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Everything posted by RedNeckLeftie

  1. Let me make sure I understand this: You can use a purely *flat* piece of stock, and just grind the top-side angles in? I actually used my bench grinder to put an arc into the bottom side. Spring steel tempered to 400F, that's about how hard? I went for ~62-63 HRC with a piece of Admiral 1095--darned if it don't need sharpening again... Sam, I have never gotten any deep gouges, just occasionally removing more shavings if I tilt the "back" of my sen for more "bite" ("back" being NOT the side I am scraping with). With a two-sided sen, you can actually scrub up-and-down to remove metal on both strokes. Thanks, Brian K.
  2. Hi John, Yep, the specific Texas statutes are Section 46 (Weapons) of the State Penal Code. Mind you, I am NOT a lawyer, but to me it means any non-switchblade knife, fixed or folding, less than or equal to 5.5" blade length is legit. The state law is pre-emptive, but beware: San Antonio has seen fit to egregiously flaunt the state law and enact its own far more draconian knife "ordinance." Essentially, no hunting or "Buck" knives, last I heard anyway. I guess it hasn't been challenged in state court yet? I've also found that police are very hit-or-miss on the regs, maybe they figure it's safer not to let the cat out of the proverbial bag. And like Allan says, the cops I've known have a big drawer full of variously-sized knives (fortunately or unfortunately, they are always those really crappy bucket 'o 420J2 specials). All my friends and coworkers know I'm a knife-nut, so we kinda joke about me carrying ~5" blades everyday. Of course, when they need a knife... Brian K.
  3. Hi Ethan, What kind of clay are you using? If it is potter's clay (Amoco, Marblex), you may have serious problems with cracking. That is what I started with, and once I discovered satanite, gave up on other stuff (have not been able to try terra cotta, though). I tried adding carbon and limestone to no avail. If you can, I recommend satanite to start out with, you can get it from Darren Ellis, www.elliscustomknifeworks.com. If your really want to go the "natural" route, the Japanese typically used some variation of clay, carbon, and whetstone powder. Of course, "whetstone" here really means waterstone powder. Before switching, I had an almost usable concoction where I added waterstone to the mix. This "waterstone" was leftover powder from working a 220 Grit Norton waterstone, so YMMV. Natural Japanese waterstone waste may give better results. I think adding rust would be a bad thing. It may promote oxidation during heat-treat. Mentally, it "feels" wrong--though I have no science to back it up... Thanks, Brian K.
  4. Hi Steve, I have to keep reminding myself this is a blade-FORGING group (for the most part; I am a "lowly" stock-removal fella). After re-reading the posts, I understand the predicament, and that thermocouples would not be the cleanest solution. Thermocouples tend to take their own sweet time stabilizing on a temp reading, about 35 secs. I certainly hope you are successful with the IR thermo, please do post your results. If it's good enough, I may have to spring for one as a backup check. Thanks, Brian K.
  5. According to cheaperthandirt.com (great site), the military quit using them because they were afraid they violated the geneva convention. CheaperThanDirt sells a pound of them for ~$25 (ask me how I know )
  6. Hi Luke, I see what you're saying, it makes good sense. I was just regurgitating my knowledge (gained from here). It's a pretty safe bet many of us cannot do a 40F/hr cooling. I may have to experiment with furnace-cooling versus air-cooling to see if makes a difference in the end product (grain, strength, etc., now I have too many experiments, I'll never make a blade ). Thanks, Brian K.
  7. Hi Steve, I believe that unit also has a fixed emissivity of 0.95. The point I was trying to make earlier (and kinda failed at) was that the emissivity can severely impact the accuracy of the measurement. While the unit may have a basic accuracy of 1.5%, the "practical" accuracy could be as bad as 30-50%, especially above 1000F--like Bennett's experiments above. One thing these IR manufacturers suggest it to make/leave a hole in the "work," and take a measurement of the temp of the hole, since this will closely approximate a black body radiator. The hole obviously has to be at least as big as the unit's field-of-view at the given measuring distance. Personally, I would recommend thermocouples for temp sensing. They tend to be very accurate, and are not impacted by external considerations. These can be had from Omega (www.omega.com). Some thermocouples can even be hooked to a digital multimeter, where the voltage indicates the temp. I use an electric HT oven, so mine came with a thermocouple--might check Paragon's web site to see if they sell thermocouples as spares... Thanks, Brian K.
  8. jkv, Depends on the steel. For most all carbon-steel (10xx), you want to air-cool to normalize. You use a furnace-cool or vermiculite to anneal. 5160 has a helping of Chromium, so it tends to air-harden somewhat--which means that you want a slower cool to normalize it. Thanks, Brian K.
  9. Welcome back, glad you are in one piece, and thanks for your service! Brian K.
  10. Hi Guys, You need to be VERY careful using any of these IR/Black-Body temp units. Their accuracy is at best very, very loose. The best unit I have seen (~$500) was about 0.75% basic accuracy. If it read 1550F, the "real answer" was 1538-1561F. Now, that is under "perfect" circumstances. These units rely on a physics property known as "Black-Body" radiation. Basically, it means that an "anus" of space, in a vacuum, will radiate a specific amount based soley on its thermal energy (what we usually call temp). If, however, something other than space is being heated, the radiation (light emission) will change. The amount of change from ideal vacuum is referred to as emissivity. The high-end IR temp units will have an adjustable emissivity (to compensate for your particular target material), but this is not enough. It turns out that emissivity for a given material, including steel, changes with temperature! (Steel emissivity can vary from 0.07 to 0.85 depending on alloy, rust, level of polish, and temp from 200-3200F.) I originally thought these things would be the cat's @ss for gauging quench temps, then I cranked the numbers--it is not a pretty picture. Best of Luck and Wishes, Brian K.
  11. Hi Bennett, I guess that Knovel source buttoned it up for you? Don't know if it helps, but if you check out "The Microstructure of Steels and Cast Irons" by Madeleine Durand-Charre, pp. 42-45 gives a bit of a definition (go to amazon and do a "search inside"). The book's a great read if you're having trouble falling asleep on the crapper. In a nutshell, it suggests there are several "intermediate phases" in steels: Carbides/Nitrides, etc., are one type--"semi-metallic compounds based on difference in electronegativity"--and intermetallic compounds are another. It seems intermetallics are often electron-shell bonds, where Group VIIIa elements can accept electrons in their "d" shells, and Group IVa, Va, and VIa elements can be "d" shell electron donors. Intermetallics can also be governed by their atomic sizes. (I'm no metallurgist, so if I just confused the issue, I apologize). Thanks, Brian K.
  12. Hello Robert, I have been "playing" with some Admiral 1050 for a while, with a Paragon heat-treat kiln. What I have found necessary to get a good clay-following habuchi is about 1470-1480F @ 30 sec soak before quench. I do not have much experience with 1095, but plan to do so soon. Thank you for posting your test results. Regards, Brian K.
  13. Hello Maolan and Scott, One thing you guys might want to try is the "magnet test." Others have mentioned it here elsewhere many times, but the jist is this: When steel reaches it hardenable crystal structure (austenite), it loses magnetism [this assumes you are using plain carbon steel, no stainless or high-alloy variants]. While heating your work, test it with a magnet. Once the piece uniformly reaches the non-magnetic state, give it a few more seconds of uniform heat, then quench it. Then you are ready for tempering. EDIT: This, of course, is after you have annealed/normalized the work. Thanks, Brian K.
  14. Hi Robert, Have you had a chance to try out the 1095 test-bars? I'm curious of your results. Also, what is your heat source? Thanks, Brian K.
  15. No problem, I work with this kind of stuff in my day-job. Yeah, the card edge fingers start with 1 or 2-oz Cu (0.0007 or 0.0014-inch), are plated with Ni, then with Au. As for the "pins, that rise from the card," I believe these would be header pins--0.025-inch sq, with 0.100" spacing. Stop reading now if you don't want your buzz harshed... According to 2 mfgs' datasheets, the pins are phosphor bronze, electroplated with 50 micro-inch Ni, then electroplated with 30 micro-inch hard Au. It's also possible (but unlikely) the base metal could be Beryllium Copper. I cut into a header pin today for fun, and yep, it cuts and looks just like gold all the way through. For fun, I dunked a complete pin in ferric, the color did not change except where plating was missing. Regards, Brian K.
  16. Hi Christoph, Electronics Industry standards for card-edge fingers (back to at least 15yrs ago) offer 2 options: 30 micro-inch of electrolytic (hard) gold over 80 micro-inch Nickel (0.76um Au over 2um Ni). A more recent alternative, they could be 0.05-0.75um Au ("flash" gold) over 2um Ni if an electronic contact grade corrosive lube is used. Not much gold in there...good luck! Thanks, Brian K.
  17. I have been trying to nail down hamons in 1050 for about a year now. According to the analysis, my 1050 has 0.69 Mn and 0.52 C. In my limited experience, it seems there may be two issues. All of my hamons look pretty much habuchi-only, ashi don't show well, hamons follow the clay exactly, but will stand out quite well with a good dip or three in the ferric pool. (I'd rather have more traditional hamons, and use hazuya, but it ain't coming along so well). As for only getting hardness halfway up the blade, my own failures would suggest the profile left too much "meat" near the tang and/or centerline that was clayed, and possibly that the clay was too thick--allowing the meat to temper the edge during quench . I am very slowly learning to get the clay under 1/8" (~3.2mm) thick.
  18. Hi Jerry, I have the smallest of the paragons (8.5" x 4.5" x 9" chamber). Of course, I am only doing smallish knife-like things with it. Someday, when I migrate to the longer stuff, I would look at the 24-incher. The one I have is a 120V/20A unit, and at full-ramp, hits 1550F in ~25mins. The controller is real easy to use with programmable ramp rates and set points (I think it's 4 ramp-hold segments per firing). I don't know about Evenheat, but the controllers do not appear to have enough buttons for complex operation--someone know diff?? Just FYI, trying to soak for 5-12mins at temps >1000F (with full-ramp) is a bit dicey. The overshoot from set-point is only ~5-10F, but on rebound it can drop 50-65F before stumbling back to set-point. This might be an issue if I tried doing high-alloy or stainless. Drawing at 750F (1500F/hr ramp) doesn't have any over/undershoot. (Naturally, YMMV). I cannot go from quenching straight to tempering in my oven. The oven don't cool down fast enough, and forced-cooling would be bad for the unit--I use my kitchen stove for the first temper cycle. Another thing, I seem to fight a fair amount of de-carb (anybody else?), even using carbon-loaded satanite "clay." The paragon guys do sell a reduction-firing kit (for running inert gas in the furnace), but it will supposedly shorten the life of the elements...so I haven't tried that route. Last thing, the outside metal of the unit gets way too hot to touch when doing a normalizing or austenitizing heat--don't want flammables too close to it. Thanks, Brian K.
  19. Hi Jake, Aren't Sgian Dubh (is this actually pronounced "skee-an doo"?--serious question) double-edged? If so, I don't think you would have a problem with water-quench sori, since you would theoretically want reasonably balanced clay application. If not, or if you must use oil, look for something with very low viscosity and high specific heat capacity, like automatic trans fluid. At least in my experience, 1050 needs a real harsh quench to harden to a useful edge. (Edited w/additions) Thanks, Brian K.
  20. A stress-riser would be any sharp point, edge, flaw, or other abrupt change in the steel that is intended for hardening. These tend to promote quench-cracks or other fatal flaws. Since you have mellowed-out the edge nearest the user, you are less likely to have HT problems (assuming this is hardenable steel). The pics look like a fracking-good blade. Brian K.
  21. IMHO, I've found it makes a difference how the surface is worked: Assuming satanite for "clay," I can go to no more than #120 US when using EDM sticks, or up to #240 JIS when using waterstones. My fine Nicholson file is way too smooth even with draw-filing--my Craftsman Bastard Cut file leaves a better surface. Thanks, Brian K.
  22. Are the parts too large for a good WD-40 soak? Sorry, can't help with the braze/weld question: Just how "old" is old? If it's more than 30 yrs, would guess the cog/blade is cast iron = PITA to weld. Hopefully, someone more useful than me will be able to reply... Brian K.
  23. I haven't used Wx steel or oil quench, but I can take 1050 down to ~0.020-0.030" thick edge without "ting" in water quench. However, I suspect I can go that thin because I use an electric kiln, and suffer from decarb--I lose about 0.010-0.020" of "mild." I ain't sure if this is a curse or a blessing (easier to just file off "mild" steel, but does this decarb hurt the hardness of the "good stuff" underneath...too many experiments to run). I did do 1095 once (close to one of the W's, don't recall which), suggests that a range around Don's suggestion is dead balls-on. (Of course, Don is about a thousand levels above my skills/know-how ). Brian K.
  24. Darn-gummit, Walter, I wish I could get my knife-hamons to look half that good and active...job well done!
  25. Hi Guys, thanks for all the pointers. I'm pretty sure I've found the problem, short answer = decarb. Now I got to figure out how to fix that mess... Long answer, HT'd a test piece this weekend. Normalize from 1600, then from 1540. Then coat and quench from 1480 (20-30sec soak) into 100F water. File test says it's all less than 40 Rc. So, I took a normal file and started working the edge. Sure enough, got down about 0.010-0.020 inch and it starts "skating." Cleaned up the other side, file tests say edge ~50 Rc, "hira-ji" less than 40. Also did a ferric soak, the uncleaned side actually got darker at the edge, not the hira-ji--you can see it in the picture. I guess I subconsciously have been trying to reduce pre-HT edge thickness to a minimum that don't "ping" but doesn't need 3 days work on coarse stones. Guess maybe I shot myself in the foot?
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