Mikey98118

So, "Wikipedia gives adiabatic flame temperature as 1960 degC/3562 degF for Natural Gas and 1963 cegC/3565 degF for Methane vs 1980 degC/3596 degF for Propane huh"? With an oxygen fed flame maybe, but not with air. These figures are for an adiabatic flame, which is a concept use to help scientistsand engineers to play with formulas; not for builders to deal with equipment in the real world; slash those figures in half and it will actually work there. What is said to happen with methane combustion, is is a partial recombination of the combustion products, which cools down the flame quit a bit. Do i know that is the problem for sure? Nope; what I do no for sure is that methane is rated at about 1/2 the practical heat output of propane. I also know for sure that air methane burners are utterly puny.

Frosty, On the one hand I agree that for most smiths most of the time, good enough is good enough, so why should I consider it worth while to keep pushing the envelope this way? Nothing changes the same; especially not in the market place. A person can't do a thing about the price of fuel, rent, etc. But a person can always do better about fuel deficiency and how long the work takes to do. It was because of a bad local oxygen market that I stated getting interested in air fuel burners; that market never did improve, but what I could do without using oxygen sure did!

Brian, Back is 2004 my book was publish, showing people like you how to build very hot and very gas frugal burners, and just how to build the equipment to put it in; since then thousands have delighted customers all over the globe hav done just that. You don't even have to buy a copy, since it has been pirated on countless free sites. If you want an easy to build hot burner the Frosty "T" burner is available right here. There are various guys here who have built ribbon burners do, and Wane has a right up on it through his site. Are you saying you'd rather pine around for an author you can't contact than get all our help choosing a better burner in the first place? That isn't really what you're saying is it?

Frosty is dead on the money, I've gone way down the track with burners; into MIG tips' needles. and various other source of capillary tubes for making gas jets, and I couldn't answer a question into how to properly handle the gas jet on another man's burner design; every part is simply to enter related. You may as will be asking him to tell you how high is up.

I would not use natural gas as my first choice, but with a ribbon burner setup he should be able to chose back and for between it and propane anyway...

Robert, It's very simple. The reason this gas jet (which I called an "accelerator" in my book in order to make an important point) is there is to accelerate the gas molecules, exchanging the (worthless for our superposes) energy from pressure to kinetic energy in a high speed gas flow. If the gas tube was perfectly smooth there would still be friction; the friction of all those little molecules banging away on each other as they line up to do their jobs. The nigher the gas pressure the more the friction, and the smaller the tube the more the friction, too. It isn't that cross section of the gas tube doesn't matter, but it's not the big dog in the yard, now is it? Mikey

Help Frosty help!!! I here the guys talking about gas jet diameters and can plainly see they are confusing capillary tubes and holes; THEY AIN'T HOLES!! There is a little thing goes on in them called friction that changes everything about the process. I just can't get around all the words right now to pontificate on the subject, so you do it for me, please. BTW I'm back (kinda). Frankenburner

night66wolf, You are on an interesting thought track; this very subject has been discussed on other threads, with me egging others on to try such ideas. One guy used a funnel shaped opening to better direct his flame into a two-brick forge without overheating his torch. I also suggested trapping the torch in a short bit of pipe, with a variable opening to control secondary air induction. Nevertheless, advising you to build a small burner as the practical choice is only fair (the other guy was already using a torch for forge heating), You can get into a fair amount of trouble with such experiments, not least of which would be ruining your torch...

A typical forge built from a propane cylinder, which ends up with an 8" diameter interior will start out at bout 19" long and end up with a 16" to 17.5" long interior, depending of whether 2" ceramic blanket or or the much denser ceramic fiber board is used for end enclosures. Such a forge will mostly be heated to an even temp with a single 3/4" burner, with the last couple of inches at ether opening running somewhat cooler. For more even heating you would need two 1/2" burners placed at one-third, to one-third, to one-third distances apart. Compare this to the much longer and narrower forge you are contemplating, and maybe some more research?

http://www.joppaglass.com/burner/mini_square.html

Thomas, You are quite right, if the hose is left on the ground. I string mine out in the air on stands for off-site demos, and on the garage ceiling when in the garage. Another acceptable safety option is to build wooden protective ramps for use on job sites, within which the hose is protected even from vehicles running over them; these are not my techniques for protecting fuel hose, but are approved standard forms of protection on job sites. Is all this a pain in the six? Well, that depends on whether you're setting it up on a job site, or your arraignment is being inspected by the local fire department. Do I personally think a propane cylinder can be safely used under a forge cart, if all its connections are inspected and protected? So long as the law disagrees, and I write books on the subject, I decline to offer an opinion that some lawyer may quote in court, later on...

I'm just as interested in ribbon burners as others on this forum, but make no claim to expertise on this subject. However, J, Cornell recently brought up the subject, when he asked about the chances of making a naturally aspirated ribbon burner. After pointing out the claim made by knowledgeable builders that these burners not only had to be fan-blown, but that their fans must put out higher than normal pressure for these burners to "work," he directed my attention to the newest burner series featured on the Joppa Glass web sight. Joppa Glass features the equipment and knowledge of one of the most famous names in the Warm Glass movement; a man who pioneered many of the hot-work equipment building techniques we all use on today. Furthermore, his ribbon burner heads are fed from full venturi burners, which, as Frosty will tell you, drop input pressure to the flame nozzle even further than other NA burners. On the other hand the listed outputs on these burners make it plain that low pressure input to ribbon burner heads comes at a high price in lowered performance; there's no free lunch. So, why bring the subject up at all? The difference will matter to anyone building a miniature forge for knife making. More importantly, keeping our 'facts' straight is vital for anyone trying to design their own ribbon burner.

Apology accepted, Frosty. Thomas; I liked your point, not that I agree with it; don't find anything wrong with it, either. A definitive answer could only come through experiment. So, what I like about your point is that it ends up being food for thought on my end; never enjoyed ambivalence before, but it seems to make a great starting place for new insights, lately. On the other hand, this thread is getting worn out, and there are many other subjects to explore...I wouldn't mind getting back to ceramic nozzles, and ribbon burners just got a new twist from John. It seems JC read closely about Giberson's latest product, while I just looked and leaped past a mine of potential information on ribbon burners. The first conclusion, that they need to be fan-blown at all, has been blown away by Giberson's naturally aspirated full venturi ribbon burners (look this up on Joppa Glass website). A tentative alternative view might be that they put out about one-third the heat for the same size head, if they are not fan-blown. At any rate, this is a whole new aspect of ribbon burners. Shall we all saddle up and meet on one of the ribbon burner threads to kick this new information around? That way, we can surround him; he wasn't involved in this thread at all. I like to round up "all of the usual suspects."

Thomas, Good point. Frosty, I take it you're assuming I'm arguing with someone, rather than examining another possible use for temporary thermal loading? If so, I would begin my post with that someone's name, like I did this one. But if we are down to "low regard" I'll just let this thread end and go on thinking further on the subject privately.

Your torch is meant to attach directly to a propane or propylene canister, and run at full tank pressure, through a tiny gas orifice, which will rapidly plug up when exposed to the cruder product refillable propane cylinders dispense. Whatever else you do, this problem isn't going away. Your second problem is that the brass flame nozzle on your torch will simply melt when you place it within a forge, so the flame will have to remain outside the forge and shoot through a short air gap into a hole in the forge, losing between one-fifth and one-third of it effectiveness. Why don't you simply build a 1/2" Frosty "T" burner, as others on this forum have done.

So, if thermal mass is a great idea for heavy forge work, what about using temporary thermal mass to spiff up results in forges with underwhelming heat sources (ex. coffee-can forges being heated with a canister mounted propane or even butane torch), while the builder is trying to get a real burner constructed to replace such a temporary heat source?

Frosty, I have been frustrated by the quite disappearances of castable refractories that are use rated above 4000 F several times over the years, and am without a clue why this happens!!!

Ups! I forgot my old burners used a few threaded parts, and were built so that the gas jet could be aimed (which is how I got around that problem). for years I've replaced pipe with tubing, and updated all the other parts for better quality control (and better looks).

norrin__radd, Using wood forms, its easy to screw sheet metal onto them, forming any oval shape you wish; removing the screws to release the forms after brazing or welding stiffening faces at both ends to keep the oval shape rigid. The harder part is making decisions as to size, shape, and number of burners. You can do a lot to settle those questions in you mind by giving a close look to the various forges on the Chili Forge website. Please note that all those forges are meant to be high production models that are heated by oversize burners, and having very large openings; you might want to tone down that performance with smaller burners and openings. You would also need to decide on the approximate location for the burners in advance, so the the sheet metal can overlap in that area, providing more strength for mounting burner portals; and then run screws, etc. down the length of both edges. this in reply to your considering making much larger oval forges; not as a critique on your brilliant design for the miniature oval forge shown on this thread.

Forging Carver, I show a propane cylinder stored inside my forge cart, but it shares space down there with a twenty foot long red fuel line stripped from an oxy-fuel ("T" rated) torch hose. Even for people who mounted their fuel cylinders under their forges, this is a simple update to make. And, once again this isn't so much a safety issue as a legal one.

Thomas, Liquid fuel burners, especially gasoline and kerosene, are an interest of mine. I spent some time researching gasoline blow torches on the net, and purchased one of the the new Chinese steel head blow torches; will be experimenting with it this summer. Gasoline is a fuel rated at a little higher energy density than propane, yet the accepted figure for a gasoline flame is only 2000 F degrees, which is why I'm only beginning experiments with it. Personally I'm counting on figuring what exactly is wrong with these flames, and coming up with much higher heat figures, but tools are as tools do; if someone figures out the underlying problem great; if not, than it's just another dead end research project.

No dispute here. But what someone designs into a commercial product, and what it is safe and sane to recommend that newbies try are worlds apart. I built all kinds of little safety features into my early burner designs, and still got presented with changes that gave me the willies; all by people claiming to have built their burners "exactly per my instructions"

The only kind of glasses that will help, while leaving incandescent colors little altered are didymium safety glasses (spectacles are also available, and far more practical for hot work) Glassblowers use didymium to cut down on sodium glare, while still being able to judge color temperature as the glass cools; this will also cut down on furnace glare. What it won't do is reduce infrared, which is tiring for your eyes. Half a loaf is hardly worth the outrageous prices charged for these glassblowers aids, if you shop from the usual sources. Fortunately, Amazon.com sells all kinds of didymium glasses for reasonable prices.

With one, and only one, exception. preheated air must be introduced into a flame nozzle (usually ceramic) separate from the fuel, which means no mixing chamber other than the nozzle. The generally accepted central principle behind preheating the air is that, being about 80% nitrogen, a boost in flame temperature comes from the combustion process being saved the energy loss from heating all that useless nitrogen content. There are various other claims made for other preheat schemes, which are dear to the people pushing them, but which are just as enthusiastically disputed by others. Getting back to the single exception: There was an all stainless steel forge burner system developed at a national government laboratory, which preheats both fuel and air in its mixing chamber. Although there are accounts of this burner system's success, and no accounts disputing it, the inventor himself pointed out that the rather expensive tubing had to be replaced every few months, and that it had to be stainless steel; not such a good deal overall. Certainly, some warming of propane that is barely above freezing temperature in winter is worthwhile and safe. However, one of the reasons cold propane is my preference is the very convenient refrigeration effect, which I depend on for added safety in my burners, which set a little way inside of very hot equipment. Frosty likes to mount his burners on the outside of heating equipment and use an opening in the brick to form a flame nozzle; this scheme isn't going to need as much cooling of the burner, and so with his system you might push the warming a little more. Why warm the propane at all then? Because tiny pieces of frozen propane can be blown into the burner if it isn't kept warm enough to be pure gas; they disrupt the flame, and if ignored, could snuff it out. In my world safety is first, performance is second, and most other factors a distant third. Okay, frozen, is the wrong word; liquid is the right word.

Adam, Frosty is the expert on "T" burners, his fittings are different from yours, but he might approve of them anyway, after you answer a few questions, I think Frosty prefers to use Tweco tapered contact tips, the same as I do, but just how important tapering is with the "T" burner is not clear, because its burner's air openings funnel air into the burner beside and in front of the MIG tip, rather than from beside and behind it like my burners; the difference is how much air must pass by the MIG tip. At any rate, such tips are easily filed to a taper by spinning in a hand drill, under a file.