Mikey98118

1DaramG, Let's keep the confusion down by starting right where you are. I can't be sure without you providing a close-up of the head of your present torch, but you can probably get away with sheathing its end in a tight fitting stainless steel tube or pipe. This is what you need to make sure it survives being mounted within the forge's burner portal (the hole it is laying in at present). Properly mounting your present torch, or whatever torch or air/fuel burner you eventually choose, will increase internal temperature in that forge by about one-fifth. It looks like you employed castable refractory to line your torch with. I have made several forges and furnaces, with nothing more than hard castable refractory; it isn't the best choice, but is also far from the worst. You can work with it. What you need more than a change in liner is to finish the forge, by providing an external baffle wall of firebrick, about an inch in front of the exhaust opening. Most people choose insulating or semi-insulating firebrick, but even plain firebricks will do a marvelous job of increasing forge temperature. This movable wall allows the hot gases to exit, while bouncing radiant heat back into the forge. Next, you need to complete the refractory lining with a coat of re-missive material; there are several to choose from, but even plain kiln wash will do wonders. Why? Have you noted how rough the surfaces of your refractory is? All of the recommended coatings, including kiln wash, are SMOOTH. How well heat is reflected back from an incandescent surface depends on how small the particles that make up that surface is; this is why all these coatings rate their percentage of heat reflection as "up do." The whole point of a forge is control of the heat that a burner or torch provides, So: (A) Control the heat at its entrance (burner portal) by controlling the amount of secondary air that the flame can induce. (B) Control the heat loss through its wall, with a finish coating, so that the forge interior will super-heat, causing it to radiate more. The hotter the internal surfaces the higher the percentage of heat transferred into your work. At yellow incandescent far more of the heat transferred into your work is from radiant energy; not directly from the flame. (C) control heat loss through radiation at its exhaust, by bouncing that radiant energy back into the forge interior. You will find these little tricks doing as much for you as a better torch or burner

I cannot give very much advice on ribbon burners: fortunately, there are others here who can, and will jump on the chance to. Although they spend most short trips in Paris, Kathy and her BFF enjoy touring all of France, when they have time. Loved the photos.

So far, stepped flame retention nozzles do a much better job of controlling the flames of thigh speed air/fuel burners than tapered nozzles ever did.

Slide-over stepped flame retention nozzles 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, and tapping it into 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! Note: These nozzles are kept in position with stainless steel socket-head screws. Do not use mild steel screws; they will “freeze” in place after a few heats. Caution: Stainless steel flame retention nozzles on a good burner design, will get to yellow heat in ambient air, burning 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!

Hi Guillaume, Yes; the straight line of the "D" is at the forge's bottom. While my preference is for oval forges, I must confess that the "D" shape is way easier to construct, and "gives more bang for the buck." These forges also seem to be a natural fit with ribbon burners Tunnel forges are completely dated; they are the "well worn path," and as such they will continue for many years to come. But, eventually they will come to be laughed at; then, they will die out. Must pronouncements have exceptions, and mine is no different. Tunnel shaped forge/furnaces will stick around, and laugh back at the mockers Stainless steel is just a totally obvious choice; I notice ever more commercial builders are choosing it. I like that it is shiny, too. But where it stands out is twenty years down the road, when it still looks cool, and a mild steel forge is looking pretty beat up and burned out I know; the wife and her BFF keep getting on a plane and waiting for hours and hours to visit your country. Then. After a week they get on a plane, and wait for endless hours to come home; then wait for next year, to do it all over again! It's very strange; I think they need a hobby. They dragged me on a plane to do it once, and I discovered real french rolls...yum! People should Fly Air France whenever they can, is my advice. I don't like travel, but I totally liked Paris. Of course, it will ruin us for Yankee style (not so wonderful) Wonder bread...I better shut up, before I get the itch to travel again

I think the flame pattern has potential, but needs leaning out a little more. You seem to be on the right track...

No, it would not help at all. An important factor is how fast you use propane out of a given tank, versus the tank's size. Another factor is how cold ambient air surrounding the tank is, because it is heat from that air that is being transferred through the cylinder wall to raise the temperature of the liquid propane. Finally, as the tank becomes seriously depleted the amount of liquid propane that is contacting the cylinder wall becomes less and less; giving the same result as a shrinking cylinder would; less heat transfer from the ambient air.

Sodium silicate is a white powder that dissolves in water; it is usually sold in bottles, with the water already added; it is commonly used to glue Perlite together into a solid layer of secondary refractory insulation, as both products melt at about 1900 °F. Sodium silicate is also used to glue refractory fiber products unto other surfaces, like the inside of forge shells (containers). However, when used this way, ceramic blanket should be rigidized completely through all layers, to keep it from de-laminating, and falling away from the glued surface over time.

A good place to begin your search for an appropriate air/fuel commercial torch would be English manufacturers; they have been making air/fuel torches and burners for a very long time. Otherwise, you'd best figure on building a burner.

Understood, and agreed with

Except for those little twisters that you can create inside your burner

Yery good design work. However, you should consider a straight and parallel tunnel for your flame retention area. Otherwise, you are likely to end up getting back fires into the burner's mixing tube. Also, you would be better off raising the angle of the burner, and tunnel so that the flame is sure to miss impinging on the work, but more importantly to assure that there is no chimney effect after shutdown. Yes, a 1/2" should get this forge to welding heat. Yes, the exhaust opening's width is a plus, and I would suggest movable bricks for your baffle wall, rather than any forge door on this design. Thank you for posting such a fine drawing

Good point, and counterpoint. I always use needle valves on my high velocity burners; but is for fine control at my fingertips, rather than necessity. Regulators are all that is necessary; needle valves are just a luxury

And so we come back to the often disputed question of whether and how much altitude affects these burners. I think the ayes have it. But I also think it takes a lot more altitude than people worry about.

I agree with with this man's application being as safe an answer as there is likely to come along. I also agree that safety codes must be followed. However, I doubt that the code applies to this particular case, because the heat source is controlled. Furthermore, I paid for a copy of the code twenty years ago, and this subject was not mentioned in it then; I doubt that it is now.

By "trimming" did you mean "adjusting for" altitude? I'm not trying to be picky (this time :-). "T" burners are tuned by trimming back their MIG contact tip's lengths.

Or, they can stick with a plastic air chamber, and avoid some of those steps. If the burner is handled carefully, I don't see that as a problem. Not that some idiot won't make it a problem, sooner or later. The fans on my induced vortex burners, are also plastic, so I think about this stuff.

I recomend a MIG contact tip for 0.025 welding wire as the gas orifice in a Mikey 3/4" burner; that has an orifice diameter of 0.034". The amount of gas a burner puts out is controlled by the gas orifice diameter times the gas pressure. A Frosty "T" burners use a little larger orifice diameter and lower gas pressures.

They are supposed to restrict flow; that is the very idea. Understand that a 1/4" valve, ball or otherwise, produces WAY more flow than is needed. The final gas orifice sizes are given in thousandths of and inch!

h for anything smoldering in a corner or under a bench. Regulators and fuel hoses There is a lot to know about hoses, different kinds of valves, and other plumbing choices (black hose versus, copper tubing, versus stainless steel braided gas hose, etc.), but, so long as you think about safety FIRST, and avoid doing something thoughtless, all those choices are only about what I call "add-ons." Meaning they can be rearranged at your leisure, giving lots of time to learn the fine points about plumbing your equipment before making a final decision. For instance; should you install an idler circuit? That is best done with metal tubing or pipe--not rubber hose. I personally dislike using copper refrigeration tubing to plumb gas equipment; but there is nothing half as good to employ in an idler circuit. We must beware, not to trip over our “druthers.” The first piece of equipment attached to your fuel cylinder should be a variable pressure regulator. You cannot use acetylene regulators for any other fuel gas; they are illegal, unsafe, and impractical to use with LPG fuels. While you can use a typical multi-fuel gas industrial regulator, LPG regulators are less expensive and better suited for use with these fuels in cold weather. I recommend using a 0 to 30 PSI model, with a pressure gauge attached, although a 0-20 PSI regulator will serve just fine, most of the time. You can find good quality 0-30 PSI propane regulators offered on eBay, Amazon.com, or find them locally at large hardware stores. If you end up with a regulator that does not have a pressure gauge, or a side port in which to install one, you can add a “T” pipe fitting at the regulator’s outlet and install a pressure gauge there, using 1/4” short pipe nipples; one for the gauge and one for the gas hose. Caution: NEVER attempt to use water hose, or air hose, to carry fuel gas. Propane can partially dissolve the hose and/or seals on water and air fittings. The first you now of it, may be when the entire hose is suddenly ablaze (I was present when this happened to a friend). D. O. T cylinders are usually fitted to regular high-pressure black propane appliance hose; this is available with various fitting choices from hardware and appliance stores; I do not recommend it. Appliance hose is stiff (difficult to work with), overpriced, and seldom comes in twenty-foot lengths. Instead, I recommend using regular 1/4” size “T” (multiple fuel grade) twin torch hose in standard lengths. Once you buy the hose, remove the brass guards from both of its ends, and simply pull the red fuel hose away from the green oxygen hose (save that oxygen hose). What you end up with is a highly flexible top-grade fuel hose at a reasonable price, which can be found at any local welding supply store or ordered online. Take care not to end up with oxyacetylene torch hose; it must not be used with LPG fuels. Stainless-steel braided fuel hose is steadily decreasing in cost, making them a bargain priced safety item to add between the rest of your fuel hose and the last few feet near heating equipment; or for a few feet between an outdoor fuel cylinder, and a through the wall piping system (or indoor section of hose).

The 2-1/2 gallon "D" forge Another variant on two-gallon tunnel forges is a two and a half gallon forge, shaped like a “D” laying on its side; these are made from the top half of a five-gallon propane cylinder, cut lengthwise; this half has an exhaust opening cut into its front, is lined with refractory, and rests on a steel pan, which is filled with various refractory layers. Where and what kind of burner or burners will be mounted varies from builder to builder. A narrow ribbon burner can even be mounted in one side of the base pan, rather than burners in the half cylinder top portion of these forges.

Speaking of stuff. I figure you have more good ideas for stuff. We need to encourage you to cough up more of them wild thoughts floatin' 'round in your head

Another limitation in forge/furnace design is burner positioning. While the flame can be pointed in several ways in a forge, the flame in a casting furnace is aimed to impinge on the furnace wall as far forward as possible, without directly impinging on the crucible (since this promotes early crucible failure). If the flames in a forge were aimed this way, they would not burn for a long enough distance before impinging on work pieces, if the burner(s) should be pointed downward, toward the floor area. In these days of greatly improved refractories, it is better to aim them upward and slightly inward, to ensure the longest possible exhaust path in most forges; the exception being forges designed to create a hot spot, but there always are some limitations

I agree in principle. But, pushing the envelope is just sooo Mikey

Further details on C-c forges The main difference between a tube forge and a casting furnace is that the forge is positioned horizontally, and the furnace is vertical. With a little added work on its legs, and the addition of an emergency drain hole at the bottom to let liquid metal escape into a metal sand box (in case of crucible failure), a forge, with a locking hinged door, can be made to do both tasks well enough. One of the hard facts of equipment design is that there is no free lunch. Everything is a tradeoff. Being able to cast and forge in one piece of equipment must be paid for with some limitations on what can be done with the door and the floor, the larger the forge, the more serious these limitations become, but in a coffee-can forge/furnace the limitations are minor, because its capacity to heat work pieces for forging was minor to begin with.