EricJergensen

Coal forge has IR problems as well, tho the coal on top of the fire makes it less intense generally than propane. I use #3 welding shades when I need to stare in either one and avoid staring when not protected. UV is negligible from coal.

Do you use the far edge much? I'm right against my stand when I'm using the far edge for half-face blows.

I agree with littleblacksmith: the stand puts you too far from the edges of your anvil. If you had a narrower (both dimensions) stand, you'd want to bolt it to the floor or at least a plate.

Consider getting Mark Aspery's 3rd volume: Mastering The Fundamentals Of Traditional Joinery. (Actually, consider getting his whole series.)

The finish grinding of your hammer face may be as much an issue as your technique. Your general purpose hammer should have a slightly convex face with a radiused edge. This slight curve means that the hammer will make a nearly imperceptible divot even when a bit off of a flat blow. The other issue is being able to hit with good alignment. You might try hammering wood for a while. It will leave a very easy to read record of the alignment of each blow. Note that forging generally proceeds from major movement of metal where power is more important than precision to finish work where precision is more important than power. That is, as you approach final form, ease off and focus on precision.

removed: duplicated information already mentioned

You seem to have missed the more typical "bladesmith" models and only looked at the "access" models. The site claims to reach welding temperatures even on the "access" models. I suspect that these have been tested to do exactly that. And, the site notes that the "access" models are for special purposes like sculpture and armor. On the other hand, the "bladesmith" models feature ceramic fiber insulation in addition to the ceramic floor / hearth. Obviously, the enclosed models will use less fuel to maintain heat. I can't answer the OP's question, tho, as I don't have any direct experience.

I prefer to have my 120# fastened. Stand to the floor and anvil to the stand. As an aside, I uploaded a video to YouTube prior to having the stand bolted to the floor. YouTube offered to stabilize the video even tho it was made with a tripod! No such offers since I bolted the stand down.

You are correct: didymium block a very narrow band of light and do not provide meaningful IR protection. They simply make excessive exposure comfortable :-(. I use some 3M flip up #3 welding shades on my safety glasses. They are rated for IR protection. #5 is too much for most blacksmithing purposes. I typically don't use the shades except when forge welding. At other times, I avoid starting into the coal fire (that's surprisingly difficult at first). When I use propane, I flip them down to look into the forge. With coal, I generally count revolutions as I spin my blower to estimate heating so I don't look into the fire much for general heating. With induction heat, I only flip them down for welding heats where I have to really watch the metal. Judging color is really only a big deal in tempering and I assume the IR output at those temperatures is harmless. For forge welding, the real key is looking at the behavior of the scale. Once it melts, you're there. Also, you can compare to the forge (coal or propane) background. The welding shades affect both the stock and the forge so it's an easy comparison. When the stock is the color of the forge, you're there. For coal this is the color of a modest blast and can vary a bit. For propane, you've set your forge to the settings you know reach welding heat so it's pretty accurate.

You're looking at 800 amps probably (the LH-15a does 800 amps). Get the 8mm flare fittings. Your water cooler is probably already lower than your induction heater, but just in case: if your cooler isn't lower than your induction heater, coil change will be a wet mess. P.S. I would expect that any quick release fittings would basically weld themselves together!

One thing to think about is that you are accumulating (to some extent) hot air under the carport. This reduces the heat differential that drives the airflow. If sparks are your main concern, consider fabricating a spark arrestor from metal mesh. Make sure that the arrestor has enough surface area to avoid choking the airflow.

You are both doing the community a big service with your efforts and advice! It's much (and widely) appreciated!

arkie: I'm kinda guessing here, but I think you would get better results if you ran the chimney out and then up outside of your carport even if you didn't get above the peak of the roof. I'm imagining going out the back, not top, of your side draft hood and securing 10 feet (at least) of chimney to one of the uprights. Obviously, I'm imagining that you rotate your forge 90° so the back is to the outside. You could go out the side of your hood if you wanted. Also, 8" is a bit marginal. 10" is better. 12" is probably about as good as good as it gets. After 12", your "returns" from increased diameter is probably negligible.

My clinker breaker is exactly like that. Never used it tho. My clinker never ends up stuck in the slots. When I'm lazy, I sometimes end up with a clinker that is a foamy impression of the bottom 2 inches of my firepot, but still nothing in the slots. I'm guessing that's more a characteristic of the coal I use (which has always been the Saltfork Craftsmen coal).

I have successfully welded a leaf spring of unknown provenance to itself. My conclusion (just a guess really) from that success is that the spring wasn't 5160. It is probably easier to weld 5160 to mild steel than to itself. You could try that just to see what happens. Also, why 5160 to 5160? Wouldn't you use 15n20 or similar for contrast? I'm not a fan of unknown ("junkyard") steels. They cost too much.

The closest coal pile is on the east side of Norman, OK. Probably a 3 hour drive. Coal is $.07 / lb, members only. You'll spend way more on gas than coal no matter how much you get ;-).

Kozzy, With a coil designed to do this, yes, 5 seconds. Using the timers and automatic mode, you could probably dial this in nicely with some trial-and-error. There are three timers which are intended to be used as a heat time, hold time and reload time. As a wild guess, 2-3 s of 800A heating followed by 2-3 s of 400A holding (for a soak, induction is a bit of a surface effect) followed by enough idle time to head and reload. With some trial-and-error, you could find the parameters that hit your forging temp window. This kind of "light industrial" operation is what this kind of heater is designed for. A coil for doing this would probably feature two turns of 6mm tubing with an inner diameter of 1/4". I'd set up some angle iron in a V config to hold the stock and push it into the coil with a fire brick as a stop. I can't imagine you'd need 3-phase to do this. Picture how quickly a 220V welder can heat 1/4" by 3/16". Pretty much instantaneous.

I purchased a LH-15a on ebay. It's not customized for use as a forge. You'll at least want to ask for a horizontal coil arrangement. You should read my Saltfork Craftsmen newsletter article before you go this route (Feb 2016 issue). You might consider buying from Mettle Works. I suspect it's the same unit, but working with someone in the USA that understands using it for Blacksmithing is valuable. In any case, keep in mind that you'll spend a few hundred $US on a cooling solution as well.

IR is more than just tiring on your eyes. IR will damage your eyes. Various IR frequencies damage corneas (cataracts), lenses (worse!) and retinas (yikes!). As noted, didymium does not block IR, but it will make you *feel* comfortable staring into a forge and getting a pretty stout IR dose. I personally use #3 and judge heat against the ambient color of the forge. I'm not really looking at color, just relative intensity. I suspect that a brief look into a forge will not do damage, but it's sometimes hard not to just stare. And, for something like welding heat it's pretty hard to get by with just a glance.

Sunglasses are never okay as PPE. They are not spec'd for impact resistance and they are not spec'd to block IR. Sunglasses are used to deal with glare and other effects from *scattered* sunlight which doesn't really include much IR. However, because they limit your exposer to the visible light that controls iris dilation while *not* limiting the IR, you are likely to let more IR thru to the lens and retina. Cornea damage can occur regardless. Welding shade #3 or #5 glasses are spec'd to block a certain amount of IR. They are intended for looking directly at incandescent light sources that are quite IR intense. Staring into a coal, charcoal or propane forge requires IR protection because they are such light sources. The IR damage does appear to have a threshold effect (from the combination of duration and intensity). That is, less than a certain level causes no damage. Probably staring into a campfire is below threshold. Somewhere between there and a forging heat, you need IR protection. I use #3 clip-ons that I flip down for heating and usually flip up for forging.

Don't start with spikes for tongs if you can help it. Joe was kinda poking fun when he used them. Start with stock long enough that you don't need tongs. 3/4" square stock is easy for a beginner because it helps line everything up. 3/4" round is fine, just not quite to easy on the 90° rotations. A36 is generally just fine. Here in oil country, I made almost all my original tooling (from chisels to tongs) from 5/8" or 3/4" sucker rod. It's cheaper than any other scrap here and generally decent steel. It's borderline for struck tools like chisels, but good enough. It's great for tongs. I still use it for a one-off struck tool that won't see much use. My new tools are generally W1 or H13 depending on usage. I plan to replace W1 with O1 once I run out of W1. So, use sucker rod to learn on (and forever for tongs) if you can get it. Otherwise, 3/4" square A36 is okay for tongs and get some 3/4" (and maybe 1/2") W1 drill rod for struck tools.

Also, look on ebay for "draft inducer" (that's the blower that provides combustion air in your home furnace). I bought one cheap to build a water cooler for my induction heater, but that's another story. Block (partially) the intake to control the draft. Typically a round plate that pivots on one side of the intake and is tight enough to hold position works nicely.

Tony, All matter in the forms you are used to is mostly empty space. Styrofoam is macroscopically empty. Iron crystals are not. You can't fit air into those empty spaces. Air is much too big. It's sub-atomically empty, not macroscopically empty.

Yes, your metal seems to behave like mine. I leave them thin. They're not much north of 1/4", probably 5/16". I use other stock for thicker. Upsetting something like 1/4" is, uhm, very upsetting ;-).

I have made strikers from garage door spring. My junk-yard steel may not match yours. But, what works for me is to heat rather past magnetic and quench in oil. No temper. I have also done water quench, but tended to end up with broken pieces too often. Heating it too hot seems to help. I'm imagining that it encourages grain growth and that is helpful to sparking. If your steel fails Thomas's test, don't bother with my procedure.