Latticino

Wishing you and yours all the best Charles. Hopes for a quick recovery and easier times.

Yes I got the 1084 from the NJSB, but am not certain if it is low manganese or not. Just bought it off the back of his truck, and didn't know to ask. I'll try again on my next quench, have a couple of blades approaching that time. I assume you clay coat with Satinite after initial polish to 600 grit, thin wash up to edge proximity, then thicker trails for the "activity"? Can I get away with quench in heated canola, as I do with normal heat treatment, or do I need to get some faster oil? Actually my best success with differential heat treatment was way back in '79 when I was taking a Materials Science class from a very creative professor during intersession. We used premade knife blanks, so I have no idea what steel they were, but did the full polish, clay coat and water quench. The 10" blades hardened extremely well, and bent up just like Japanese swords (I know there is a technical term for that (sori?), but can't recall it just now). I don't remember tempering these at all, but expect they must have auto-tempered to some extent as I still have two of them and have used one quite a bit over the years with no chipping. Wish I had kept with it instead of taking 35 years off, might be a decent bladesmith by now...

Best of luck getting a hamon with 1084. I've been trying to do that periodically with no appreciable success so far. If you get a process that works reliably please post it along with photos of the results, I'd love to get that working.

Good job getting him started so early. My son only helps out when coerced and has no real interest in doing it himself. He is 21 now and has other things on his mind. Nice seeing him with good PPE as well (apron, safety glasses and ear protection). Only suggestion I have is that the tongs look a bit big for him, though he seem to be one handing them pretty well. You might consider having him work with longer stock or at least a tong clip or ring.

Clarification: I design HVAC systems for a living, hoods are a small subset of this. I am not a professional industrial hood designer but have been responsible for designing hoods for anything from Type 1 commercial kitchen operations, BSL 3 capture, and welding operations in my career. There are advantages and disadvantages to each type of hood. I've used both, and correctly designed they both work well. Everything in life is a compromise, you just need to decide what compromises you are willing to accept. The side draft hood has a lot of advantages: It is smaller than a full sized overhead hood so more easily portable. It is typically located closer to the source of heat. Since the temperature differential between the hot fumes rising off the fire and the surrounding air are what drives the exhaust, the closer the better. For equal diameter and height stacks that temperature differential will move more air at higher velocity. It does not obscure the view from above or the sides A couple of disadvantages: Side drafts are not always "self-starting" so to induce the exhaust flow you often will need to start the airflow up the stack by throwing in some burning paper or the like Careful attention to design is required to avoid having the bottom of the hood getting filled up with ash and/or coke pushed in while fire tending or dropping down the stack Optimal design should have a smooth transition to the stack, though it isn't as critical as with an overhead hood Stack support can be more problematic for a freestanding unit as the base of the hood is a lot smaller than a full hood. Because it handles hotter flue gases construction may need to be of thicker material and for a portable forge it may take longer too cool sufficiently to move when finished forging. Overhead hoods have the reflection of those pros and cons, essentially, but there are a couple of caveats: Side skirts will help a lot, and can be designed with a 30-45 degree cut away if necessary. Hood should be kept as low as possible over the fire to avoid inducing more surrounding ambient air. This can be a problem with both seeing your work and banging into the hood. Any crosswinds may exacerbate this. For outside forging attempt to orient your hood in a direction so the closed side is to the apparent wind if possible. Ideal capture velocity is around 100 FPM, ideal stack velocity is in the range of 1,500 - 3,000 FPM which should give an idea of relative cross sectional areas. The heated plume from your forge will also spread out as it rises, so a good idea of how large a fire you are planning will help with your design. As mentioned the transition between the hood opening and stack is somewhat critical. As there isn't the same heat differential driving the exhaust it is more important to have a gradual transition so you minimize your friction losses.

Side screens not only help with crosswinds, as you have noted, but significantly reduce the amount of airflow needed to go up a hood to capture any fumes generated from below it. Has to do with edge effects and containment of plume. Theoretically a hood with good side skirts, if close enough above the fire to capture the plume and having a nice gradual taper to the stack, should capture more heat and fumes than a side sucker with equivalent stack (though the latter work quite well also).

Correct. Good luck, be safe.

Without using CAD, for a shortcut I would suggest taking an image of a scroll you like (like that below that I downloaded) and scaling it up or down to fit your frame width using a Xerox machine. If you measure the original it is pretty easy to figure the scale factor to fit it into a final size. Can even go a little oversized to be able to spring it into place as the others suggest.

Frosty is certainly the expert on his T-burners, and I'm glad that he is helping you tune yours. Needless to say you should never have flames exiting the open sides of the T, if you do the air is moving in the wrong direction overall and backpressure is the likely culprit. I'm not sure if it was mentioned, but in addition to burner outlet placement, door opening size can be a contributor to backpressure problems as well. I've had systems that needed their doors full open while they initially warmed up and then would accept more closed openings once the forge got up to temperature. Weird dynamics. As far as a windscreen goes, my vision of a simple one for these burners is just a coffee tin with a small opening cut in the bottom for the gas fitting to slide through. Assemble it with the open side towards the forge, covering the tee fitting, and the bottom braced against the brass fitting that holds the MIG tip. Provided the annular area left is over two times that of the two openings in the tee that should not restrict airflow, but should block the wind. Of course if you have gates over the tee openings to adjust your air/gas ratio this will be in the way, but could be installed after the overall system is tuned. Will have to try one on the 1/2" Frosty T that I cobbled together for my mini paint can forge (2" frax blanket and refractory cement insulation), though I forge inside most of the time.

Welcome aboard. Don't know what your concerns are. Those both look like fantastic anvils that will be more than adequate for forging knives and small items. The stake anvil is particularly clean and the hardy hole in the "London Pattern" is in a much better location IMHO than the usual heel penetration. Face, edges and horns all look fairly pristine. I'm no collector, so don't much care how old an anvil is, but those look to be great workers and I'd be very pleased to use them.

Frosty, My mistake, don't know where my mind was when I posted that. The fan laws of similarity are quite clear, and it is a cubic relationship. If you reduce the airflow a fan develops (CFM) the brake horsepower the motor uses should go down by the cube of the CFM ratio (would put in the formula, but no time right now). However, the inlet change does effect the fan characteristics, so there we no longer have "similar" fans. The motor speeding up may be evident, depending on what type of motor you use, but it is experiencing less resistance, so may not be drawing more power, even if it is turning faster. That is one worth checking empirically. It is an ammeter to measure the current draw to calculate the power the motor is using for a particular task. The voltage stays essentially the same and the power draw in watts is just the product of that voltage and the current (for single phase, multi phase is more complicated). Typically I use an Amprobe that wraps around one leg of the power to do testing.

Needless to say you don't want to temper the blade any further, you need to heat treat it (including normalizing, quenching and tempering). I can't imagine any way that you can selectively heat treat just the end of the blade without affecting some of the rest of it (even if you are able to heat only one section up to 1450 and quench it without burning the handle, you are still going to get a transition between the two). If you don't want to, or can't, remove the handle and do it properly (as Thomas recommends) you will need to re-profile again and remove the soft tip. This time I would suggest that you stick to hand tools like files and sandpaper to avoid working too fast and heating the metal. Are you sure it was properly heat treated in the first place?

Not to be overly pedantic, but: Air outlet restrictions for the blower will "ride the fan curve" by increasing the system external static pressure (ESP, seriously... that is the acronym). This will increase the load on the motor, though probably not a big issue as far as energy cost goes with these fractional horsepower motors we use in our forges. Slide gate air inlet restriction changes the characteristics of the blower itself (the characteristic fan curve). This will affect how the motor runs in more unpredictable ways, but more often than not will lower the load against the motor, as Frosty noted. On my forge I use air inlet restriction for gross tuning and a butterfly valve on the outlet for fine tuning, but there is no reason to go for both. One last thing you may want to check is the orifice size for the propane jet inside the burner. It is far from critical with a blown burner and good regulator, but if you are having trouble tuning the burner that may be the culprit. Doors are a big help. If it can reach welding temperatures I'd certainly use it just as is for a welding gas forge. With that refractory shell it will be less prone to damage from flux. You can always make a second can with better insulation for more efficient forging later.

Cross post with Frosty. We agree, as usual How much do you want to spend? I like this type for a basic propane tank (preferably with a gage attached) These are available at many locations. URL may not be acceptable here, but google propane regulators and you'll find them: Looks like you already have the fitting to go to the tank, so that will help. If you haven't piped gas lines before, please get help, do some research, use gas pipe tape or dope, and test all your joints. BTW it is hard to tell, but if the tank insulation is just high temp cast refractory this thing may be a bit of a gas hog. See how hot the exterior shell gets when firing up. You may wish to reinsulate.

Not to mention what you are planning on forge welding. If high carbon steel only you need to get up to the high yellow/orange range. If wrought iron you need to be in the white hot range. Low carbon steel somewhere in between. The other side of the equation is how massive your billet will be inside the forge, and how long you will take to heat it up each time. While a light weight fiber blanket forge will get up to temperature quickly, when you put a massive colder billet into it, it will cool it down quite a bit faster than a forge with some thermal mass. Of course the latter forge will take a lot longer to get up to temperature, provided it has the same insulating value in its walls. I assume that you are planning on forge welding up some patterned billets of high carbon and nickel. I'm not the best person to answer that as I have only limited direct experience. Remember that if you plan on using flux on your billets you need to build a forge that can handle more flux contact. It will eat through any soft brick or refractory blanket insulation in a hurry. That is why most folks have a separate forge body for welding verses the one used for forging.

Not completely sure why you think you need more than a 3/4" Venturi burner for a knife making forge. A forge only used for knife making doesn't have to be very large at all. Remember that you can only beat on about 6" of knife length during any heat in any case, and with a pass thru door you can make a pretty long knife in a forge that has a 6" internal diameter and is around a foot long. If you build yourself a 3/4" Frosty T-burner (the parts for which are pretty darn cheap if you already have a ball valve and propane regulator) you should be fine if the forge is properly insulated and has a good door. Needless to say a single, well designed blown burner will also serve such a forge well. If you want to optimize the efficient heating of the blown burner, probably the best avenue for doing this is to build yourself a ribbon burner to get even heating to the walls ASAP so they can reflect the same back onto your stock. While you can combine naturally aspirated (NA) burners with blown burners in a single chamber, it will make tuning the former much more difficult. The NA burner will be very sensitive to whether the blown burner is on and how you deal with your door openings. If the NA burner is idle, and you don't have it's opening into the forge plugged, you will heat that burner up quite a bit since there will be no air going thru it and the blown burner's exhaust gasses will in part be exhausted thru the port. Actually, on reflection, I wonder how forges with multiple NA burners get away with this without overheating their inactive NA burners. Probably not as big an issue since there is less outlet pressure from the burner assembly? In any case, I also would not recommend combining burner types as you are proposing.

Again I have to apologize, I wrote this too fast. Needless to say I meant a capture velocity of 100 feet per minute not CFM.

Apologies if I'm overcomplicating this for you. You can certainly jury rig something together that will work, particularly if you are only using the fan for some kind of boosting of the typical exhaust that you will get anyway due to the chimney effect. I was just trying to help with a design that I would make for myself if I was trying to ensure forced capture of everything generated by the forge. As far as an inline centrifugal fan, with the motor out of the airstream, the unit on the left is an example of that and the one next to it a similar fan with a direct drive motor in the airstream (the reason to keep the motor out of the airstream is to avoid having it damaged by heat or debris : There are any number of suppliers for this kind of equipment. Greenheck and Loren Cook come to mind immediately as reputable manufacturers, but you could always keep an eye out at a liquidator. Other possibilities include upblast rooftop fans, or inline fans with motor in airstream (if you have enough room air induced at the hood to cool the airstream adequately):

I have not specifically power exhausted a forge hood, but I kind of do that sort of design stuff for a living. I have also power exhausted a hood over various glass equipment that essentially acts similarly to a forge in any case. My recommendations for full updraft capture would be to construct a hood that covers the entire heat producing area with approximately a 6" overhang on all sides. A capture velocity of approximately 100 CFM per square foot of hood opening will take care of virtually anything the forge can throw out. Your duct to the fan and building exterior should be sized for between 1,000 and 2,000 feet per minute of air velocity and the fan external static pressure be in the range between 1/2" and 3/4" water gauge (provided your duct routing doesn't go too far or have too many bends). I suggest an inline centrifugal fan with the motor out of the airstream. Make sure you obey any code requirements for the exhaust outlet location from your building and remember that you need to provide a source for makeup air to replace that which is being exhausted. A great sourcebook for additional information is "Industrial Ventilation" (check for copies in your local engineering college library).

There you go. Hot steel=success!

Cool, looking forward to seeing the video. I just finished drilling out a 3.5" thick piece of mild steel for making a striking anvil (of sorts) and have yet to finish same. I'll be going the drill/chisel/file route most likely, as I wouldn't dare try to push around a 65# chunk of hot steel, much less get a drift stuck in same. Wish I had S7, or any kind of high carbon steel for that matter, but since I have no practical way to quench and temper such a large hunk of steel I will have to live with mild steel. Hopefully it will do for the limited number of hardy tools and hammers I plan on making.

Planning on smelting your own steel from raw materials, or are you going to be overly modern and use that high tech purchased stuff? For a beginner I would recommend 1084, after you learn some basic forging skills on alternate non-knife projects. How about charcoal, there were whole communities formed around charcoal making in the past, or were you planning on digging you own coal as well? If we can assume that you just mean that you want to work without electricity or refined heat sources like propane I would recommend the following (which will give you plenty of blood, sweat and tears): Simple charcoal forge and double action bellows like Iron Dwarf suggests. A block anvil of some sort with a couple of tongs and a 2# cross peen hammer. A hacksaw, vise, a handful of files with a file card, container to quench in and oil to quench with, and some sand paper in various grits between 120 and 1200 grits. Get the $50 knife shop book and study it carefully. Then try to take a class in knifemaking from someone who already knows how to do it, unless you really enjoy taking an unusual time learning from your own mistakes.

Matto, That's good advice. Mostly I got carried away trying to make the facets all match and removing any hammer marks. It sure is a lot of work forging the large stuff, especially in high carbon. I do really enjoy making tools though, and this one looks a lot better in person than my poor photos. Once I get the face properly crowned I hope it will move metal like Frosty's friends. Not sure a gas card will do it... He runs out of steam because he isn't really all that interested and starts playing around with my large 15# striking hammer to get extra exercise. Then he gets too worn out to properly strike when I'm ready for him. If I tool up properly I think I can make do with the treadle hammer instead. Thanks for the feedback.

I think what you are looking for is fairly rare in the blacksmith community. My setup is pretty unusual as far as I know. For some good info on "ribbon" burners (or burners with small multiple outlets for the burner head in whatever configuration) I urge you to look at the info on Dudley Giberson's site. He has been at it for quite a few years and knows his stuff as far as the premix with ribbon style burner head systems, and now even has a design specifically for small forges. That one uses propane and a ventauri, but his standard burner design works just fine for natural gas and a blower: http://www.joppaglass.com/burner/coup_mix.html. Note the inline configuration to get the most out of the low pressure squirrel cage blower. I believe that the turbulence and backpressure of the burner head works fine for getting the mixing required without the 9 pipe diameters you mentioned in the above. Please be sure to click on the image for more detail on the burner orifice size and construction. Note that I have no financial connection with Dudley, just know that he is a stand up guy with a great product. This page on his site is also of interest and give some info on the size burner head he recommends for a small forge: http://www.joppaglass.com/new_ideas/forge_page.html. Note in particular the ram-cast burner block he uses for the forge connection to the ribbon burner. I cast a similar one out of Mizzou for my glass furnace and it lasted for over 12 years of virtually constant use. This casting will help protect the burner head as well as the connection to the forge. Again, these are his designs, and could have easily been found online with a simple search. My design is quite a bit different and influenced by my years of researching and building glass furnace burner assemblies.

No ribbon burner yet. Have an old Giberson head that I may try out, if it isn't too badly cracked (high alumina refractory multi port head in a cylindrical configuration, mine is at least 15 years old). I'm currently using a SS flame retention nozzle that came with the burner assembly. If I go up to the Giberson I'll have to cut a larger hole. Mizzou isn't that bad for flux (glass) contact, as long as it isn't swimming in it. I had some on the floor of a pleated frax glory hole (hot glass reheating equipment, don't get the wrong idea ) that I used every day for 12 years and didn't have a melt thru due to glass spalling off puntys. I'm pretty sure molten soda lime silica glass is just as corrosive as molten flux. Floor in my current forge is lined with a thin layer of bubble alumina. You could also use a high alumina hard brick split (Cristalite) but they are pretty expensive (that is what I'm using for the shelf and temporary door outside my forge, but I had them laying around for the last 25 years, so why not). I am familiar with Wayne's excellent resource. May build one of that style burner some day. Industrial mixers are the ticket, if you can source one cheap, like I did. True ventauri inducers and zero pressure regulators for stable mixture proportion over a range of heat output. My old setup even had programmable PID control of temperature with UV sensor on a pilot and high/low fire control.