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      IMPORTANT Registration rules   02/12/2017

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About StevenRS

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  1. So, finally had some free time to get out in the workshop, and I have results! So, first off, the 14 inch blade. Annealed three times from 1500, 1475, and 1425. Held at 1475 for 10 minutes then quenched in a 1.5 percent by volume solution of laundry starch in water. No agitation, just in and hold. Unfortunately, the quenchant was too slow and I had more of a quench line than a hamon. I forgot to take a picture of the clay, but it was solid about 1/4 with gentle waves going another 1/4 out. Didn't follow it at all. Instead of leaping blindly forward again, I forged a small tanto and decided to get the quench dialed in with that before I redo the bigger one. After torturing a poor piece of mild steel for a few hours, I found something satisfactory and repeatable. Lowering the concentration of starch is a no-go because any lower and there is not enough to disrupt the vapor jacket, even if the boiling phase happens faster. So, lets add some jet dry! Bad idea. The quench literally sounded like someone tossed a bunch of marbles in a blender. I could literally feel the steel vibrating in my hand as hundreds of bubbles formed and collapsed in an instant. In fact, a significant amount of liquid was ejected from the bucket. Next, I tried salt. Sorta a hybrid polymer/brine thing I guess. I started out with 1 percent starch and 8 percent salt, and this worked pretty well. It didn't shatter my piece of 1095 shim, but it warped it pretty badly and it still sounds awfully violent, though not as bad as straight brine. I decided to find out how much starch I can add to brine and make it too slow to quench the previously mentioned chuck of w-2 so I can find an upper bound and work down. Turns out its right at 8 percent- any more and the corners don't even harden. I ended up going with 8 percent salt and 3 percent starch- its really just a gentler brine quench. There is literally zero vapor phase, and the boiling phase lasts for around 2 seconds and sounds like someone is pouring rice on concrete from a few feet in the air. Finally, here is the result- my first hamon, actually! Its not quite done yet, but I had it at 80 grit and I could see the barest hint of a hamon, so I hit it with 220 and dunked it in a nitric acid/picric acid/ethanol solution for a few seconds and got this. It followed the clay this time, so that's progress! I am not sure what exactly is what, maybe someone who knows more could help me out. All I know is that it's all shimmery and changes colors based on the angle of the light. Ideally, I would like to tailor the quenchant to produce maximum activity and get those amazing clouds and feathers that I envy to an unhealthy degree.
  2. RR steel was actually the first steel I ever worked with. In fact, I started blacksmithing simply because I had a bunch of it lying around and wanted to make stuff out of it . It's a bear to break down into usable chucks, but once you do, it's wonderful for anything that needs toughness. I treat it like an oil hardening version of 1075. A long time ago, me and my dad used a leaf blower and a bonfire to heat up a 3 foot section to red heat and drug it through a shallow pond with a chain and a tractor. After, you could score it with an angle grinder and snap off pieces with a sledge hammer, wedge, and bad language. Sure beat grinding on it all day though!
  3. So, a bit more info on the starch based quench. I successfully quenched a section of one inch wide, 0.015"(!) thick 1095 shim stock to glass hard without it cracking. The same test sample literally exploded in brine and warped so badly in warm water it looked like a section of corrugated roofing. I also quenched a 6" long section of 3/4" x 1/4" w-2 in both starch and warm canola. Before tempering, I was able to crack the starch sample in half but unable to do the same for the canola. If I am understanding the metallurgy correctly, this indicates the canola just isn't fast enough for that cross section. I really, really like the starch. It's literally a cup of sta-flo liquid laundry starch from walmart in 5 gallons of water. Total cost? It comes in right under 8 cents a gallon. Next, I have a 14 inch short wakizashi shaped object in w-2 with clay that I will post some pictures of before and after. Hopefully, no pings or warps! This is far and away the longest blade I have ever made (as well my first attempt at a more traditional Japanese shape) so I may be jumping the gun a bit, but the thermocouples arent here yet and I have poor impulse control.
  4. So, I know that most people recommend oil for quenching, and furthermore, people who really know what they are doing insist on using commercial quenching liquids. That said, so many people (particularly hobbyists) still quench in water or canola because either they can't get a commercial quenchant or they simply like water/brine. Personally, I've had issues with canola completely hardening 1075 and w-2, and the hamon tends to not follow the clay very well, if at all. Enter my current endeavor. Partly just for fun, partly because I can see real benefit out of it- Finding the ideal water based quench that I can make/find/source from local stores or amazon for less that 5 dollars a gallon. So far, I have found 2 potentially promising mixtures in various patents and have begun testing them. Polyethylene Oxide Starch The polyethylene oxide based quenchant is simply a solution of high molecular weight polyethylene glycol in water. The stuff is pretty easy to find and considering the very low concentrations needed according to the patent, it's virtually free. This link has a pretty good summary of the stuff, and where to get it. As far as the mixing the quenchant itself, I am using 2.8 grams of J-lube per gallon, or .7 grams of ~2 million molecular weight PO per gallon (J-lube is 75 percent sugar, as a dispersant). It can be very tricky to mix without clumps, so I recommend adding the PO to a smaller quantity of boiling water and stirring. Because PO is insoluble in boiling water, it mixes easily without clumping. It's also very easy to use too much PO- around 1.5 grams per gallon will make it similar to canola, and anything over 2 grams will fail to harden w-2. I have testing this one the most, and have successfully quenched several w-2 blades in it with no problems at all. One of them had a very dramatic spine to edge taper as well, going from .25 to .02 over about an inch. During the quench, there is no noise or boiling at all. There is a vapor phase which quickly shifts to a calm boiling phase where the steel seems to be coated in tiny vibrating dots. It almost looks like static on an old CRT tv, except the dots are very, very small and consistent over the whole surface. There is no effect on the surface of the quenchant, unlike the upwelling you generally see with water. I have a old Leco hardness tester that is not calibrated at all, so all I can say is that the PO/water quench gets the w-2 harder than canola, and what seems to be a tiny bit less than brine. As for the second starch patent, I have done less testing with it, but it seems even more promising. I use laundry starch to make a 1.5 percent solution in water. It seems to have very little vapor phase at all, going straight to an odd looking nucleate boiling stage where the steel is surrounded in a dense misty cloud without any large bubbles. This mist will spread out quite a bit, completely obscuring the submerged steel and rendering the quenchant opaque after just a few seconds. After the quench, the metal is actually coated in a very adherent layer of starchy plastic like stuff that might be responsible for the reduced cooling speed after the initial boiling phase. It has an odd interaction with clay, though. A thin clay wash on any part of the steel will dramatically slow the cooling rate, so much so that w-2 under any thickness of clay will not completely harden. I will continue to perform tests and post results as I have time. Currently, I am casting two high temperature thermocouples into a wedge shaped chuck of nickel aluminum bronze. I intend to record the temperature vs time curves from this with an arduino and hopefully I can get some real data. I would rather use cast iron because of thermal conductivity issues, but I don't have the setup for that yet.