Mikey98118

1 hour ago, Frosty said:

It's so good to see news that makes you smile.

Last century, while still young, I noticed the trouble with parties, was all the people there, who were on the make, instead of having fun. That was the end of partying. Looking back, it is clear that fun is what you bring with you, or your basket never gets filled. Admitting the obvious has saved thousands of dollars and hundreds of hangovers

Yes, it surely is. I had no sense of humor, until recent years; everything is a trade off. Not with a bang, nor with a whimper, but with a sheepish little grin...

1 hour ago, Frosty said:

Okay, my memory isn't as bad as I was afraid! I was thinking we might've crossed paths on theforge.list, maybe.

We nearly did meet on that forum, but I was just getting acquainted with it, when you suffered your head injury. So, more time went by before we became acquainted on this one. Then came two strokes, and we are now well matched; all's well that ends well

19 hours ago, Frosty said:

I don't think we spoke directly until you joined Iforge. 

That's right, we first talked in 2014, here on IFI. It was another two years before I became a regular; after the home casting newsgroup I used to write on vanished, along with so many others.

It would be interesting to see if the $38 "T" burner works as well as expected. Of course, Frosty could easily bring it up to snuff, but it would be nice to know if it is already there, because that would make it a bargain for people who don't know the ins and outs of burners

Well, I started out with a similar oxy-fuel torch background, and had to update my early assumptions through the years. My views have often started out apposed to yours, only to be modified at times by your own.

Starting out with in the apposing camp, I paid critical attention to various photos of flames from "T" burners built by various people, including one that featured a "T" burner, with a flame retention nozzle burning out in the open air; it had what I considered a perfect  soft flame. I consider this to be no mean feat.

Mikey or Micky; it's all the same to me. Let confusion rain, if it will

What Florida Man gained for his $85 was a burner, gas hose, and adjustable pressure regulator. Conservatively figuring, only about $50 of this price was for a stainless steel burner of better than average design. So, this is actually a very good price for a gas burner.

You're right, that the light level makes looking for secondary and/or tertiary flames nearly impossible. However the primary flame looks good enough that I would not expect to see much secondary flame, anyway.

As to the burner assembly; you more than got your money's worth

Could the burner be improved? Yes; do you really need to? NO!

After the book was published, I got regular complaints on the casting group forum I visited that, "I built your burner just like you said, and it didn't work very well." I offered six times to fix their burners for free, if they sent them with return postage. Not one of them followed my instructions! So, when the seventh guy wrote the same complaint on my favorite forum, I changed the offer. I said he could have the same deal as the first six, but that I would describe every single thing he did wrong in loving detail on the forum, with photos, before I fixed his burner. He said no thanks. I got no more complaints after that

The problem is that everyone has a "better idea" then the path you lay out; this is just fine, if they "have a clue." Alas, that is a mighty big if.

I like innovation; where would we be without it? The problem is getting people to take a good look, before they jump into things.

I have seen lots of innovation from enthusiasts on this forum, and on previous forums (now defunct). One manufacturer from those other forums came up with oval forges, and began selling them over two decades back. The other manufacturer consulted me on forge burner design, and changed from selling fan-blown burners to Chili Forges present naturally aspirated tube burners. Both of their forge series cost several hundred dollars.

I don't think the band wagon jumpers do any deep thinking, before 'innovating.' It looks more like "well, this looks shiny; it'll sell real good." The only exception to this trend is Mister Volcano forges; it is actually worth more than the customer has to shell out for it.

Full size "commercial" forges have change very little in recent years. Chili Forge is the most recent design, and it is more than twenty years old. However, small economical gas forges now flood the market. Most of them are a mixed blessing. On the plus side, they can be easily improved, to become a worthwhile tool; this provides a third choice between building a gas forge from scratch, and paying several hundred dollars, just to find out if someone wants to forge steel.

On the down side is the need to have a clue about gas forge design; otherwise "the fool and his money are soon parted." All of these forges need some additional features added, and most of them would be greatly improved with at least, a change in burner details, or at worst, a different burner.

Whether you build or buy your gas forge, it is likely that you will need to provide your own sealing and heat reflecting coating on its internal surfaces.

Hot-face materials:

Plistix 900 is a fire clay powder consisting of 94% aluminum oxide, and 1.7% silicon oxide, with 1 to 5% aluminum phosphate as a binder; it is in many ways the premier example of a thin hot-face seal coating and is recommended for use on cast refractories and ceramic fiber blanket (but not over ceramic fiber board), it is a general service sealant that forms a protective thermal barrier for ceramic fiber blanket insulation; it air sets to a hard surface.

    Plistix is sold as powder, and is mixed with tap water to a consistency of sour cream; then dabbed on from a disposable paint brush in 1/16” thick layers (each layer will coat 1.2 square feet per 1lb. of powder).

    After application, seal equipment interior with plastic, and allow to dry slowly at temperatures above 60 degrees to a hard set. Post drying, fire the first layer and all subsequent layers can be applied with brush strokes, prior to drying and firing. Bring the coated equipment up slowly to temperature, to avoid cracking and other damage from thermal shock. Air dry and fire every subsequent layer before adding additional coats.

Kast-O-lite 30 insulating castable refractory can be troweled or cast in a 1/4” to
 1/2” thick flame face layer, giving a large measure of thermal protection, along with mechanical armoring from thicker layers, in case you are moving crucible tongs in and out of your equipment, and for general shop safety; it is use rated to 3000 F, is alumina based for flux tolerance, contains mini silica spheres to provide insulating voids, and is very resistant to thermal shock; it weighs 90 lbs. per cubic foot (compared to 146 for standard alumina refractory). Kast-O-lite 30 has been the favorite refractory for construction of home-built forges and casting furnaces for more than twenty years.

    This refractory hardens gradually enough that the edges of equipment surfaces can be scraped with a straight edge, so that those surfaces meet perfectly, allowing two part forges and furnaces to run with little flame leakage.

    Kast-O-lite 30 has a moderate insulating value of great importance for protecting insulation from heat damage; when coupled with a re-emissive (heat reflective) finish layer, it will greatly lengthen the working life of secondary ceramic fiber insulation. 

    Kast-O-lite 30 will stick to most materials. Use cooking spray, Crisco, or car wax on plastic or wood molds as a release agent. I have also used glass jars as forms, and then shattered them by heating to red incandescence, followed by a water quench, after the refractory cured. Cardboard and wax candle molds both burn away conveniently.

Heat reflective coatings: There are inconsistencies found in advertisements for "heat reflective" products; this is a legitimate label, if inexact. when, advertisements go further, and label various products as IR reflecting, they depart from reality. 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, or camera lenses.

    High-emissivity coatings can be used to more effectively transfer heat through a crucible wall (as a thin coating), or to redirect energy, forming a heat barrier in thicker coatings; to illustrate the importance of the point, we will define a typical thin zirconia coating as one millimeter or less (.039") and thick coatings as three to five millimeters and up. The critical difference between a heat barrier and standard insulation is that the higher the heat level the more effective high-emissive coatings become, while insulation typically lose efficiency as heat levels rise. Also, the thicker the coating the more effective a heat barrier becomes. Induction "furnaces" for instance, use crucibles made of nearly pure zirconia refractory, which is transparent to high frequency waves, but is so efficient as a heat barrier that with secondary insulating refractory between the electric coils and an inch or less of it outside the coils, a crucible becomes the whole furnace.

    The way a re-emissive coating works, is that it absorbs heat so redily that it quickly becomes incandescent. Think of a thin layer of tiny zirconium oxide particles exposed to a high heat source, and radiating that energy in all directions; now picture another layer of particles 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 heat source.

    So, a thin re-emissive coat will transfer 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. Re-emissive coatings are a simple but elegant form of recuperative energy generation. By converting combustion heat to radiant energy emission, heat gain from combustion is mostly retained on interior surfaces before the heated gas is lost out of exhaust vents, while heat loss through conduction is greatly reduced, with the added benefit of reducing heat stress on ceramic fiber insulation.

    Efficient heating equipment is designed for radiant energy to do most of the heating work, with part of the combustion heat saved up on the radiant surfaces, so that direct heating from a flame becomes  a secondary heat source on the work. By the time your equipment interior reaches white heat, less than a third of combustion energy is directly heating metal parts or a crucible, while radiant heat is doing most of the work. Once you understand these principles, why movable exterior baffles coated with a high-emissive layer trumps looking for the best exhaust vent size should become obvious.

    Zirconium silicate (zircon) is about one-third silica, so it takes a thicker layer than zirconium oxide (zirconia) to do the same re-emission job, but then it is also far less expensive and much easier to employ. It is a fact that the smaller the particles of zirconia the greater the percentage of heat re-emission they create (as low as 68% to as much as 95%). The zirconia particles trapped in the silicon matrix of commercial zirconium silicate are minuscule.

    Zirconia crucibles employ very crude particulates, and yet they are so effective as insulation that they become the entire furnace, when wrapped in a high frequency coil, and insulated by a further layer of loose zirconium oxide. So, the thicker the re-emissive layer on equipment interiors the better—always providing you use it in a manner that will stay attached.

    Hot-face heat reflectors can be as minimal as re-emissive coatings over ceramic board and rigidized blanket, or painted on a 1/2” thick layer of Kast-O-lite 30 cast refractory. But an armored tile of 5/32” to 3/16” thick made of homemade zirconium silicate “clay” has become a superior option, thanks to Tony Hansen’s famous Zircopax formulas on digitalfire.com: https://digitalfire.com/4sight/material/zircopax_1724.html

    If you are willing to take responsibility for understanding and using raw materials, there are a number of alternative choices, which beat the heck out of commercial heat barriers; not only costing far less money, but sometimes giving better performance at the same time.  So called IR reflectors (actually high-emissivity coatings) will be of especial help in raising efficiency while protecting interiors of heating equipment; let's lay them out.

    The most effective commercial heat reflection coating claims "up to" 90% IR “reflection.” But, "up to" is actually a cover for the nasty truth that their formula can also mean as low as 68% heat reflection; it’s all a matter of zirconium oxide particle size.

    Being a naturally suspicious type, I tried separating the colloidal content from cruder particulates in the top commercial product by spooning some of their thick mud into a water glass, and presto; the crude stuff fell out of suspension in the mixture, and immediately sank to the bottom of the glass. So, I mixed in as much more mud as would separate, and painted the thinned-out coating over a previously coated, and heat cured surface. My forge went from bright orange to lemon yellow incandescence with the same burner and regulator setting.

    When it first came on the market, stabilized zirconia flour 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 particulates are so much more effective why have crude particulates in the content? MONEY; what is commonly called zirconia "flour" is nearly 100% colloidal, and will give you the full emissivity benefit; but it's not cheap.

    Zirconium oxide flour is the most effective heat reflector available, but it changes its crystalline structure at yellow heat, from cube to hexagon and then back again during cooling, so twice a heating cycle, it also changes particulate size, which is very hard indeed on every other ingredient in a hard cast refractory; not so slowly turning them to dust. And so manufacturers of high heat crucibles (and others whose products justify the added expense) employ stabilized zirconia, mixed with a binder to make tough refractories and coatings.

Zirconia re-emissive coating: Published government sponsored experiments with zirconia coatings back in the nineteen-sixties tried a number of binders; the most successful was orthophosphoric acid (commonly called phosphoric acid); a readily available and inexpensive product that stays suspended in water; it has some interesting physical attributes. When painted unto a surface it is adhesive, and will hold zirconia particles suspended on walls and ceilings; when heated, it polymerizes, as the acid forms esters. Thereafter it remains on the surface in a vitreous (glasslike) form at room temperatures, and becomes soft and very adhesive above 365 °F (185 °C) from then on. Mixed with zirconia flour this is a highly effective heat shield, but isn’t physically tough. On the other hand, it is simple to repair.

Zirconium silicate (powdered zircon crystal), is a substance that came into popular use, while manufacturers waited decades for reasonable stabilized zirconia prices.

Zirconium silicate, consist of silicate and zirconium molecules mixed in a stable tetragonal crystalline structure; it makes an end run around the size-change problem. Both zirconium and silicate are very resistant to flame erosion; they combine to form a tough hot-face coating. Zirconium silicate starts melting and separating out into its two constituents at 4650 °F (2550 °C); finally, it is only about 75% heat reflective as thin coats (.040”). Zirconium silicate is reasonably priced; if mixed with a binder, you can build up thicker walls of it.

Zirconium silicate re-emissive coating: Zircopax 95% by weight to Veegum or bentonite 5%.

Hot-face formula: This recipe came from a potter’s supply store. It has ingredients that physically toughen, resist strong alkalis, and reflect heat. The (ingredients (by volume) are: one-part alumina hydrate; one-part kyanite (35mesh); one-part Zircopax; half part Veegum T or bentonite clay.

    With such a low heat reflection percentage, zircon doesn’t appear to be the best choice for a re-emissive coating, but its 75% reflection increases with every additional layer painted on. If you want maximum protection for a hot-face layer, or the best high-emissive coating for a crucible, stabilized zirconia flour mixed with a good refractory binding agent (ex. calcium aluminate) makes the optimal choice; it is usually purchased from a supplier like Reade Materials.

There are three kinds of stabilized zirconia. Rather than its previous price of three times the price of plsin zirconia, they are about one-third more these days:

Calcium stabilized zirconia (melting point 4892 °F (2700 °C)

Hafnia stabilized zirconia (melting point 4892 °F (2700 °C):

Yttria stabilized zirconia (melting point 4892 °F (2700 °C):

These are my favorite choices for finish coatings, but are far from a complete list of what is available. Anyone who use something else should feel free to list their own favorites.

Perhaps, you two should cut back on the chilly consumption. Now all three of us have passed gas

When we lose track, a good joke is always appropriate

6 hours ago, Frosty said:

I'd rather build a charcoal fire in the old BBQ.

As the practical choice, I must agree. However, I don't see many people, who aren't familiar with blacksmithing choosing it over a clean burning gas forge, these days

Okay, it does not begin to compare with a single burner Mister Volcano forge, which costs the same price; that is quite true. On the other hand, how much longer will the better forge continue to be offered? They have already taken their burners off the market. If we scoff at every other low cost forge, maybe there will be even fewer choices down the road?

    I look at that forge, and see how people who are reluctant till build their own forge can improve it, with little effort. Is it very small? Yes; on the other hand, people build coffee-can forges, and the even tinier two-brick forges, all the time, to build, repair, and change hand tools, and jewelry tools too.

My first burner designs used a series of holes in a line. The famous Hybrid burners, changed those series of hole to slots, improving burner performance. I came back with rectangular air openings, with beveled edges for and aft, improving them still further. However, simply cutting out the material between the back and forward hole in these burners, will turn them into air slots, which should improve burner performance more than enough for small burners.

So, what has size got to do with anything? For some reason that I do not understand, smaller burner sizes tend to run hotter than larger burners; I have had to partially de-tune my smallest burners (1/4" size and under), in order to maintain long turn down ranges.

This is the main reason that I am playing with linear burner designs again; they are more than hot enough to serve as miniature burners, and a whole lot easier for people to construct than Mikey burners.

Don't worry, though; I've already designed souped-up linear burner versions, which are much harder to build, for the determined hobbyist. Never let it be said, that I let my fellow mad scientist types down

I would lose the brick, and add a 1/4" thick finish flame surface of Kast-O-lite 30, or Plistix 900, instead.

This is a much better forge than the one I looked at; not because of its size, which is better because you will want to keep it, even after you build the "forge of your dreams." The best improvement over the other one, is that there is no angle around its exhaust openings to heat up, and be warped out of shape

As to providing parts for other forges...if you simply scribe lines between the forward and aft holes on its burner, I think you will decide to keep your "garage heater" just as is

20 minutes ago, Frosty said:

My best advice is, "Do NOT waste money on it!" It is so badly designed and built I'd be hard pressed to think of anything to use it for. Maybe hardening short blades one at a time. I'd rather build a charcoal fire in the old BBQ.

Frosty The Lucky.

People might use the e-cowlboy forge for a fancy door stop? Let's not forget to be helpful, at all times

dgr,

 I had a look, but did not find any e-cowlboy forge photos of their gas pipe and MIG tip. So, all I have to go on is my own previous experience; that tells me that copper pipe is quite unlikely to be used as a gas tube. A brass gas tube is far more likely. Old brass parts sometimes look like copper in photos. As to how they get a MIG tip with 1/4-27 thread to screw into a 1/4" outside diameter tube or pipe, the gas tube is probably 5/16" outside diameter by 3/16" inside diameter. Although, MK brand MIG tips have smaller diameter thread, which would probably just barely work in a 1/4" gas tube; hey are a superior tip, but I quite using them, because they are just too hard for people to find.

By the way, their photos show a lemon yellow incandescent interior, which is consistent with 2000 to 2100 F heat range. 2700 F interiors are white hot.

But the worst thing I see about these forges are the exhaust openings and doors. They look nearly guaranteed to warp from the heat of exhaust gasses.

I could go on picking out things I don't like about this forge...but, enough said.

"Last thing for Mike's new book.  I've seen it mentioned in your writing that mufflers are zinc coated.  I installed a few mufflers in my younger days and never saw the telltale yellow soot of zinc when welding them.  I believe non-stainless modern exhaust components are aluminized and not zinc coated steel."

Ups! Suppose I'm showing my age Thanks for the update.

Nice one, Lee.

Tell us a little bit about the bird houses. I for one, am interested. We have a garden, a bird bath, loads of birds, and three trees to place them in; but no bird houses.

16 minutes ago, Trevor84 said:

rocket tryentist.

Good one, Trevor; I like that

46 minutes ago, Frosty said:

It's funny, as tired as I got of answering the same questions over and over the recent slow spell is kind of sad.

Yes, we just never seem to be satisfied...I have had some of the same problems. We must do a better job of coaxing?

I have noticed a recent uptick in activity on this thread, but fail to see a corresponding increase in questions. Your worries aren't state secrets, or even surprising to us. So you might as well fess up, and get some answers. We all promise to be kind; really we do

Yes.

Frosty has it right. Two one inch layers crinkle far less than a single two inch layer. Once rigidized, both layers are glued back together again. So, you gain a lot of control, when installing the insulation, with no down side. What's not to love?

It must be added that what castable refractory you choose will effect the values mentioned above. Castable insulating refractory will work far better, with less fuel, than castable refractory used in glass furnaces, for instance. Also, heat reflective finish coatings are just as important as type of refractory used.