Latticino

I believe that Tom Latane has forged a bench-mounted blacksmith's vise in "modern" times . Even taught a class in making them, if I remember correctly (though the students reportedly didn't finish during the week long session). Not sure what he did for the screw and screw box. Of course since it is Tom, it is chased and filed within an inch of it's life: I think he may have also done up a full sized post vise as well, but I don't know if it was from raw stock or he "just" filed and chased an existing one.

Please recall that it is also possible to have too large a burner for the forge chamber size. Each burner has a characteristic forge volume as well as flame length for a fully developed flame to burn properly. If your chamber size is too small you will have a lot of difficulty keeping any flame burning inside the forge. If the flame path is overly restricted, too short, you will have a flame that directly impinges on the forge wall to the extent that it does not burn as efficiently and you will see a dark circle on the wall opposite the burner in the center of the heated area.

That's quite low pressure for propane. I use around 7" WG Natural gas in my forced air burner and I have a 1" line leading up to it. Forge size is approximately 6.5" diameter by 14" length (around 465 cubic inches interior). Gas rated solenoid valves can be pretty expensive, but you can find them cheaper than $100+. If you drop the size down, or go with a lower voltage valve and a relay/transformer rather than line voltage you may be able to get them cheaper, or steal one from a broken furnace (as was suggested). YOu may be able to drop the size down if you put your safety valve in the higher pressure location (before the drop to 11" WC)

The old Johnson gas forges with the metal ribbon burners were extremely long (over 14" for sure). Been over 30 years since I used one, so can't really remember too much about it, but a lot were sold so I guess they worked. The ones I saw used natural gas and I think some kind of slide gate for closing off outlet holes when not in use. Memory a bit fuzzy from back that far though. Not even with the same burner assembly given the equation for pressure and fluid velocity (which is directly proportional to flowrate in a fixed diameter pipe/duct) has a squared factor, and that isn't even accounting for orifice conditions.

B for the win, as far as I'm concerned. Cutting the rectangle into the forge skin is the same no matter which option you choose. Cutting the frax blanket is super easy with a very sharp thin knife (I use a fillet knife). Even casting the interior is pretty easy if you put a form in first. If you already have your ribbon burner, just wrap it in plastic and put it in place further into the forge temporarily while you cast the interior. If you need to tweak you can always rasp the Kastolite a bit before it gets fired. Of course the ribbon burner should have a shorter flame, so all of the options should be acceptable regarding flame impingement on work, depending on what you decide to forge. The real question is how well you can distribute the flame/gas mixture over the full 18" (you will need a fairly advanced mixing block design as well as creative baffles IMHO) and just how much propane you will need to use to keep the system from backfiring. I assume you are going with a forced air system? When finished you don't want the ribbon burner to project into the forge that far for any options. I personally like the face of the burner to align with the outer edge of the castable and let the castable act as a bit of an integral flare. Not going to debate you on the forge size. I think Albert Paley's was almost that big, and he ran propylene/air (and a Nazel B6) if I remember correctly.

That's a lovely pattern for a hammer. I don't know squat about farrier work (other than it involves working with these massive beasts that I certainly don't trust), but I wouldn't mind trying my hand at forging one. The set down for the hammer handle socket is particularly nice, as is the subtle cant of the hammer head.

Could be any of these I guess: https://acronyms.thefreedictionary.com/BIU I'm partial to "Beat It Up"

My condolences Steve. My father passed just last year from the same thing. Tough on everyone, hope you and yours can get past it.

Make sure you hold the body tightly together in a vise while you are drifting. The front edge of the eye peels easily. If at all possible, use your axe drift as a mandrel as much as possible.

The anvil face will still be harder than red hot steel, so certainly work can be done on it. Heavy sledge work may deform it earlier than a hardened face, and mis-hits will likely leave marks on the surface. The real issue I've seen with welded face anvils that were not correctly heat treated during and afterwards is that more often than not the welding is done on the anvil edges that have been damaged. The heat affected zone from these "repair" welds end up being brittle and can crack away removing even more of the edge than before the weld was made. On the other hand I've seen weld repairs to the inner face of a preheated anvil (from gouges left by a cutting torch) hold up quite well (though the hardness in that particular area was a little affected). Good luck whatever you decide.

All depends on what kind of layering you mean. Full multiple layers in a pattern welded billet may not give you a blade with a good hardenable edge, if you get a localized concentration of wrought. There may not be appreciable contrast between the two materials on etching, though I suspect there will be. A Gomai, Sanmai, or even Nimai construction with the clip in the center (or on the edge in Nimai) will likely be more successful, but you will have to watch carefully for warping. Some of the coarser wrought leaves a very active surface after etching. This is a wrought/1075 Sanmai kitchen knife I forged for my father:

Well, traditionally smiths were tasked with welding new HC bits into, or onto, axes where long term use had ground away the originals, so you would be in good company if you go for a restoration. The real key is deciding how good you are at forge welding. It certainly is possible to forge weld on a new poll, but it won't be the easiest weld to do and will most likely distort the eye quite a bit. You will need a proper drift or mandrel to reshape it. Otherwise Owen's suggestion is a good one if you just want to get to using it soon. Just make sure to keep the bit cool enough so it doesn't get over tempered. I don't know how things are over in Finland, but in my experience, unless you don't put a value on your time, you would be hard pressed to forge up a larger axe for less cost than buying a commercial one. Manufacturer's have the economy of scale working for them. That being said, I enjoy forging axes, so I don't count the cost.

That's when you switch to using a drill... You had plenty of width and didn't need to punch. If you do punch there is certainly no need to go above yellow/orange heat for such a thin stock. The real key that beginners struggle with is waiting to let the stock cool enough so that the plug shears cleanly away when back punching after punching the stock on the front "bottoms out" on the anvil. These are great tools. I try to have one with me whenever I do any ornamental smithing. This is a great idea for keeping symmetry and most likely the way I would do it.

Used to do the typical grilled cheese toasting and Saki warming carefully using the heat from my glassblowing pipe warmer or glory hole (for reheating glass, no nastiness here). Each of those closely resembles a gas forge. You want a real wake up call, throw a single Cheeto or Dorito chip into your gas forge once it is hot and stand back. Amazing how much flame will shoot out the front. A good illustration of how much chemical energy these things contain that we scarf down.

Using the unistrut is a fantastic idea. If I ever do a wooden workbench I'm definitely stealing that one.

If you have a shell there is no real reason to butter and rigidize the outside of the first layer of blanket. Strongly recommend that you take into account the openings at each end of your forge and consider a door design early Frosty's standard for his burners, given a well insulated forge enclosure, is approximately 350 cubic inches of volume per 3/4" burner. Do your best to follow the latest version of his burner design exactly (in particular getting the gas orifice centered and using the right type of reducing TEE. I'm still not a real fan of the trimming the MIG tip to tune the burner strategy, but it does seem to work for most folks provided care is taken.

Need more info to begin to evaluate. 40 mm of what kind of insulation (and how was it installed)? 50 mm of what kind of castable? Any thermal bridges to the skin, or is it fully lined with insulation and the cast layer not touching the skin at all? How are your doors designed (when the exhaust heat exits, does it pass over the skin of the forge)? Have you thoroughly baked your castable and "buttered" insulation (moisture boiling off will steam heat your skin right up to 100 deg C)?

That is a good point Thomas. What I was really trying to say is that the forging part of knifemaking is only the tip of the iceberg. I guess I've been forging high carbon steel into blades for so long now that I've kind of forgotten the temperature control and extra effort required to forge it. I do agree that knives are not a rank beginner project for a self trained smith, but the actual forging process for a simple knife is only a couple of tapers and simple offsets. I've taught it to first time smiths more than once, though I always prefer if they have already taken a basic class working in mild steel making hooks and the like first.

Welcome to the site. Definitely take a class or two first. Many places are reopening on a reduced load basis with distancing and masks, so you should be able to find one. The bulk of the forges I've seen on e-bay are not worth purchasing, but with limited tools and knowledge of how to use them it will be tough to make your own. There are better commercial forges available, but they cost more. Plenty of posts on the forum regarding that. The search function here doesn't work that well, so you have to use an engine like Google and put Iforgeiron in as one of the terms. While knives are relatively simple to rough forge (but harder to "forge to finish", there are some techniques that can help), 80% of the effort in making a knife takes place after you are done forging. Grinding, heat treatment, finishing, putting on a handle, and even sharpening are all skills that you will need to learn before making a good knife. Again there are work arounds, but it isn't Forged in Fire...

Adlai is good people, as they say. I think you will find that a couple of hours with direct instruction will save you months of trial and error. Good decision!

Ummm, there is a bit of a corollary, depending on how you look at it. A larger forge chamber typically has more thermal mass to heat up to the required re-radiative incandescence with are looking for. There is also a pretty direct relationship between the heat loss from your chamber and the surface area of the external skin (though admittedly in a well insulated chamber it most likely pales next to the losses through the heated exhaust gasses and the radiation through the open door). For my axes and hawks I usually use plain old 20 mule team Borax. It sticks to the steel for me just fine at a low red heat, then melts as the stock heats up in the forge forming the barrier to oxidation I am looking for. Other additions, or anhydrous, are also great though. I have used both a version of Alaskan flux and the commercial Black Magic flux and seen improvements.

In the photo the forge doesn't look nearly hot enough for welding. You will likely need doors, at least, and it is hard to tell about your burner design. Where did you get your forge? Also, just to reiterate what I originally said (as well as others following my post): I recommend you grind the steel faces to be welded completely clean, then flux as soon as they get heated to a dull red. Not just before bending, not after bending, just as soon as you heat it past dull red for the first time after you grind it clean. You will likely have to reflux it several times during the bending process, unless you can speed up some and get it bent in one heat. Once the sides are close to each other, try brushing vigorously then squeezing together with a vise. Flux and heat it up to screaming hot in your forge before bringing it to the anvil. Have hammer in hand and tap the joint closed as soon as the steel touches the anvil. Just a few quick taps to set the weld, then back into the forge. Butterfly style axe forging isn't a beginner project, so don't get frustrated. This may take a couple of tries.

Unfortunately it is difficult to give you a good answer without more information about your custom forge burner that we don't know. You piping configuration and burner head characteristics will influence the blower you need in complicated to calculate ways, but easily subject to measurement. Make yourself a U tube manometer (or slant tube) and measure the static pressure downstream of the blower. If you can lay your hands on a pitot-static probe you can even test the active flowrate as well with a duct traverse. Most of the 5 HP Shopvacs I saw were rated to push 60 CFM. Most likely this is against zero static, but possibly including the filter. Your burner assembly and ribbon head will have some friction losses, so if you want to match your existing output, measuring both quantities will help. That being said, I ran one of the small 160 CFM Blacksmith depot blowers in my gas forge and it worked fine for me. I then upped the blower size to a 1/2 HP Dayton radial I had from another project and that works better, but I have a unusual burner system as well. A ShopVac is rarely the right choice for a forge blower IMHO (solid fuel or gas). They run at too high RPM for their bearings and construction, are not rated for continuous usage, and as you say, are bloody loud.

I'm not sure where you are getting this from. Last time I checked the code I didn't see anything specific for coal burning appliances. I also believe that the "acidic" nature of coal smoke only comes into play once the sulfur content of the coal comes into contact with moisture and creates sulfuric acid, but I could be wrong about that. Shouldn't be happening inside your flue in any case.

It is possible you are looking for the wrong thing. Any HVAC sheetmetal fabricator should be able to set you up with either 10" spiral round duct (costly) or 10" round duct with a Pittsburg seam (longitudinal, snaplock seam - relatively cheap). You shouldn't need a Type B, double wall, chimney vent (very expensive) for the exhaust from a forge hood. However, the big issue comes when you are trying to make a penetration to the exterior of your shop. With conventional round ductwork you will need to have something on the order of a 18" separation from any combustible materials. You will need what is known as an engineered thimble for your ceiling, roof or wall penetration (unless your shop is a concrete building or steel Quonset hut. Double wall, insulated duct, can often be purchased only requiring a 1" clearance. I'm in upstate NY and working towards getting my 10" flue installed as well. Once I make arrangements I could try to help you out with the duct, but suspect shipping will be extremely prohibitive. Good luck.