Latticino

Hard to say. Certainly looks promising, but output is directly related to impeller RPM and motor size. My gut says using a 1/2 HP motor at an RPM just below blade and bearing allowables should be enough, but it is difficult to predict without knowing details of your piping design and performing tests on your custom ribbon burner. Note: I am not offering to perform this analysis.

Peters Valley School of Craft is relatively nearby for you and a great place to take classes. Strongly recommend taking a class BEFORE making any other investments. If I recall they don't have a lot of gas forges there, but working coal is great training as well.

Also, try to avoid hitting that protective castable with large Damascus billets and breaking off a section like I did last weekend... I need to take my own advice and stick to casting refractories at 3/4" minimum thickness (or just get more careful, but that was the largest billet I've attempted in my home forge: 6" x 2" x 1.5" - only around 5.5 lbs; but it felt like a lot more, particularly when drawn out to 27" length).

Lovely work. That's quite a good size chef's knife.

Keep the hard brick. They make fairly good doors. Soft brick does have a tendency to crack and break after repeated heating and cooling. Consider designing your shell to allow some compression. Note: when it finally gets hot any gaps in your insulation will really show up in the metal skin.

Actually the way I calculated it I included extra for the top and bottom disks, which I had already included in the two cylinders. So volume needed is just 1869.5-1296= 573 cubic inches (0.332 cubic ft), or 30 lbs. Use the extra for casting doors (you will thank me). Weld up simple frames and cast them at the same time. Frosty is correct about the need to tamp down the castable in between the forms. I usually cast lids separately so I can open things back up to reline. Bring your door opening proud of the steel liner and you won't have problems with the dragon's breath overheating that. Also cast your burner port in place. Good luck.

So lets assume a simple can shape with closed top and bottom. This will be the approximation for the amount of castable needed. If you have a 2" thickness of insulation all the way around the outside of the can will be approximately 18" tall and with a 11.5" diameter. If you go with the 3/4" thickness I would recommend (so you can do a much simpler casting with inner and outer cylindrical forms) the inside of the can is 16.5" tall and 10" in diameter. The volume of castable needed is just the outer cylinder volume less the inner cylinder's volume, with the two end caps added. Outer cylinder is 1869.5 cubic inches and the inner one is 1296 cubic inches. End caps are a nominal 11.5" diameter and 3/4" thick (78 cubic inches each). 1869.5-1296+ (2x 78)= 729.5 cubic inches. 729.5 cubic inches is only 0.42 cubic feet. at 92 lbs/CF you only need 39 lbs of castable. I believe you can purchase this castable in 50 lb bags, so that is what I would do. I got mine from an industrial insulation supplier nearby. Maybe you will be as lucky, or you could always take a road trip to one of their sites: https://forum.brickwoodovens.com/t/harbisonwalker-locations-global-sourcing-centers/1122

May want to amend that. Looks like kiln shelves have changed a bit since my ceramics days 30+ years back. Silicon Carbide are still the same, but what they are calling "high alumina" is apparently not always the older bright white I remember. Now they look a lot like mullite/corderite, so much so that I doubt that it has the percentage alumina that I would recommend (the true high alumina shelves are still out there, but buyer beware). These days I don't trust suppliers and would prefer to cast my own 97% high alumina refractory bases using material like Greencast 97 for very good flux resistance.

I vote for wide side on floor, for stability.

Fairly easy to identify. For typical pottery kiln shelves: Silicon Carbide shelves: Black/Grey, heavy weight, medium coarse "end grain" and surface Corderite shelves: light yellow/tan, relatively lighter weight, very smooth "end grain" and surface High Alumina shelves: bright white, medium weight, medium coarse "end grain" and surface Most will be corderite, as that is the budget alternative.

I've always understood it to mean: not according to the original plan, typically in a wild and unexpected fashion. As in: "I expected to get there at 9 PM, but it has all gone catawampus". Of course I'm hardly a southerner, so I could be way off base.

My process with cable is as follows: Select the right cable stock (3/4-1 1/2" overall diameter for me) elevator or crane cable seem to work well. Not all cable is created equal. In addition to avoiding galvanized, avoid cable with a non-metal core. Soak greasy cable in kerosene overnight. Note: lots of folks prefer to burn off the oil and grease, but I feel it leaves behind contaminants. MIG weld ends securely. SS hose clamps might do in a pinch, but will make the next task harder. Heat only the end 2" and forge weld about an inch of that. Liberal use of flux helps with forging cable, so a coal forge is preferable as it is less likely to get damaged. You also can better concentrate a hot flame. Repeat on the opposite side of the cable. Can untwist a bit and tap stock and brush with wire brush to remove any debris, but not always needed. Take a long heat and twist tightly. Repeat till twist is almost circumferential, heating to hotter heat each time and brushing and fluxing between heats. Last twist should be as close as possible to welding temperature and should start to weld the billet. Heat about a 4" section to welding heat and lightly hammer into a v or half circle bottom swage. This helps compress the cable better. Rotate the cable to twist it tighter while you are hammering. Once the cable feels solid repeat a welding pass with heavier blows. Flux regularly. Move heat down the billet and continue the weld until complete.

It all depends on what kind of things you are going to be forging. I might be able to make a dozen 3/8" tapered S-hooks with a couple of handfuls of coal (I have large hands...), but for making a large forge welded axe head I need a deep hot fire for hours. I might use a 50 lb bag almost completely for one large axe head.

I am not familiar with that particular castable refractory mixture (hopefully it is a castable insulating refractory like Kastolite 30, not just a castable refractory like Mizzou), but it shouldn't be necessary to mortar the bricks together before casting. You may want to include a sacrificial layer of wax paper on top of the bricks to keep the castable drying evenly, if you are planning on casting the crown in place. Most castables like to be kept fairly moist while they are setting. Rebar hangers or wire shouldn't be required in the castable floor either. The arched crown may benefit from some form of reinforcement, though any part of it that gets exposed to the forge atmosphere will scale away pretty quickly. I have used stainless needles available from refractory suppliers for this purpose in the past, which can certainly help with the fairly common cracking that you can experience as the forge goes through repeated thermal cycling. They are absolutely NO fun whatsoever to mix into the dry material. The other recommendation I have for you is to modify your frame so you have some kind of compression member holding the bricks in place. Angle with threaded rod is popular. The lightweight bricks are pretty friable and become more brittle over time. As I understand it, with your current design you don't have to worry much about the brick cracking, but you certainly don't want pieces falling off the perimeter. As I've stated in the past, I have a theory that a burner block with long refractory outlets is more likely to suffer from preignition than one with shorter tubes, but I haven't had a chance to really study it.

That should do it. Nice job pulling down the heel as well. Look forward to the finished product.

Certainly looks like wrought to me. You did a fine job keeping the HC centered, at least in the photos. Can be more difficult once forged to shape. I've done a handful of blades with this kind of combination, and the wrought moves so much faster than the HC it can be a challenge to forge accurately. If you forged close to final shape and thickness with forged bevels you should have enough cladding to show up. Can be a real test of your forging skills. Check out Nick Rossi's videos on forging San Mai wrought knives for good info. I don't do a full perimeter weld prior to the initial forge weld, but if you have clean surfaces it can't hurt and will eliminate the need for flux. Be careful when quenching. The different thermal expansion between the hardened steel and wrought can rip your billet apart right down the spine. Careful normalizing and stress relief before hardening and a slight bevel at the spine to reduce the thickness of the cladding seems to help. Also make sure you get the blade into tempering as soon as it cools to a point where you have martensite conversion.

Not to be "that guy", but you really might want to consider encouraging safety glasses while in the shop. After all, he won't be 8' away from the business end of the stock during the entire process. It really sucks getting a flake of scale dremeled out of your cornea.

I wouldn't use that type of fan for a forge blower unless I had no other choice. That fan is optimized for high airflow at relatively low external static pressure (probably on the order of 0.1 inch WG). You want the opposite for a forced air burner fan. If I had to use it I would construct a shroud on the fan outlet that transitions from the 1' x 1' size down to 2" diameter at a maximum of a 30 degree angle from horizontal (something like below, but much longer). I would minimize the duct length at the 2" size and no use elbows unless absolutely necessary. Honestly, for the effort involved, you are better off finding a better option.

Assuming you already have a hardy hole you plan on using the bick in, you source a piece of medium carbon steel (I used 4140 for one and an old jackhammer bit for another. The latter comes with an already forged swell that can work as a seat - see below) that either has a large enough crossection to forge down to fit your hardy (or can be upset to be large enough first). Isolate the mass for the tennon and forge it to fit that square opening. Then reheat that area and forge on top of the stock to create a seat for the bick on top of the receiver. You can also arc or forge weld a collar at that point to build up some mass for a more secure shelf. Then it is just a matter of forging a long taper of the crossection you want and bending it over to the final configuration.

Well, at least the interior of the tuyere... The external surface can get hotter, but since metal is such a great conductor of heat, not all that much hotter unless a steam jacket gets formed at the interior interface of the tuyere and cooling fluid. Looks like a good size tank. Keep it filled with water, and raise up the bed of your forge fill (as others have suggested) and you should be OK. Hopefully the tuyere was fabricated from at least 1/2" thick stock and the exterior pitches down slightly towards the outlet to allow the proper circulation of cooling fluid (my theoretical optimal design for a sideblast tuyere would have the exterior designed as an offset reducer with the flat side down and set horizontal. The inner tube would be parallel to that horizontal bottom "skin", and the whole thing made from wrought iron to stand up better to both the potential rust and heat from the forge).

The water is supposed to get hot. How large is your bosh tank? How is it configured?

As JHCC noted, a high speed inlet very close to the source of the fumes will capture the adjacent fumes. The larger size hood above the source of hot fumes will both capture the fumes and the environmental air from the sides of the hood. If the fumes happen to be rising at a higher velocity than at the capture zone at the face of the hood, they can "hit" that lower velocity section and create turbulence which can lead to the fumes spilling out past the hood. If you look at it from a fluid dynamics standpoint, there is a characteristic flue velocity that will be created by the buoyancy of the lighter hot gasses inside the flue. The hotter the gasses, the potentially higher the velocity (Note: as previously mentioned in other threads, a typical capture velocity for the face of an overhead hood is on the order of 100 ft/min). If you induce significant room air into the flue, you cool those gasses by mixing. The volume flowrate is directly related to this "chimney effect". If the flue stack geometry is the same for an overhead hood and a sidedraft hood the hotter gasses from the latter will pull in more of the fumes you want to extract, and the proximity ensures that. It is not at all uncommon to see the fire at the top of your coal pile to get sucked horizontally by the induced draft.

Yes, I have a HVAC Engineering background, and yes Steve, Goods and JHCC are giving good advise (as usual). Note that after the reduced size entry opening the flue duct should be full size for the entire length to attempt to minimize duct friction which will reduce your flow velocity. Also: The height of the stack is the driver for the exhaust. Within practical limits the taller the better Try to minimize the number of elbows in the line. If you must have them use 45 degree elbows if possible, or at worst long sweep elbows with smooth interiors (pleated elbows of flexible material are the worst option) Check your building code for details on penetration of structure and required height above adjacent roof pitches as well as termination proximity to operable doors and windows. Make sure you have adequate make up air for your exhaust. If the air can't enter your forge the combustion gasses can't be exhausted.

Think carefully about how you are going to support this (including from wind loads). Also keep the duct at least 18" from any combustible structural elements. You may have issues with the fumes spilling past the 12" opening. That is one of the advantages of the side draft hood. A smaller opening can be set very close to the fire, so capture is very effective.

If your wife also has some grog left over from her ceramics efforts I would mix a very generous amount into the clay as well. This will help with the inevitable shrinkage you are going to see when the clay dries. As Frosty noted, try to put the clay in as dry as possible, then let it dry completely before firing your forge.