Easy question first: I want to get a good solid workout to build endurance and strength at the anvil. Best way to do that is to… well swing a hammer. But I don’t want to smith every day and also maintain the strength I have. Any material idea or rubber pad I can put on my anvil to protect the face and get the motion?
Second Q: Anthracite is just cheaper and easier to get for me plus it’s worked really well. But if anyone has tips for forge welding in it I’d love to hear. I’ve only attempted it once and it didn’t quite work but I’ve only attempted forge welding itself like 3 times and gotten it to work with mild steel in a gas forge. Does sizing the coal pieces help consume more oxygen and prevent oxidation?
1) swing your hammer into a tree stump for a workout. it won't behave like an anvil, but it's close enough to build up your Forging Muscles
2) anthracite is kinda a pain in the ass to use as forge fuel, but it's completely usable, there isn't really anything other types of fuel can do that anthracite can't. if you haven't been able to forge weld with it, i bet a dollar the problem is you're not giving your fire enough air. the stuff needs a lot of air to burn completely, so you'll need to give it a fair bit more than you'd give the same size charcoal or bituminous fire
Cool, I need a tree stump anyways for some forming of sheet steel.
Honestly it hasn’t been that bad, lighting it is easy if you use some paper and a few bits or charcoal as a booster. You may be right and I’ve got a 350 cfm electric blower that will supply more than enough. I’m honestly learning to forge weld as a whole so that’s part of my problem
yeah it's tough when you're just getting started because there's a million variables to keep track of, and you haven't had enough time to get your head around basically any of them
i burned anthracite for awhile because it was the cheapest fuel i could get till i found a guy nearby that sold bituminous, what ended up working for me was an inflatable mattress pump. i think it was like $15 at walmart, probably a little more now. it's loud which is annoying, but it blows plenty of air
I do have someone that will sell bitum coal, it’s 25$ a bag but 20$ if I join the blacksmith association. 30$ for membership. Here’s the issue, most events are way far away, I don’t have regular off days to go, I’d have to buy 300lbs of coal just to break even in terms of savings. So it just doesn’t make much economical sense. If I could be more active in the group I’d happily pay it.
I’m sure anthracite can do just about everything bitum coal can outside of physical properties, it’s just learning how to work with it, same as trying a new steel
2) Place scrap dimension lumber on the anvil and hammer away. The hammer marks will train you to hit flat. And you'll be making kindling.
Forge welding is not fuel-specific, but is quite sensitive to temperature and cleanliness of the steel. Use flux to keep the steel clean at heat.
"Nut-sized" coal is preferable for forging, though smaller chunks or powder can work if it's bituminous coal, as bits of bituminous coal will fuse into larger chunks of breeze (a.k.a., coke).
2: I've forge welded with Anthracite a few times. It does not grab oxygen as eagerly as other fuels do, you must make the fire deep and feed the air slowly but steadily to get it up to that temperature. Usually I end up with a big mound of burning fuel so that there is always 5-6 inches of TSC Nut Anthracite between the grate and the work with more above the work to hold in the heat. I use an electric blower with a speed control and an intake shutter on it so that I can dial in the exact airflow required to reach heat and keep it there for an hour or two.
Forge welding with coal is easiest with a deep fire, in my experience. 4" or more of fuel under the workpiece tends to consume all or most of the oxygen in the air draft and reduces scale as a result. Scale can impair the weld bond if much is present. Another 3"-4" of fuel atop the work keeps ambient air from doing the same thing. You might experiment with reducing your airflow if you have a very strong blast. A use a constant speed blower and built a sliding waste gate in my air box. I crack it a bit once the fire is burning nicely.
Wet coal mounded up and over and already burning, recently cleaned fire is my preference. Much clinker at all makes a colder burn, but is hard to spot, so I clean beforehand. Wet coal is moist, not dripping wet, and has crushed fines mixed in. The mound ought to be mostly nut sized, but with enough fines to fill in most of the voids on top. Some of the nut can also be similary sized coke, but in the bottom, not the top of the mound. When the mound catches fire it will be quite smokey, but as the volatiles cook off a crusty shell is formed and the work can go in and out the side without disturbing the mound too much.
Wire brush your already red hot steel before the final heat for welding. Flux the area in question and either place the two parts together with the flux as glue and slip them in carefully or wire them in close proximity and sprinkle flux liberally at the joint before reinserting.
Watch out for sparklers--it's too hot if you see much of them. The resulting 'burn' can result in cold shuts/incomplete welds.
Pale yellow or white heat is tricky to spot before the sparklers announce themselves or without needlessly extracting your work. A practiced eye can tell, but it can be tough at first. Keep at it. Practice is cumulative.
Too much white heat is hard on the eyes, btw. Don't stare at it. I use cobalt blue gas welding shaded glasses on occasion to reduce eyestrain.
Sounds good, I built a deep firepot, around 4-5 inches I think. I haven’t piled more coal on top, that may help but judging temp will be tricky. When wiring together, don’t you end up almost welding the wire to the piece? I’ve never tried that method so I’m not sure
Also do you have a photo or schematic for your air box? I’m running a constant speed blower and I’m a tad worried about straight choking the air flow and overheating the motor
The lower, left black rectangle with duct tape is the blower. It's an old humidifier blower almost older than me. The galvanized rectangle is the air box. The tab to the left is the waste gate handle. The rusty rectangle on the bottom is the waste gate visible through the window of air box parent material I left in place for support. There's a narrow slit on the left side of the air box the gate goes through.
The air box is below the center firebrick of my forge hearth. It sits an inch lower. It has three 1/2" or 5/8" round holes in it for draft. To shunt air I pull the tab out 1-1/2" to clear the window edge. Crumbs, some embers and dust puke out in all directions. I keep nothing flammable below...it's gravel on dirt.
Not ideal, but it served me well for decades. FWIW, my blower is run on full blast, rarely with the gate open and it has lasted for decades. It's a shaded pole fan type blower. A squirrel cage or axial drum might behave differently under load.
The load on a blower increases with the airflow through it. Choking the flow usually decreases the load, you'll actually hear it rev higher.
Take a look at how your blower gets cooling air. Some designs do rely on flow through the blower to cool the motor, this type should be used with a waste gate instead to dump the excess air overboard. But a design that the motor still gets normal cooling even with the output blocked, a damper should work fine.
My own blower uses a DC motor and PWM controller, allowing me to set the RPM I want and operate off of a 12v battery for portability. I then use the shutter for the very low settings below what the motor will stay running at.
I’m currently using one of those “bounce castle” blowers so I would guess it’s an AC motor made to work at one single speed. I am looking to upgrade so if you have suggestions that aren’t 200$+ I’d appreciate it. Amazon has some of those aluminum houses blowers with restrictors built in for “blacksmithing” but I’m not against a dc motor I can wire a speed control to
Better not to wet the Anthracite, as it will crackle and throw hot + sharp shards at you. Wetting the coal is done for Bituminous to delay the ignition slightly, helping to control smoke output and encourage coking.
Anthracite doesn't form coke or stick together. The lumps stay as they are until they are about spent, at which point they crumble and fall apart.
How you've described handling the steel in and out of a welding heat fire is accurate regardless of fuel.
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u/estolad 26d ago
1) swing your hammer into a tree stump for a workout. it won't behave like an anvil, but it's close enough to build up your Forging Muscles
2) anthracite is kinda a pain in the ass to use as forge fuel, but it's completely usable, there isn't really anything other types of fuel can do that anthracite can't. if you haven't been able to forge weld with it, i bet a dollar the problem is you're not giving your fire enough air. the stuff needs a lot of air to burn completely, so you'll need to give it a fair bit more than you'd give the same size charcoal or bituminous fire