Mikey98118

there has been a fair amount written on burner blocks in the various threads available here, and there has been a fair amount written on burner ribbons here and elsewhere. Both devices have something in common; they both become super-heated flame nozzles; hint, hint...

Frosty, Agreed burners in the form of multi-holed gas manifolds have been around forever; I'm specifically after the refractory forms, including where and when cast high alumina, gave way to hardier refractory formulas.

Burner blocks are especially useful in brick pile forges, but homemade multi-layered burner blocks are a valuable addition to any burner design. Most burners have large secondary flames, partly because they are not designed to feed a gas/air mixture at sufficient speed to operate well with a tube and spacer type flame nozzle, and therefore the flame isn’t exposed to a double ignition source. But, refractory flame nozzles can be heated well past temperatures that would melt a stainless steel nozzle without even sagging out of shape, and unlike metal flame nozzles that must be sheltered from full furnace heat, will become just as hot as the equipment interior, inevitably producing superior combustion; they will stand up to very high temperatures, allowing hotter fuels, and/or oxygen enrichment to become practical choices in heating equipment. Still, building and using a burner block has its own problems, which can be reduced by employing carbide encrusted hole saws to drill through squares of high alumina kiln shelves (these are very resistant to shock from rapid thermal cycling and direct flame impingement), which can then be stacked to reach the desired depth for use as a flame nozzle, with the first layer cut the width and length of a brick, to act as the hot-face; these parts can then be aligned in a wooden form, with castable refractory of your choice added to form a standard brick, or any other desired shape.

clenceo, I would recommend a burner block instead, on that forge. Burner blocks are especially useful in brick pile forges, but homemade multi-layered burner blocks are a valuable addition to any burner design. Most burners have large secondary flames, partly because they are not designed to feed a gas/air mixture at sufficient speed to operate well with a tube and spacer type flame nozzle, and therefore the flame isn’t exposed to a double ignition source. But, refractory flame nozzles can be heated well past temperatures that would melt a stainless steel nozzle without even sagging out of shape, and unlike metal flame nozzles that must be sheltered from full furnace heat, will become just as hot as the equipment interior, inevitably producing superior combustion; they will stand up to very high temperatures, allowing hotter fuels, and/or oxygen enrichment to become practical choices in heating equipment. Still, building and using a burner block has its own problems, which can be reduced by employing carbide encrusted hole saws to drill through squares of high alumina kiln shelves (these are very resistant to shock from rapid thermal cycling and direct flame impingement), which can then be stacked to reach the desired depth for use as a flame nozzle, with the first layer cut the width and length of a brick, to act as the hot-face; these parts can then be aligned in a wooden form, with the castable refractory of your choice added to form a standard brick, or any other desired shape.

The published book has lots of USEFUL technical information, but not on this subject. Probably the most valuable information in it was on equipment building, although people usually buy it for the burner write-ups. Outside of the multi-hole, which caused a sensation for the first couple of years, I've heard little on the other equipment, directly; although the forge has appeared in various altered versions on youtube. You need to remember it's been published for nearly twelve years, and we've all moved on, yes?

Frosty, I think that's a good idea; a curved one could be shaped from Kast-O-lite 3000; I don't think it would need to be all that large. Or high alumina kiln shelf could be cut and mortared together as a flame impingement shield; either would allow the burner flame to be pointed upward for greater swirl and greatly reduced scaling. kiln shelving could be cut into any convenient shape, with narrowed arms penetrating the steel end pieces, to hold the wider impingement shields centered on the flame or flames like targets, positioned say 1/2" between them and the finish coated ceramic fiber.

As to the other question, local potters' supply stores usually sell ceramic fiber blanket, as do boiler shop and HVAC suppliers, and some stove supplies companies. If you can't find what you need locally, or can't find it in small enough amounts, Wayne.co will help you. McGuills Warehouse is usually the cheapest online source for full roles, but they are located in Southern California. Since distance affects shipping costs, how far you live from them versus some other source also comes into play.

The way a high-emissive coating works, is that it absorbs heat so easily that it quickly becomes incandescent. Think of a thin layer of zirconium oxide molecules exposed to a high heat source, and radiating that energy in all directions; now picture another layer of molecules next to the first, with still other layers behind them. Each layer radiates heat in all directions, but the heat source only comes from one direction, so at every additional layer some heat gets subtracted as it is radiated back toward the coating surface. Thus a thin coat is transferring lots of energy through a crucible wall, while the portion of heat it radiates back into the equipment is then re-radiated back at it, while the thicker coating on equipment surfaces reduces heat transfer that would otherwise happen through conduction by radiating a higher percentage of it back into the equipment interior. So, high-emissive coatings are a simple but elegant form of recuperative energy generation.

On the other hand, is 67% heat reflection such a poor showing? YES it is, which is why products like Plistex can legally claim to be "almost as good as ITC-100," but the truth is that what's legally claimed and what's true don't match up. You see high alumina products are such poor heat conductors that they are rated at 70% heat reflection. However the 67% reflection of crude zirconia particulates has to be averaged out with the "up to" 90% heat reflection of the fine particles. Still when one company plays loose with the facts, it can hardly complain when its competition "puts the shoe on the other foot"

So, getting back to ITC-100; what is the secret ingredient? Officially, I don't know. But government sponsored experiments with zirconia coatings back in the sixties tried a number binders; the most successful was orthophosphoric acid (commonly called phosphoric acid); a readily available and inexpensive substance that stays suspended in water, and has some interesting physical attributes. When painted unto a surface it is adhesive, and will hold zirconia particles suspended on that surface. When heated, it polymerizes as the acid forms esters. Thereafter it remains on the surface in a vitreous form at normal temperatures, and becomes adhesive above 365 F from then on. Does this remind users of ITC-100 of anything? Well, there are your options, and every one of them is better than using the ITC product, yes?

Jeff, Jeff, I can see that you're into taking responsibility for understanding and using "raw" materials, so yes, there are a number of choices that beat the heck out of ITC-100; not only costing less money, but giving better performance at the same time. And since a so called IR reflector (actually a high emissivity coating) will be of especial help in your situation, let's lay them out. In the first place, ITC-100 claims "up to" 90% IR reflection. And, you guessed it; "up to" is actually a cover for the nasty truth that their formula can also mean "low as" 67% reflection; its all a matter of particle size. Being a naturally suspicious cynic, I tried separating the colloidal content from cruder particulates in their product by spooning some of it into a glass of water and presto; the crude stuff fell out of suspension and immediately sank to the bottom of the glass. So, I mixed in as much as I could, and painted the much thinner coating over an already ITC-100 coated surface. My forge went from bright orange to yellow-white incandescence with the same burner and regulator setting. Point proved. When ITC products first came on the market, stabilized zirconia cost twice as much as the regular kind. Today, there are three different ways to stabilize zirconia, and the price has fallen to about one-third more than the regular stuff; this is an important factor to keep in mind. So, if the colloidal stuff is so much more effective why have crude particulates in the content? MONEY; what is commonly called zirconia "flower" is nearly 100% colloidal, and will give you the full emissivity benefit; but it's not cheap. Why, did you know that a 500 gram bottle of this stuff will cost a full third of the price you are paying for ITC-100?!? But, wait, the ITC product has water content, and a SECRET INGREDIANT!!! Obviously, you can't get along without their miracal product...or can you? Zirconia changes its crystalline structure at about 900 F, from square to hexagonal and then back to square again during cooling, so twice a heating cycle, it also changes particulate size, which is very hard indeed on every other ingredient in a rigid refractory coating; as in turning them to dust; and so manufacturers of high heat crucibles (and others who's products justify the added expense) employ stabilized zirconia. A product that became popular while waiting for reasonable stabilized zirconia prices to happen is zirconium silicate; since this has silicate and zirconium mixed in a crystalline structure, it makes an end run around the problem, and is reasonably priced. You can buy zirconium silicate already mixed with a binding agents (Zircopax?) Both zirconia and silicate are very resistant to flame erosion, and chemical attack, and are generally tough ingredients for a hot-face coating. however zirconium silicate separates out into its two constituents over time at high heat, and it is only about 67% IR reflective. So, if you want maximum protection for your hot-face layer, stabilized zirconia mixed with a good refractory binding agent (ex. calcium aluminate) is the optimal path. To continue, the concept of high-emissivity coatings rather than using the technical shorthand phrase "IR reflector": Yes, there actually are substances that reflect infrared energy; the most notable being gold, followed by silver and aluminum. But the difference between cause and effect is important. Actual IR reflectors are only useful as ultra thin coatings on optical devices, such as light filters in welding helmets. High-emissivity coatings can be used to more effectively transfer heat through a crucible wall (as a thin coating), or bounce deflect energy and also insulate surfaces against heat gain in thicker coatings; to illustrate the importance of the point, we will define thin zirconia coatings as one millimeter (just under .040") and thick coatings as three to five millimeters and up. And the higher the heat level the more effective high-emissive coatings become, while every other form of insulation loses efficiency as heat levels rise. And the thicker the coating the greater the insulation becomes. Induction "furnaces" for instance, use crucibles made of zirconia refractory, which is transparent to EMP waves, but is so efficient as a high heat insulator that with secondary insulating refractory between the coils and an inch or less of it beyound the coils, becomes the furnace as well as crucible.

Sorry DSW, Those two postings where meant for another thread. What you are describing is almost certain to be ITC-100

To continue, the concept of high-emissivity coatings rather than using the technical shorthand phrase "IR reflector": Yes, there actually are substances that reflect infrared energy; the most notable being gold, followed by silver and aluminum. But the difference between cause and effect is important. Actual IR reflectors are only useful as ultra thin coatings on optical devices, such as light filters in welding helmets. High-emissivity coatings can be used to more effectively transfer heat through a crucible wall (as a thin coating), or bounce deflect energy and also insulate surfaces against heat gain in thicker coatings; to illustrate the importance of the point, we will define thin zirconia coatings as one millimeter (just under .040") and thick coatings as three to five millimeters and up. And the higher the heat level the more effective high-emissive coatings become, while every other form of insulation loses efficiency as heat levels rise. And the thicker the coating the greater the insulation becomes. Induction "furnaces" for instance, use crucibles made of zirconia refractory, which is transparent to EMP waves, but is so efficient as a high heat insulator that with secondary insulating refractory between the coils and an inch or less of it beyound the coils, becomes the furnace as well as crucible.

Jeff, I can see that you're into taking responsibility for understanding and using "raw" materials, so yes, there are a number of choices that beat the heck out of ITC-100; not only costing less money, but giving better performance at the same time. And since a so called IR reflector (actually a high emissivity coating) will be of especial help in your situation, let's lay them out. In the first place, ITC-100 claims "up to" 90% IR reflection. And, you guessed it; "up to" is actually a cover for the nasty truth that their formula can also mean "low as" 67% reflection; its all a matter of particle size. Being a naturally suspicious cynic, I tried separating the colloidal content from cruder particulates in their product by spooning some of it into a glass of water and presto; the crude stuff fell out of suspension and immediately sank to the bottom of the glass. So, I mixed in as much as I could, and painted the much thinner coating over an already ITC-100 coated surface. My forge went from bright orange to yellow-white incandescence with the same burner and regulator setting. Point proved. When ITC products first came on the market, stabilized zirconia cost twice as much as the regular kind. Today, there are three different ways to stabilize zirconia, and the price has fallen to about one-third more than the regular stuff; this is an important factor to keep in mind. So, if the colloidal stuff is so much more effective why have crude particulates in the content? MONEY; what is commonly called zirconia "flower" is nearly 100% colloidal, and will give you the full emissivity benefit; but it's not cheap. Why, did you know that a 500 gram bottle of this stuff will cost a full third of the price you are paying for ITC-100?!? But, wait, the ITC product has water content, and a SECRET ADHERENCE INGREDIENT!!! Obviously, you can't get along without their product...or can you? Zirconia changes its crystalline structure at about 900 F, from square to hexagonal and then back to square again during cooling, so twice a heating cycle, it also changes particulate size, which is very hard indeed on every other ingredient in a rigid refractory coating; as in turning them to dust; and so manufacturers of high heat crucibles (and others who's products justify the added expense) employ stabilized zirconia. A product that became popular while waiting for reasonable stabilized zirconia prices to happen is zirconium silicate; since this has silicate and zirconium mixed in a crystalline structure, it makes an end run around the problem, and is reasonably priced. You can buy zirconium silicate already mixed with a binding agents (Zircopax?) Both zirconia and silicate are very resistant to flame erosion, and chemical attack, and are generally tough ingredients for a hot-face coating. however zirconium silicate separates out into its two constituents over time at high heat, and it is only about 67% IR reflective. So, if you want maximum protection for your hot-face layer, stabilized zirconia mixed with a good refractory binding agent (ex. calcium aluminate) is the optimal path.

Certainly, if you want to insert a metal tube, I wouldn't discourage it, but if that part gets hot enough to melt plastic, despite being cooled by the incoming propane, than you have a lot bigger problems to deal with!

Too soon we gets old; too late we gets smart. Better late than never.

I'm sure you're quite right about them, and furthermore, I'll bet a certain amount of repair work will have to be done on their burners too; their products are cheap at a cheap price; anyone expecting more than this is living in a dream world. On the other hand people can buy American at full price and still end up with unsatisfactory equipment; Ive heard a lot of grumbling about that from people who hate their high priced unsatisfactory forges... Or people can buy one of the few satisfactory forges on the market for quite a lot of money (try Chili Forge), build several forges spending a lot of time and a lot of money because "they new better than the experts," or obtain a book, actually read it carefully, and follow its instructions EXACTLY (this is the least traveled path). Ain't life a bitch?

Frosty is right. I'm saying stick the barbed ending of your burner into an American hose, and screw the other hose end onto an American regulator.

Jeff, I like the choice of a stainless steel trash can for the shell; that was clever. His choice of homemade refractory and finish coat was clever too, and I wish it would work, which it will for a very short while, and then it will fall apart. Sodium silicate fails around 1900 F, and that is what is holding everything else together. Perlite also fails at about 1900 F; together sodium silicate and Perlite make a very good outer layer, IF they are protected by an IR reflective coated castable refractory hot-face (inner layer), which is then surrounded by a thick secondary layer of insulating refractory, such as ceramic fiber.

JHCC, This is totally off topic, but with hands like that you might consider coaxing her to take piano lessons; talk about a reach!

BTW, charles, One of my favorite contributors on a casting group is into jewelry work and uses his jewelers torch to power a miniature casting furnace. I'm trying to provoke him into countering my argument, because this is an issue I'd rather lose than win--so long as it can be done safely

Light Hammer, Adjusting the flame nozzle position affects the flame; making it harder and softer; the more overhang the softer and visa versa. A tapered nozzle's position will affect the flame much less than a straight nozzle with spacer ring, BUT, not every burner develops sufficient mixture speed to support this second nozzle design. Therefore, first see if you can get the result you seek with the tapered nozzle. Your reducer is sufficiently large, but you would also need a MIG tip in your gas pipe; not a side hole. to support the nozzle. As has been stated elsewhere, the minimum performance you need is a neutral flame, which is recognized primarily by flame color; a light blue flame without the slightest tinge of green in it. You can self-teach what that means by using your choke while watching the flame. After you get that done, your next goal is to see how much you can reduce the secondary flame envelope; 'nough said for now.

Mister Tim, the other end of the hose still has a fitting on it, and can screw onto a regulator.

Ianinsa and Frosty both have it right. A flame nozzle on that burner would probably lengthen your flame, and in this case you don't want to go there.

Probably the best all round position is from the bottom facing up, so far as overall efficiency is concerned. But, the most popular position is about twenty degrees off top dead center. As with so many things, it's not just about efficiency, but more about personal preference. I would recommend that newbies use a loose kiln shelf or firebrick and play with burner positioning by trapping tunnel forges between angle irons before deciding how to aim their burners. A little extra effort to make the right-for-you decision is always a good investment.