Mikey98118

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About Mikey98118

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  1. Mikey98118

    Open air burners vs gas forge burners

    Also, switching to a hotter fuel (like propylene) could make a large enough air-fuel burner a practical alternative to oxy-fuel torches. Hotter fuels combined with better air-fuel burners good for silver brazing of large objects. The English have used chip forges to heat work from below while air-fuel burners provide extra heat to bring up small target areas at a time on large work pieces.
  2. Mikey98118

    Open air burners vs gas forge burners

    Some requirements change and others don't. since heat dissipation is the central problem, a coal forge would seem to be one answer. Rapid heating with oxy-fuel torches is another way to go for shop work on odd jobs. Even partial containment of exhaust gases greatly reduce fuel use, so cast refractory or refractory brick tables and partial walls (backboards) to retain some flame heat are called for. If the job is big enough to justify the expense, ceramic wool blanket can be use as a backing board, and discarded afterward.
  3. Mikey98118

    Need to know best U.S made propane forge companies

    Glenn gave you good advice. I will go further and suggest that you will probably end up buying and/or building two or three gas forges, for several reasons. Gas forges are sized and shaped to get the most from your fuel use versus the maximum choices of what they can be used to heat. Everything about gas forges are trade offs between competing factors. The one sure bet about them is that the more you learn before you buy or build the more you'll gain for your investment, whether its time or money.
  4. Mikey98118

    New forge build coming together

    I believe it was Frosty who first named them "tertiary"; what are they? They are a third flame envelope. Tertiary flames are purple, large, and ghostly; sometimes you have to look hard to see them in flame photos; They are a third flame envelope; always the outer envelope when they are present at all. Sometimes a beginner will only see two flame envelopes and say aha! How can a secondary flame envelope possibly be called tertiary?!? It can't, but the answer is that you have failed to detect the two flames inside the 'first' envelope. Sometimes people will see a white flame with a blue envelope around it and think it is a single primary flame. Wrong; the white flame is the primary flame and is surrounded by the blue secondary flame. Sometimes a lighter blue or blue-green flame will have a thin darker blue "edge" surrounding it. Once again you are seeing both primary and secondary flames. Sometimes blue-green or lighter blue flame will be interspersed with darker blue flames in a patchwork quilt of primary and secondary flames. What all these flames will ALWAYS have in common is a tertiary flame envelope surrounding them, and pushing out ahead of them; it may be strong and large, or faint and small in comparison with the other two envelopes, but it will be there. What then is the tertiary flame? It is escaped superheated oxygen and carbon monoxide molecules that are either combining with secondary air in the forge or else being expended out an exhaust opening.
  5. Mikey98118

    New forge build coming together

    A bigger inlet bell will help induce more atmosphere, and so it is conceivable, but not very likely, for this improvement to help contribute to scaling, but only if other things on your burner are way out of whack. Why? Because a larger bell only makes it easier for the gas jet to induce air into the burner opening; it is a passive factor; not an active one. A rich or lean flame while usually result from the diameter or the gas jet's orifice being to small or large in comparison with the burner's mixing tube diameter. As a bell reducer or cone shaped air inlet's large opening increases size in proportion to a given mixing tube diameter, the strength of the vortex it creates also increases. The resulting advantages of vortical flow that then increases with it is what make a large bell reducer such a major advantage on linear burners; it isn't a question of gathering air from a larger area--that is irrelevant.
  6. Mikey98118

    New forge build coming together

    A flame is a chemical reaction between oxidizer (in this case about 20% of the atmosphere) and a fuel source (propane in most gas forges). Heat and secondary gases (byproducts of combustion in the primary flame) are the ORIGINAL results. If the primary flame envelope doesn't perfectly combine fuel and oxidizer one of the gas molecules blown forward within your forge ( usually straight toward your superheating work pieces) is superheated oxygen. Note the stress placed on super heated work surfaces and also superheated oxygen molecules; that's because heating these two factors increases chemical combination of them into scale (oxides of iron). giving a few extra inches for escaped oxygen to combine with secondary gas from incomplete combustion (carbon monoxide) reduces the amount of superheated oxygen that impinges on work surfaces. Of course the presence of more carbon monoxide in fuel rich flames also help "scavenge" oxygen from exhaust gases before it can reach your work; the question of how much is just right, or is too much is an ongoing debate... You are correct that an oxidizing flame will contribute heavily to scaling, but we are talking about the same result, scaling, from two very different problems
  7. Mikey98118

    Forges 101

    I also recommend rigidizing and curing the ceramic fiber before applying the refractory layer; can you skip doing this step? Yes, but why would you? I believe in setting up a job as well as possible, to ensure good results.
  8. Mikey98118

    Freon tank for Farrier style forge

    Controversy aside, that question needs an answer. As to tilting a burner SOMEWHAT backward in a horizontal forge; it could increase hangtime if there is no opening at that end; otherwise probably not. Many forges do have a small opening at there back (with or without a closable door would also affect whether a backward tilting burner is a positive or negative move. In case of an opening at the rear of the forge, moving the burner's position more toward the forge's rear, and tilting it slightly forward would be the safer bet. A few years ago I did propose tilting a burner somewhat downward in vertical casting furnaces in order to increase hangtime, but in that case the safety drainage holes in their bottoms were covered with crucibles during normal operation, so they presented no problem.
  9. Mikey98118

    Freon tank for Farrier style forge

    I built mine to raise and lower on a seesaw arraignment, with an adjustable weight; you don't need a lot of positive closing force. I prefer gravity over springs; it never gets worn out
  10. Mikey98118

    New forge build coming together

    You still seem to be getting a large tertiary flame, which I believe is going to give you a lot of scaling. How much is good enough in a flame is a personal decision, but when, and if, you get tired of the scale problem you will be right back to fiddling with your burner. I don't beleve you are that for from success on that score; a longer jet or a larger reducer and you would be there.
  11. Mikey98118

    Freon tank for Farrier style forge

    No; you don't want to clamp or lock the forge parts in position. Heated parts need room to expand, or they will crumble.
  12. Mikey98118

    Freon tank for Farrier style forge

    You're welcome. The one thing you want to take the time to get right is cutting and filling the upper and lower parts to ensure they meet without gapes. Take the extra time to cut cleanly; if you mess this up, then take more time to grind the edges smooth. When you cast the refractory into the two shells make sure they are laying horizontally. Use a wooden form to raise the refractory slightly higher than the shell edges. When the refractory is set firm, but before it gets hard, run a straight edge over the refractory edge to cut it back even as possible against the edge, but making sure it ends up forming a flat pane whether the shell edge has one or not. This way you have several opportunities to get the job done right; this allows you to do without employing ceramic rope to keep the forge from having exhaust leaks, which are quite irritating to live with
  13. Mikey98118

    Freon tank for Farrier style forge

    Yes, many people who have multiple burner forges cut bricks or broken kiln shelve parts to make internal movable baffle walls, in order to isolate part of a large forge to a single burner when possible, and save big bucks on fuel costs. Also multiple burners can be turned down, so that large areas can be heated without overloading their exhaust openings---your have a solid point there. The idea, which has been around for years, is that two or more smaller forges can be lined up with a small space between them to allow one end of each forge to share exhaust space, keeping the burners flow from being choked back from too much exhausted gas in an available opening, while keeping the heat available between the forges from dropping off to much. We had a guy on here (last year?) who built a beautiful oval mini-forge by cutting a car muffles in half, which leaves the other half of the muffler available to construct a second forge. Mounting two smaller burners (rather than single larger burner) in the forges would help to keep a more even temperature in the whole assembly. BUT, for your purposes, I would recommend a clam shell forge; note that this is a forge that has top and bottom halves. Clam shell forges can open on a hinged top side, or can be raised up and down on tube within tube rails; whichever is most convenient to the build. What clamshell forge don't need to be, is any particular shape, round, square, rectangular, as you find convenient.
  14. Mikey98118

    Burners 101

    Lifting Fame is "beautifully descriptive" and is now part of my vocabulary too; it is nice to now its an "official" description, but it would have gone viral on this group regardless; it's just too handy not to Well, that is about reducing drag made by a fluid passing over a rounded edge; how a square passage. like in a 1" square tube would affect a fluid passing along it isn't down to me. I do know of a commercial forge builder who featured burners constructed of square tubing; he claimed they were superior, but never provided a flame photo... Since I recently started working with linear burners again, I have noticed that they are far more forgiving and easy to get along with than jet-ejectors. For years I took it as an article of faith that they just weren't as powerful as jet-ejectors, but I begin to wonder if their problem all along has been that they are too forgiving, thus allowing people to settle for building "just good enough" burners, instead of pushing for darn good burners. It was said back in the sixties that the big difference between an old Ford and an old Chrysler was that the Ford would run without much tuning but the Chrysler had to be tuned just right to run; so old Chryslers ran like tops, and old Fords--not so much.
  15. Mikey98118

    Forges 101

    Exhaust openings As in so many other matters, NO exhaust size or shape is ever perfect. Therefore V-A-RI-A-B-L-E becomes the optimum; all other dimensions can be outright wrong, but never just right. This is one of the many reasons for controlling exhaust with an external baffle wall beyond a larger than otherwise needed shell opening; thus allowing the least heat loss through radiation, while maintaining perfect backpressure in the forge. One thing backyard casters and blacksmiths both worry over is how large to make the exhaust openings on their equipment. Too small and you have high back pressure killing burner performance; too large and you can't get enough heat to stay in the equipment interior to do your work. Of course, the closer to the "right" opening size your equipment has the stronger the forge or furnace can be built. Just don't get suckered into confusing the right size for the perfect size. As long as burner output can by varied (turn-down range), there can't be any such thing as a perfect exhaust opening size. The right size is what is needed to accommodate the burner's highest output (the highest you are willing to take it to). If you want best performance at lower gas pressures, they can easily be provided by an exhaust opening that is a baffle wall. How to do this, unless you already have a r-e-l-i-a-b-l-e figure to start from? You need to make up something with an exhaust hole in it that can be varied in shape size; like hard firebrick, or with several round kiln shelves with a variety of openings to fit stock through. Even should you get the best possible performance from your burner with a given exhaust opening, you are likely to be fighting very poor fuel economy. Try separating exhaust losses from radiant heat losses by putting up a movable barrier of brick, or a changeable high alumina kiln shelf with a small center opening for your stock. Keep the bricks or shelf at a small distance from the opening, to allow exhaust gases to move up and out, just between the exhaust opening and the baffle wall, while bouncing radiation off of a re-emissive (heat reflective) coating, and back into your forge. You can move a hinged and latched door holding containing a baffle wall, which can be moved closer and farther away from the forge opening, depending on how forcefully you are running the burner, while keeping the stock opening only as large as is needed to move parts through. This arrangement helps to slow the flow of expended gas in the forge interior, as it heads toward the exhaust opening; and then speeds the gas up through the opening; another highly desirable trade off, but how exactly is this trick done? As the gas exits through the restricted area of the exhaust opening, its flow speeds up due to buoyancy, much as a river's water speeds up as it approaches the falls. But isn't any opening subject to buoyancy? Yes, but the less its restriction to flow the less flow speed is slowed down in the forge interior, and the less it is sped up at the exit. So, you are gaining hang time for the heated gas in the forge, and recuperative savings from bounce back of radiant energy; a win-win situation; it also minimalizes infrared and visible light from impacting your eyes and skin. Both factors improve your health and comfort. Is there any improvement to be made over firebrick as a “baffle wall? Yes, but only after you use the forge enough to know what size and shape opening you normally favor: even then you may want to keep the brick on hand for occasional use with unusual parts. For the long haul, high alumina kiln shelves are seven times more insulating than hard fire brick; it is also tougher at forge temperatures, which is an important consideration for something you will end up shoving parts back and forth through. Using alternate kiln shelves, with different part openings is okay, but building an elaborate system of moving kiln shelf parts to ape the ability of bricks to change their openings with, comes under the heading of "gilding the Lilly." The additional energy savings it provides probably isn't worth the effort.