Latticino

Not sure what your issue is with interpreting the Wiki page as regards the style of tanto you are looking to make. To me it looks like all the info is there for you. If you are having trouble with the proportions, you can always use the Xerox trick: Print the image of the blade profile then use a Xerox machine to scale it up or down till it matches the general length and width listed on the Wiki page. The convex portion of the blade crossection is generally only roughly forged then ground to final shape, as far as I know. Slack belt on a grinder, or resilient backed hand sanding "platen" will get you that shape fairly easily. Of course that is trusting what you see on Wikipedia. Going to a source of an actual blade, as Thomas suggested is much better. If you are planning on forging an effective blade you will want to make sure that you use high carbon (tool or spring) steel, not just some random scrap. Starting your forging trying to make a tanto is pretty ambitious. Might make sense to try to pick up some basic forging skills first. You will also need to learn a lot about heat treatment and blade grinding.

Well done for your first forging, particularly forging down what looks like either 3/4" or 1" bar stock. Couple of suggestions for future improvement, if you plan on making more knives: Work on your hammer and fire control to minimize scale formation and hammer head marks in the final product. Steel seems to show some signs of being overheated and burning. Be careful as the blank gets thinner, it will heat much more rapidly. Use high carbon (tool or spring steel) for making knives. The heat treating process is really the heart of making a good functioning blade, secondary only to grinding the correct geometry (which is actually where you have done the best in this first effort: decent first full grind) Plan out what you mean to forge before starting. Looks like you are somewhere in between a full and hidden tang with this one. Forging the tang of your blade is one of the bigger advantages of forging a knife rather than just using stock removal. Heat treatment must be done before riveting the handle in place. Get a heavy duty butcher block style wire brush and use it to help with scale buildup and final finish Take a bladesmithing class to accelerate your learning process. Get and read a couple of the better knife forging books for additional info (Jim Hrisoulas, Steve Sells...).

Love the bench, very clean design and assembly, but am a little confused. Looking at it I see a total of 5 bends (one which might have been able to do cold with the right equipment and the others with a torch) and two smaller (length wise) scrolls. Yet you say you used 210 lbs. of coal, what am I missing?

Don't know anything about the CDBA, but as a member I can recommend going to the NYSDB meetings if you are able to get there.

Recommend you go to the NEB meet at Ashokan. Great place to meet other smiths and they have a decent tailgate section. Last year someone brought in an, admittedly rough, 115# anvil and let it go for $125, if I remember correctly. Would have been a good starter for sure. Otherwise there are plenty of make do alternatives, depending on what you plan on forging.

Don't get me wrong, you did great for a first forge weld. Was just trying to help with your next one.

Extremely nice job. I have a similar one that I inherited from my father in law that I use for jewelry projects, though mine has a hardy hole. Might want to put in a prichel hole at least. It also looks like you may have welded on a top plate. If you did, was it a full penetration weld? What kind of steel did you use for the top plate? How did you heat treat it?

Looks like you got a forge weld, but would have to grind or do a peel test to be sure. Cold shunts at the tips of each bar most likely due to lack of scarf before assembly. "Tear" at location of weld can be due to forging the welded area at too low a temperature. If your hammering will put a stress on the welded joint (i.e. forging in the orientation that is 90 degrees rotated from the forging you did to initially bond the surfaces) it is recommended that you keep the stock at close to welding temperatures until the weld is completely set (and probably thereafter for that matter...).

Looks like a winner to me. Hard to tell from the photos, but do you have a full circumferential weld at the outlet fitting (concentric pipe fitting welded to the discharge side of the mixing chamber)? If you don't, I would highly recommend you complete the weld in that area. I always prefer to have bubble tight joints for piping that has either gas or a gas air mixture. You don't want fuel mixture leaks adjacent to your forge skin. I would be interested to know where your gas orifice tip is located verses the concentric reducer at the entrance to the mixing chamber. Try it inside a forge and see how it performs.

Yes the real world is more complicated than this, mostly because of friction and boundary effects inside these nozzles and at their exit. The boundary layer adjacent to the walls of a pipe can have a very significant effect on how much fluid flows through that pipe as well as the local velocity of the jet at the exit (many smaller pipes is not directly equal to one larger one as regards fluid flow given the same upstream pressure). You didn't think the gas/air mixture inside the burner was flowing at a constant velocity at each crossection did you? This doesn't even include issues with turbulent verses laminar flow (note I'm not saying that the mixture flow inside the pipe is either, haven't done the Reynold's number calcs. but it does make a significant difference) and the end effects of a jet exiting the orifice itself. Personally I think that the turbulating end effects may be a big part of why the ribbon burners slow the flow down so abruptly and consequently work well, but I haven't done any of the analysis, so that is just speculation.

Short answer: No Long answer: Residential natural gas is typically at a MUCH lower pressure than what you use from your propane tank (1/4 psi verses up to 30 psi). If you have a Naturally aspirated (ventauri) burner the air is entrained by the gas escaping through an orifice at high velocity. That velocity is proportional to the upstream gas pressure. Lower pressure means lower amount of air entrained (not to mention less gas as well). This will lead to a malfunctioning burner. If you are using a forced air burner (with a blower) there is a chance that you can just replace your burner orifice with a larger one and get it to work. Orifice size is critical, and expect to need a much larger natural gas line than the propane line (for the reason listed above). See that Thomas has beaten me to the punch this time. As far as I can quickly read, his recommendations are correct, as usual.

That is how I have done it in the past. I suppose you could try to assemble it on the knife while putting on the scales, but I think that would be a bear to align, not to mention drilling the rivet holes.

Sounds to me as if he is looking for a small manufacturing facility, not a one person shop (unless he is just trying to scam you out of a prototype or two - how reputable is this guy?). Ask yourself this: If I get an order for several hundred of these will I end up hating blacksmithing after I'm done? Do I have the equipment, or am I willing to purchase it and set it up on speculation, to go into limited production (and how does that coordinate with the price point for each item)? If it were me I would likely want at least a hydraulic press for the punch and tapered swage, a big belt grinder to clean up the edges quickly, and possibly a fly press for the subtle curvature. How precise will the multiple items have to be to match the design and how good are you at working to spec? Is he going to accept handcrafted variation or will he be looking for a more "machine" grade set of multiples? What about product liability?

I haven't done a ton of welding cable, and hopefully someone with more experience than I have will chime in, but I've found that using a half round crossection bottom fuller or swageblock half round channel to forge into helps with welding cable quite a bit. Also I would suggest using your twisting wrench to twist the cable tighter before welding the center section. What has worked for me is forge welding the two ends, heating to red and wire brushing and fluxing liberally, then heating again and twisting tightly. Reflux and only then I go for my forge weld of a couple of inches at a time. Probably go faster with a press, but all I have is a hand hammer and treadle hammer at this point.

Yes that is the intent of the clay. Did that when I had a cheap source. No I don't believe that Casto lite is considered rammable.

Well I was not going to add any comments to this discussion, but after reviewing rookieironman's previous posts I guess I have to. In one of them I attempted to assist him in his design for his first gas forge (along with several others). While I would never promote myself as an expert in smithing, I do have a fair grounding in gas forge design, and in particular with use of forced air burners (P.E. specializing in HVAC design with years of experience designing, building and using forced air burners, both for off hand glass blowing and for the last couple of years for ironworking). I find his continued negative feedback for folks donating their time to try to help him inappropriate. I have a very, very short list of "ignored" members. He has now joined it.

Not going to review or go into the detail you possibly want but there are couple procedural issues that you might want to address: Don't quench spine first. You want the edge to get cooled immediately and quickly (you have only a matter of seconds before the thin edge cools too slowly past the nose). Room temperature is only acceptable if you are using quench oil formulated for that temperature. If you are using vegetable oil you should preheat the oil to at least 130 deg. F If not differentially heat treating get the whole blade into the quench as quickly as possible. Grind blade with consistent thickness and tapers to minimize warping Agitation in the quench should be longitudinally with the blade axis (not side to side). I believe that this is the root for the superstition that quenching in a north/south orientation prevents warpage. You agitate in a north south direction based on the "compass" direction the blade enters the quench and don't change that orientation by moving it from side to side.. Not sure what you mean by a stress relief cycle. As far as I know the normalization addresses this. off site link removed because that information there is already posted here

Not sure about additional stress in the steel, but depending on how quickly you get back up to critical temperature and how long it is held there you will certainly get more decarb...

I don't know, looks like an "8" to me in the photo (80 lbs.), which would certainly be a more common size. Assuming good rebound, in that pristine condition, a desirable manufacturer and with a custom stand I think you did just fine as regards the price.

I'm not completely sure of the logic behind multiple quenches, but preheating of your quench oil is important to reduce it's viscosity and get a better quench (unless you are using commercial quenching oil like Parks which does not need preheating). One of the best sources for knifemaking metallurgy is Kevin Cashen. He has been kind enough to post some great information. I strongly recommend review of this info (and you will note that his heat treatment procedure for 5160 is a single quench in oil, not water). This process has worked well for me, though I have also done a 5160 blade or two with an edge quench using an oil/paraffin mix and a torch to both heat the edge for quenching and selectively temper afterwards. I suspect that your blade surface cracking was from the overly aggressive water quench. The original break was most likely from trying to bend a fully hardened blade. Even after tempering that is a somewhat questionable practice (which is why I have so many blades with slight warps in them I guess, but I'm still learning). You can do a interrupted quench and attempt to straighten during that time, but that is a bit of an art, or jig your blade with clamps and spare stock to attempt to reduce the bend during the second tempering cycle. Torch tempering the spine, as indicated above, is a great technique, but does not allow for easy warp reduction. I suspect that using the clamped heated stock for tempering may work better.

The PID controller (Proportional, Integral, Derivative feedback loops from the differential between measured temperatures and setpoint) appears to have more capability than you need if you are only looking for a pyrometer type readout for forge interior temperature. The PID controller will also give you outputs that can control things like Solid State relays, contactors, SCR and the like to modulate, or turn on and off, a power source for heating the chamber the sensor is measuring. If you only want a readout a digital temperature indicator will be enough (though if the controller is cheaper or more available it will certainly also give a readout). One thing to be cautious about is that the normal type K thermocouple is not really rated for the above 2300 deg. F and potentially caustic (if using flux) environment of a typical forge. You really should use a type R or S, but they are prohibitively expensive. If you must use a type K, I recommend getting the thickest thermocouple you can reasonably afford and using a ceramic sheath (like you have listed). You will also need type K thermocouple wire to go between the probe and controller/meter. If you use normal wire you will throw off the reading. Be careful to follow the instructions regarding the thermocouple wire as the two wire materials inside the shield are different and need to be hooked to the correct terminals on the thermocouple. Not really enough information to evaluate whether the switch will suffice to turn on your controller, but I would have to say it is likely that it will work fine.

Don't know about that, but the one I visited in Rochester, NY (a private residence) was aesthetically pleasing, but a bit disproportionate for someone my size. If I recall correctly hallways were narrow, built-ins were low, and the Wright chairs were extremely uncomfortable.

Nope, actually was referring to a catenary. Just imagine a tarp loosely hanging in a curve between two fixed edges (like two parallel table tops for example. The refractory material is initially coated onto the tarp, then the tarp is raised from both ends carefully up into place. If the refractory is the right consistency it will form into a nice, strong upside down arch. Never done this myself as I made an arch form that I coated with a layer of clay instead, but theoretically it should work. All about timing and correct mixture consistency. Of course I've also done an annulus, in my case using vinyl flooring (as I've mentioned before). That will also work, but will need to be packed carefully from the top of the annulus. I really like your method of compressing the wool for insertion into the interstitial space. Very clever. I usually just seal the blanket and cast the refractory right over it. May have to try your technique next time I reline.

2" thickness 8# density 2600 degree insulating blanket, colloidal silica rigidizer, 1/2-1" thickness Kastolite 30 on the walls, 1/2" Mizzou on floor and opposite burner port. Of course you could do something else entirely if you don't want to use a forge the way I do. Door design is critical. No idea if your homemade burner will perform in the size forge you outline. Good rule of thumb seems to be a 3/4" NA propane burner is good for up to 300 cubic inches of interior volume or so, but what you believe is a "good flame" may not be. No your homemade refractory will not work if you are looking for thermal efficiency and longevity. Yes this has been answered many times, please read back in the gas forge forum for more detail.

Not to mention use of bent sheet metal covered with clay, carved sacrificial polystyrene foam to be "melted out" using a solvent, suspended heavy duty plastic sheeting to form a catenary to pack refractory onto... Lots of ways to skin that cat. Sorry no in process photos or step by step procedure. Why not try a couple of options and post your own?