MattBower

I'm sure it could be done. Folks manage to forge weld stainless steel and titanium, after all. Do you have a power hammer? How much forge welding have you done? Do you enjoy pain? A10 looks very different from what I would normally consider a good candidate for an axe steel.

5" diameter = 2.5" radius, r. depth, d = 9". Volume of a cylinder is pi*(r^2)*d. pi*(2.5^2)*9 = 176 cubic inches. If 150 is a practical minimum for a t-burner, then your popcorn tin will just make it. Don't make your Plistix too thick. This won't be a welding forge. Not to say you couldn't weld in it (maybe you could, smaller stuff), but you'd probably want to build a bit heavier for welding. By the way, open-ended on both ends with movable doors of soft firebrick -- I'm just talking about setting a firebrick or two in front of the opening, nothing fancy -- would be a good idea. That way you can pass work all the way through the forge, and the door openings will be ajustable. You'll have to experiment to figure out how much you can block the openings without choking the burner.

I suggested warm water because many of the alloy spring steels aren't really intended for fast quenchants like water, and warming the water up will slow down the quench speed. But if it survived, it survived! (Quench cracking can have a lot to do with the geometry of the part, and punch geometry is pretty simple. That may have helped you.) As for cracks, quench cracks should show up pretty quickly. If the steel is too hard for the use you're giving it that can also cause it to crack, and those sorts of cracks may not show up right away. But if you're hot punching, the punch is going to receive extra tempering in use anyway -- to the point that you will probably have to reharden it occasionally. So if you've made it this far, just use it for a while and see how it goes. Wear eye protection!

The best price I have seen on soft firebricks, anywhere, is Wayne Coe's. http://waynecoeartistblacksmith.com/ Just today I have been exchanging emails with him about buying some bricks. He can beat the price of my local ceramics supplier, and that's after shipping and insurance. (Come to think of it, that doesn't even take into account state sales tax!) I would expect that you could do a lot of bladesmithing in a coffee can forge, although kraythe is right that your current burner may be a bit overpowered. I do nearly all of my forging these days in a coal forge, and the hot spot is probably no bigger than what a coffee can would give you. The main down side I see to a coffe can is that you wouldn't be able to heat treat longer blades. But it'd get you started on everyday users. And your t-burner might just be tunable enough to operate in a forge that size. Phil or Frosty, or someone else who has actually built one of those burners, could give you better input on that.

What you describe does not necessarily indicate an exceptionally high temperature in the forge. Was the Kaowool lined with hard refractory?

I agree that lining it with full-sized hard firebricks would not be a good solution. Too much mass and too little insulation that way. You could probably get away with hard firebrick "splits" (which are about 1" thick), although even those would be more massive than you really need. Lining the forge with soft (insulating) firbricks wrapped in Kaowool would probably work really well in terms of insulation, but just adding another layer of Kaowool with a skim coat of a castable refractory, and ditching the bricks altogether, would be a simpler solution and probably end up costing about the same. Since you already have Plistix on your to-buy list, I assume you're already planning a thin hotface made of hard refractory. kraythe's suggestion of a brick pile forge made of insulating bricks really isn't a bad one to get you started. That way you wouldn't be locked into one particular forge size or geometry before you've had a chance to learn what you really need.

Water may be too severe a quench for your steel, but since we don't really even know what your steel is, that's just speculation. Let me suggest that you at least use warm (say, 120-130 degrees) water for the quench. That'll help tame it a bit. Take the steel to just a shade beyond nonmagnetic before you quench. Self-tempering by letting the colors run, like FF suggested in #8, may work, although it makes me nervous. Once the piece is cooled to room temp, inspect it very carefully for any sort of cracks -- even extremely fine ones -- before you put it into service. This is a very rough-and-ready HT. It won't work well with all steels. But without knowing what specific alloy you have, it's impossible to recommend a process that's guaranteed to work well.

Zachary, (1) What size are the firebricks, and how are you planning to use them? Floor only, or something more? (2) Think seriously about another layer of Kaowool. A 5 gallon bucket is about 12" in diameter. One layer of 1" wool will cut it down to about 10" inside diameter. That still leaves you comparatively large, poorly insulated space to heat. You will save yourself a lot of dollars on propane in the long run by making the interior smaller and better insulated. By my math, adding another layer of insulation will cut the interior volume of your forge by about 396 cubic inches -- that's more than 1-1/2 gallons! And it'll be much better insulated, too. An 8" ID forge is still quite a bit larger than you need for forging most blades. (3) You can save money on the flare by casting it right into the interior of your forge. You really don't need to buy a machined stainless flare unless you want to run the burner outside the forge. You might put that money toward insulation. Just my $0.02. Matt

Nobody can really answer your question. You will have to test and experiment. Down side of using mystery steel.

I agree. 3000 might be doable with a serious preheat of the combustion air, but I don't think it'd be an easy build.

Correct; hard firebricks are dense, and thus relatively poor insulators, just like castable refractory. Also be aware that not all firebricks are created equal. Find out what the temperature rating is. The common firebricks that are sold for fireplaces are rated something like 2000 deg. F. I get them from a brick yard for a little over a buck a piece. But for forge use you'd probably want something rated more like 2300 or 2500 deg. F. If you put a blower on venturi burner, you have a blown burner. In which case, why not build a blown burner? What you propose might work if you closed off the air intake for the venturi when you turned on the blower. I have an intuition it might not work so well if the venturi air intake were still open, As for forming the hole in your ceramic blanket, one way to do it is to make a flare-shaped wooden plug that fits into the end of your burner tube, coat it with a release agent (like Vaseline), then stick that in the hole and mold castable around it. Once the castable hardens, pop out the plug and you have a castable refractory flare, which also locks in the ceramic fibers around the opening.

3500 F is way beyond the pour temp for cast iron, actually. In fact it's quite a bit hotter than the pour temp for cast steel!

Yeah, be aware that iron is soluble in lots of common metals when they are molten -- including aluminum and copper alloys. That's why steel crucibles don't last that long even if they're being used at relatively low temperatures. The charge dissolves the crucible, and it will indeed contaminate your melt. It's a bit like melting ice in a crucible made of sugar. These guys have good prices on proper ceramic crucibles, and if you treat them right they'll last a lot longer than homemade steel crucibles: http://www.lmine.com..._Code=crucibles A couple notes on melting brass cartridge cases, from experience: Dry them really well with a very thorough preheat. The fact that they're hollow makes them especially well suited to holding water, and adding a case with water in it to your molten charge is exciting in all the wrong ways. Expect to lose a great deal of material to dross. Using a couple tablespoons of crushed glass as a cover flux seems to help minimize the formation of zinc oxide (the white smoke someone else mentioned, which you want to be careful not to inhale). And it gives you a good excuse to empty a beer bottle or two. I'm fairly sure I once had a live or partly live primer in a load of fired brass, which I discovered when I added the case to the crucible and something went "bang." It sure sounded like a primer going off, at any rate. It scared the heck out of me and could have done much worse, I'm sure. (I'm certain no one had begun reloading those cases, so if it was in fact a primer that I heard, I have to assume that it was some leftover priming compound that, for some reason, didn't get consumed when the cartridge was fired. I was careful to screen the load of cases for duds, so I'm pretty sure that wasn't the problem.) Again, I think a really thorough preheat would've solved the problem before that case went into the crucible.

As I already said at least twice, if you are doing multiple quenches there is no reason to repeatedly normalize; repeated quenching to martensite can accomplish the same thing, and faster. But the down side to repeated quenching is the risk of losing the blade to quench cracking. There are less risky ways to accomplish the goal. Beyond this, some of your complaint seems to boil down to semantics. You think that what I'm doing isn't "normalizing" because it doesn't look exactly like some of the normalizing recipes you've seen. That's what I get from your second-to-last paragraph, above. And that's true: some of the recomended normalizing cycles I've seen, and that you're referring to, call for a soak at temp -- and at a higher temperature than I am using, too. (Frankly, I don't understand why they recommend that because, as you yourself suggest, the relatively high temps and long soaks would seem to invite grain growth in simple steels. I can understand something like that in hypereuctectoid steels to get the carbides into solution, but I would want to follow it with grain refining cycles.) But with that said, "air cooling is often called normalizing," (Verhoeven, 32) and "the data on normalized (air cooled) steels illustrates two general characteristics (ibid., 38). There are other examples in Verhoeven in which he uses the words "normalizing" and "normalized" as essentially synonymous with "air cooling" and "air cooled" (from austenite, which is implied but not always stated). The Heat Treater's Guide says, "in a thermal sense, normalizing is an austenitizing heating cycle, followed by cooling in still or agitated air." (Ibid., 27.) It also says that, "Normalizing is applied, for example, to improve the machinability of a part, or to refine its grain structure . . . " (Ibid.) So, putting it all together, an austenitizing heating cycle followed by cooling in still air (air cooling), to refine grain, meets these simple definitions of normalizing. And that's exactly what we're doing. So I continue to think it's completely legitimate to call this type of thermal cycling normalizing. Last, you said (to me) that, "You are the one that pointed out that large grain is harder see your quote below." I'm not sure where you're getting that. The quote in question is below. I see the word "hardenability" three times. I don't see the word "hardness" at all. I did say in an earlier post that it is possible to refine grain so much that it becomes difficult to properly harden a blade. Hardenability can affect final hardness, but I never suggested they're the same thing. Let me add one final thought here. Industry has developed a lot of heat treating methods that simply aren't reproducible with the extremely simple equipment most of us are using. If you have a kiln or proper heat treating furnace with good temperature measurement and control, you can do a lot of neat stuff, and work with a lot of steels that are out of reach for most of us. (This is the main reason I still avoid working with steels with more than about 85 points carbon.) But since most of us don't, folks have developed simplified techniques to get close to some of the industrial methods while accommodating the limits of our equipment. The fact that they're simplified doesn't mean they don't work, when executed properly and applied to the right steels.

Woody, I have other things to do today, so this will be my final post on this issue. Bottom line: I'm starting to suspect that you're arguing just for the sake of being contrarian. Here's why. First, your questions in your previous post make it obvious that you don't know the difference between hardenabilty and hardness, or understand the basics of the interaction among grain size, hardenability and brittleness. That's Ferrous Metallurgy 101 stuff. I'm a huge proponent of getting rid of the "alchemy and blacksmith hearsay" in our craft, but the first step in that is at least a little self-education in metallurgy (for those of us who don't have the option of getting formal education in the subject). If you have read Dr. Verhoeven's work, you apparently haven't absorbed it, or you'd understand that "large grain = harder metal" isn't an accurate summary, and that large grain comes with a serious down side. (By the way, triple quenching and triple normalizing, all in a row, is vast overkill unless you're doing something funky with your steel, and I don't recommend it.) On one level, that's OK. I printed my copy of Verhoeven's book more than five years ago, and there's a lot in it that I still don't understand. Even as much as Dr. Verhoeven tried to dumb his subject down for guys like us (and he dumbed it down a lot), it's still far from a simple read. I don't blame anyone who doesn't "get" all of it. But until you have a handle on some basic principles, you ought to be careful about writing off as "alchemy" things that you don't understand. Second, you've established an absurdly high standard for belief, which strikes me as nothing more than a tactic to justify your position. If your standard is that you won't believe anything written here unless it's suitable for publication in a peer-reviewed academic journal, that's fine, but that means you'll believe almost nothing written on IFI about any subject. And I am very skeptical that you really adhere to that standard. That's a reasonable standard when we're trying to prove some totally novel scientific theory, but that's not what we're doing here. Which leads me to my third point. Third, you asked for a "documentable reference" that confirms the benefits of repeated normalizing. You already have it; you named it yourself, and I pointed out to you a couple of specific paragraphs that support the practice. You respond by misreading the text in order to avoid having to come to grips with what I gave you. For example, you say that "Verhoeven quenched in rapidly stirred oil." That comes froms Verhoeven's description of one experiment, in which the goal was to form fine-grained martensite. As I explained to you in my previous post, Verhoeven, on the very page you're reading, discusses two separate things: how to form fine-grained pearlite/ferrite, and how to form fine-grained martensite. You're quoting from the paragraph on martensite in order to try to craft an argument that quenching in rapidly stirred oil is necessary in order to form fine-grained pearlite/ferrite, which is what we're trying to do when we repeatedly normalize prior to hardening. I tried to preempt that sort of confusion in my previous post, when I wrote, To be fair, I probably should have added, "for most simple steels in blade-sized cross-sections." In really large sections, cooling in still air might not be fast enough. Regardless, though, all you've got to hang your hat on is the idea that air cooling isn't fast enough to achieve the pearlite/ferrite grain size reductions that Verhoeven is talking about in blade-sized cross-sections. But Verhoeven doesn't say that. He leaves it somewhat ambiguous (because he's teaching principles, not writing recipes -- more on that in a second). You just want to read it that way. You see, I don't think you're actually looking for a metallurgical reference that supports the concept of repeated normalizing. I think you're looking for an end-user manual that gives you a recipe that involves repeated normalizing, and until you see that, you're going to write it off as witchcraft. But real textbooks don't give recipes; they teach principles, which it's up to the reader to apply to a specific situation, taking into account all the relevant variables. That's why Verhoeven wrote a roughly 200 page book that's heavy on theory, rather than simple heat treating instruction sheets for the 20 or 30 most common blade steels. End-user publications like the Heat Treater's Guide simplify principles into recipes that can be applied by folks with minimal knowledge of metallurgy. And that's great; I'm a big fan of the Heat Treater's Guide. It contains tons of useful info. But as has been discussed here many times, it's oriented toward a particular type of end-user. And in order to come up with its recipes, it necessarily relies on some assumptions about how those end users are going to operate. I am certain that it does not assume that end users will be treating their steel like we bladesmiths do during the forging process. That's all I have to say on the subject. You believe what you want. But I am going to continue to promote repeated normalizing (within reason) to reduce grain size and improve toughness because I know first-hand that it works, and because I know that there is a solid metallurgical foundation for the practice.

It's not a video, Woody. If you actually "watched" it I don't know how you could think that it is. Second, you're wrong that it's not repeatable. The write-up clearly states that the steel was heated just to decalescence, removed from the forge, and allowed to air cool to black. You're telling me you don't think you can manage that? The decalescence point is better known as Ac1. It will vary from steel to steel, and with heating rate, but it marks the transition to eutectoid austenite (although not dissolution of carbides in hypereutectoid steels). The neat thing about it is that, with a little practice, you can see decalescense happen, which is the technique they used in that experiment. (This is easier to see in some steels than others. The reason the phenomenon can be visible has to do with latent heat of phase transformation.) But if you happen to have a kiln or HT oven and would prefer to run the experiment in a way that doesn't require you to actually observe decalescence, I'd be very happy to help you set up the experiment. Now, the thing that really confuses me is that you're citing Professor Verhoeven for the principle that repetitive heating and cooling cycles reduce grain size, but you're also rather aggressively challenging a claim that repetitive heating and cooling reduces grain size. Multiple quenches will accomplish the same thing as multiple normalizing, and faster [edit: when I say "faster" I mean that starting with two identical samples of a fairly large grain size, heated to the same appropriate temperature, if you air cool one and quench the other to martensite, it's my understanding that the martensite sample should have a slightly finer grain, although both will be smaller than the original sample] -- but of course normalizing doesn't carry with it the danger of quench cracking, which is why I, for one, prefer to normalize repeatedly rather than risking multiple quenches.But don't take my word for it; let's go back to Prof. Verhoeven, on the very same page you're relying on: Bear in mind that we're talking about forming fine pearlite grains here, so we have to read carefuly enough to realize that when he says, "cooling back to room temperature as fast as possible," he doesn't mean "so fast that we form martensite." Thus, at least with respect to steels with sufficient carbon to harden, he can't be referring to a full quench like we'd do if we were hardening. "As fast as possible (without forming martensite)" is a reasonable description of air cooling for most simple steels. (As you pointed out, multiple cycles of quenching to martensite would in fact work for grain refinement, too, but that's not what Prof. V is discussing in this pargraph. Here he's talking about forming fine-grained pearlite and ferrite, not fine-grained martensite.) In fact I suspect there's a typo in that paragraph; I think when he wrote, "without forming bainite," he meant martensite. The reason I say that is that rapid cooling isn't something we normally associate with bainite formation; to get much bainite we normally have to quench fast to below the pearlite nose, then hold a little above the martensite start temperature for a very long time. So it doesn't really make sense to me that he'd be worried about bainite formation in this context. Martensite, though, is a different matter. But I could be missing something there. Please also note that, a few lines further up the page, Verhoeven explains that "new austenite grains begin to form on the old pearlite grain boundaries as shown schematically in Fig. 8.4." If, as Prof. Verhoeven says, repeated heating and cooling into and out of the austenite region reduces the grain size of pearlite, and new austenite grains begin to form along the boundaries of exisiting pearlite grains, and if the austenite grain size determines the grain size of martensite after we quench (which it does -- he addresses that at the beginning of the final paragraph on p. 69), then it's no mystery that forming fine pearlite as described above, followed by heating to the appropriate transition temperature and quenching to martensite, will produce fine-grained martensite. That's exactly what we're doing with multiple normalizing cycles, followed by a quench to harden -- assuming we execute them properly, of course. Finally, you say that "the last I knew, repeated quenching did not make the steel less hardenable." We have already established that repeated quenching makes grain size smaller. You seem to agree with that proposition, at least. So let me quote Prof. Verhoeven from p. 83 of the very same book you're relying on: So let me ask you: if increasing grain size moves the start curves on the IT diagrams to the right, indicating greater hardenability -- which is what Professor V just said -- what must we necessarily conclude would happen if we reduced grain size? Which way would the curves move, and what would be the effect on hardenability of the steel? Remember: we've already established that changing grain size moves the curves, and that moving the curves affects hardenability. So . . .

Yes, I posted that. http://paleoplanet69529.yuku.com/topic/47099/Normalization-Grain-Size-Control-Experiment-----normalize Metallurgy does explain how and why it works, but it's a little more complicated than I think I can adequately explain. (By which I mean that I don't completely understand it myself.) It has to do with nucleation of new austenite grains along the old austenite grain boundaries. (And austenite grain size determines the grain size of the room temperature structures like pearlite and martensite.) So if you form a bunch of smaller grains by one normalizing cycle, then austenitize again, the new grains will begin to form along the boundaries of the old grains -- and they'll necessarily be smaller than the previous set, at least until grain growth kicks in. But there is some practical limit to how far you can go with this -- or how far you'd want to go, since the finer the grain size, the less hardenable the steel. It is possible to refine grain size to the point that the steel will not harden properly, at least in some steels.

Don't have an answer for you. I did try to do a little research earlier, and I learned that 1018 has more manganese than 1020 typically does. (0.6%-0.9% Mn for 1018, 0.3%-0.6% MN for 1020.) I was thinking that 1018 with carbon in the high end of the range (.15%-.2% for 1018) should be a satisfactory substitute for 1020, but I guess you'd also have to watch the Mn content. I also found this, although I don't know if it is the applicable standard for what you are doing: http://www.scribd.com/doc/56014965/8/Metallurgical-Structure Can't tell you where to buy the stuff, though. I hope this helps.

Gorgeous hamon, Justin, and an awesome blade all around. Is that Aldo's W2? This may be your first Bowie, but clearly this ain't your first time at the rodeo. :)

I just watched that ABC vid. That's a nice-looking little bottle opener.

It's also possible that there's no prohibition on your father possessing swords at all. Edged weapons aren't nearly as highly regulated as firearms. But this is one of those times when you shouldn't count on the advice of strangers on the Internet.

Hate to say it, but it depends what you're welding. For wrought iron and mild steel, when the flux is bubbly and smokey when you pull the piece from the forge, that's a very good sign. Welding temps for higher carbon steels are somewhat cooler than wrought or mild. But I still have problems welding those steels sometimes myself, so I'm not the right guy to give advice on that. You can also use a probe to test welding temp. Take a piece of baling wire or a small diameter rod with the end forged to a point. Get it hot, put a little flux on it, and touch it to the work piece in the forge. When it wants to stick -- firmly -- to the work, you're about where you need to be. (Thicker work may need to soak a little to let the interior temp catch up.)

Legal advice is cheap on the Internet, and "you get what you pay for" is a good rule of thumb when the answer really matters. I second the suggestion to consult with a Washington attorney about this. You can also start with Title 9 of the Revised Code of Washington. http://apps.leg.wa.gov/RCW/default.aspx?Cite=9

You want to grind out the teeth on a rasp or file if you're going to forge it. Otherwise they'll want to cause cold shuts. Just a tip, since it doesn't sound like you did that this time.

That's good. I still think it's likely that you tried to weld at a temp too high for that steel. Consistent lighting -- preferably with decent shade -- will help you judge color. Some folks who work outside build a hood over the forge to deal with the problem.