many still are, but steel cutting friction discs have been perfected, along with the spring loaded mandrels they mount on. Dremel’s EZ Lock mandrel, and EZ Lock 1-1/2” cutting disks allow you to make delicate internal cuts for air openings in burners, and quickly do all the cutting needed while shaping forge shells, or cut angle iron for equipment stands. A Set of diamond coated burrs replaces hand files; they are fast, easily controlled, economical. Unlike rotary files they do not fling needle sharp debris. Drum sanders (the mandrels) use abrasive sleeves to slip over an expandable rubber drum; they are hard to beat for smoothly removing a few thousandths of an inch, to make tubing or pipe parts fit. The best design for small drum sanders use a bottom nut for tightening instead of a top screw.

Well, yes and no. Mostly no; that view is mostly incorrect. Can I always create an oval, "D", oe tunnel forge that is more efficient than a box forge? Yes; however, will it be a lot more efficient? NO! Will it be superior enough to offset the limitations built into those other designs? Probably not for a shop forge. If the forge is indended to be move to job sites, they would be. The biggest problem with your present forge is its burner. The second big problem is a hard firebrick floor. Change the burner first, and the floor next. By the time you get around to looking for more improvements, your dissatisfaction will probably not justify bothering with anything further As to your forge burner, what Frosty said sums it up; "They aren't very good but not awful." It would be easier to explain what is especially right with this burner, rather than list everything they got wrong: nothing is right! No, it isn't awful, but it will never put out those critical last five-hundred degrees needed to bring your forge interior into high incandescence. Without that added input, your forge will remain a mere gas oven; not a radiant oven. That last twenty percent of heat input will double the forge's working output.

Your photo makes what is wrong with that forge obvious, and it is the burner. Either buying or building a burner is the first step to improving this forge, or replacing it with a better one. However, a proper burner is likely to solve most of your problems with the present forge. So, get smart and stop thinking about replacing the forge, without knowing that you actually need too. Think "better burner for my forge."

Well, yes, but within limits. More than a three to one constriction ratio between funnel entrance and the mixing tube's internal diameter is problematic. The limits also apply to shortening the conical air entrance. A sixty degree cone is a better shape than a forty-five degree cone. The shorter the cone the worse the problem. So, why say probably? I have observed the problems that accumulate with forced-flow burners, but free-flow burners are more subtle; nevertheless, an obvious, repeatable, event in one type is likely to show up in some degree in the other type.

Do not feel lost,Guillaume. Your friends have the right idea, but "the devil is in the details." I don't want to devil you, so I will admit that I got one of those details wrong; that would be the size of your burner. So, just ignore my question, and wrestle with less pesky details. If you're happy with the burner, than so am I

Hi, Guillaume Love to see your use of sheet metal in forge construction. I just advice guys to use old gas cylinders, tin cans, and pots. But that is only because, sheet metal is very expensive for an American who doesn't live near a scrap yard, so learning how to use sheet metal isn't an inviting prospect these days. As to the photo showing the air entrances and gas tube on your burner. One of the earliest improvements made on burners, was to square up the forward and rear ends of slot shaped air openings. The second improvement was to bevel the forward and rear edges of those openings; both changes greatly increase air induction into tube burners. The result is way hotter burner flames. The thicker the tube wall the more important beveling is... Your gas tube looks way too long. While some tube length is needed to increase the speed of gas molecules leaving the gas orifice, how long that needs to be depends on orifice size; the smaller the gas orifice the shorter the gas tube needed. Also the smaller the inside diameter of the gas tube the smaller the tube can be. However, there is a "sweet spot" where the gas orifice is at the best distance away from the forward end of the air entrances to induce maximum air into the burner. I estimate that to be about 3/16" on that burner size. Are you employing a .3mm 3D printer nozzle as a gas orifice, or some other size?

It should be about time for people to ask some questions, to help them finish their garage and barn warmers...er, I mean forges, before icicles start forming on the eves

Why 1/4" and 3/8" burners? The only equivalent commercial source to small burners are standard dual-fuel torch-heads, which will last fast as a hand torch being run on MAP fuel (polypropylene), and even faster mounted in heating equipment, even when only run on propane; the problem in both instances is their paper-thin flame retention nozzles. At high heat levels, which are obtained with (polypropylene) burning in the open air, and with propane burning in a forge or casting furnace, even a stainless steel flame retention nozzle will oxidize away over time; the thinner the nozzle the less time that takes. Flame retention nozzles must be considered as a consumable item; the thicker they are the better. The thin none-replaceable nozzles on commercial dual-fuel torch-heads are simply a rip-off. So, using a dual-fuel torch head in your two-brick or coffee-can forge isn't going to be the cheap and easy path, unless you think replacing them, instead of just a flame retention nozzle is going to save time and money! An even worse choice, is using one of the older propane torch-heads, with a brass flame retention nozzle, laid in an over-size burner opening (to keep it from melting); this saveS the torch will wasting lots of expensive fuel.

What does a hot efficient forge take? (1) Good design; this starts with size. Make the forge no larger than your present needs--not as large as you suppose you could need, eventually. Shape is also a concern. Your forge should be no longer than one and a half times its width, and about two thirds as high as its width; these proportions apply to tunnel, "D", oval, and box forges. The best shape for a first forge is variable (brick pile forges). Burners should have sliding air chokes on their mixing tubes, so that the amount of secondary incoming air, which the burner's flame is inducing, can be controlled. The speed of exhaust gases exiting the forge should be controlled with a baffle wall, while radiant energy is reflected back into the forge. (2) A hot and efficient burner; while this is certainly an important part of any forge, you will note that it is secondary to good forge design. A miserable burner cannot properly heat the best gas forge; but a merely average burner can do so. How is this possible? A proper gas forge becomes a radiant oven, once heated. Any carbon monoxide gas (secondary flame) Is quickly consumed within the forge, so that only hot exhaust gases escape the forge--not flame.

Frosty covered things pretty well. I would only add that your next step should be a brick baffle wall in front of the forge, to allow stock to pass through, and exhaust fumes to escape upward between its near side and the forge, while bouncing back radiant energy into the forge's interior. You will find that it saves you plenty of fuel, and glare in your eyes. For this wall, you are better off to use plain old hard clay firebricks, and coat their forge facing sides, just like the forge interior. Once you add a baffle wall, that forge should use about one-third gallon of propane per hour, at welding heat. There are other steps you can take to reduce fuel used, like adding an idler circuit to your forge. However, most people with a small efficient forge, just don't bother going that far

Well, this is one those times that the video actually showed me more than the stills First; I noticed a shorter flame than usual; is this from installing a Hybrid burner sans its flame retention nozzle, is is the gas pressure turned way down? Either way the flame looks perfect in his forge. The second video shows how rapidly the forge is heating up; and this with it running wide open at both ends . If nothing else he now knows that his design is a success.

Slit spacer rings There are two different reasons to slit a slide-over stepped flame retention nozzle’s spacer ring: One is simply to decrease its diameter, so that it will fit within the flame nozzle’s outer tube; in that case the socket head set screws will be drilled and threaded through the outer tube and the spacer ring together, and then a set screw is screwed through both parts, one at a time, to keep the outer tube and spacer ring from moving out of position, during the work. Tolerances can leave you with loose fit-ups at times; in this case use electrical tape to center your parts within each other, and to keep them from slipping out of position while you drill and thread them for permanent fit-up. The tape will burn out of flame nozzle during the burner's first firing, changing nothing once the parts are trapped together by socket screws. The second reason is to allow it to become a constricting spacer ring, in which case the socket head screws are only drilled through the nozzle’s outer tube.

After years of watching others aim their flames toward the far side of the floor, from burners positioned at at ten or two oclock, I am persuaded that it is the better choice.

Slide-over stepped flame retention nozzles So far, slide-over stepped flame retention nozzles do a much better job of controlling the flames of high-speed air/fuel burners than tapered nozzles ever did; they are a necessity for fan-induced linear burners. These nozzles consist of one pipe or tube, called a spacer ring, fitted into an outer stainless steel pipe or tube. You are likely to have to power sand the outer or pipe or tube, or the spacer ring, to get them to fit together. You might even end up slitting the spacer ring lengthwise, before pushing it into the rear section of the outer tube. Or, you could just as easily slit the spacer tube, and spring it apart, to provide a snug fit to the outer tube, and a sliding fit on your burner’s mixing tube. The spacer ring can be made of either stainless steel or mild steel, to suit your convenience. But the outer tube must be made of stainless; #316 stainless is better for the purpose than #304, as it does not oxidize away under high heat and live flame conditions as fast. However, #316 doesn’t last enough longer than #304 to put up with the high prices some sellers feel you should pay for it—just say NO to price gouging! Note: These nozzles are kept in position with stainless steel socket-head screws. Do not use mild steel screws; they will oxidize in place after a few heats. It takes months to wear out a flame retention nozzle, but they are disposable parts, and frozen screws must be drilled out. The outer tube should be 1.125” longer than the distance of its inside diameter. The spacer ring should be 1” long. The nozzle is kept in position on the burner’s mixing tube with as little as a single screw, or as many as six screws, depending on how well it fits up to the mixing tube. Caution: Stainless steel flame retention nozzles on a good burner design, will get to yellow heat in ambient air, if you burn propylene, and will quickly melt down in a forge. The same nozzle will get to orange heat in ambient air, burning propane, and will melt down in a forge, if they are not recessed back at least one-inch into the burner portal; do not position them close to the forge’s swirling super-heated atmosphere!

5/16”-3/16” and 8x5mm tubing can both be used to create gas tubes, which are screwed directly into (drill press drilled) ¼” thick aluminum mounting plates, and then locked in position with a flange nut. If you chose a nylon inserted locknut for this, it will stay in the correct position, without need for brazing, soldering, or gluing it on the gas tube, after the optimal distance between gas orifice and mixing tube opening is found (during tuning).

If you managed to get the regulator up to twenty PSI, it has no built-in flow limiter. That is good. A series of holes as air ducts is your next problem. Move the choke out of the way, and see if there are any holes in line. If you find some, than cutting between them to create air slots should improve burner performance. Finally, the tip of the gas tube's orifice should be between 3/8" and 1/4" away from the forward end of a burner's air openings, if your burner has a movable gas tube. However, if your two burners are 3/4" size, I would advise simply replacing them with Mister Volcano burners ($25 each and worth every penny).

Size comparison of parts in the photo isn't a good way to judge burner size. All of the Hybrid burners were built with mild steel schedule #40 pipe. Below is a list of pipe sizes used for minxing tubes. Compare your burner's mixing tube with it, to see what size burner you have. A 3/4" propane burner is considered large enough to properly heat 350 cubic inches of forge interior. For every pipe size large, double the number of cubic inches. For every pipe size smaller halve the number of inches. However, it is good to remember that these burners have tremendous turn-down ranges. If your burner is too large, just reduce gas pressre until you are satisfied with the result (A) 1/8” pipe is 0.405” O.D. x 0.270” I.D. (B) 1/4” pipe is 0.540” O.D. x 0.364” I.D. (C) 3/8” pipe is 0.675” O.D. x 0.493” I.D. (D) 1/2” pipe is 0.840” O.D. x 0.622” I.D. 1 (E) 3/4” pipe is 1.050” O.D. x 0.824” I.D. (F) 1” pipe is 1.315” O.D. x 1.049” I.D. (G) 1-1/4” pipe is 1.66” O.D. x 1.38” I.D.

I'm sorry to say that you won't like anything I point out. First of all, this is an also ran no name brand. I looked up this forge on the Net, and found that the photos are photo-shopped. The tool that they featured in them is for casting--not forging. Everything about it is super cheap; that includes the regulator, which is likely meant for a barbecue grill, which means that it has a built-in flow limiter. Is there any way that you can send it back and buy a Mister Volcano? Otherwise, you and we will will need to go through everything about it, just to get it running.

5/16”x 3/16” brass tube is 0.3125” outside diameter by 0.1875” inside diameter. 8-millimeter tubing is 0.312” outside diameter. 5-millimeter inside diameter is 0.195”. So, both 8x5mm and 5/16”x 3/16” brass tubing can be threaded for either MIG contact tips, or 3D printer nozzles. Both 5/16-18 and 8mm rivet nuts and flange nuts.

Stainless steel braided propane hose is sold in various lengths, up to sixteen feet. The longer this item has remained on the market the more its price has fallen; it can now be purchased for about the same price as twin torch hose. This armored hose is not quite as flexible as twin torch hose for use with hand held burners, but is a superior alternative for equipment use. Nearly all of these hoses come with standard (for propane equipment) 3/8” flare fittings; usually female at both ends, but some have a male fitting on one end. It is wise to buy your hose from a local supplier, rather than on line. It is even wiser to avoid Amazon ‘deals’ on hose and regulator combinations; most of those regulators have built in limiters, to reduce gas flow to barbecue volumes.

You are correct to aim the burner to create swirl. However, you need to place it at the top, both to reduce stress on the brick wall, and to aim the the flame so that it can impinge on a hard half-brick, or high alumina kiln shelf (better) floor.

you're welcome, NicZa. Tim, You made good points, but he needs to consider all sides of the of the picture, when it comes to running that burner without its flame retention nozzle. Yes nozzles are not required if a burner is mounted in a forge, but losing it changes flame shape. Properly tuned Hybrid burners have long sharp flames; they will become shorter and bushier without the nozzle, which can be good or bad, depending. There is no such thing as a free lunch with burner design. Sans nozzle, the wear and tear, which the nozzle is meant to take (as a replaceable part), will simply get transferred to the brick wall.

"Soft firebricks" is a relative term nowadays; yours are rated at 3000 F. With the coating you plan to add, they should last very well. Such description as you gave regarding your mystery burner, narrows it down to probably being a Hybrid burner, which were built in the U.S.A. and all featured blue choke plates; this is a good design, although the company is out of business now.

Important retraction! The instructions I wrote about using 6x4mm bras tubing as burner gas tubes for 3D printer nozzles will not work. You must employ 6.5mm tubing. Yes, I did do the work before writing the original instructions up, but did not realize that the M6 tap I purchased on Amazon.com was switched out with an M5 tap. By the time an M6 tap is run in the tube, no room will remain for external thread. My sincere apologies.