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Comment by bcks | Hacker News Reader

Took my daughter to check out a blacksmithing class in Brooklyn and was pleasantly surprised to find there was no open fire at all. The iron and steel are heated by an induction machine. Just use the tongs to hold up your material near the coil and press the pedal and voila, it soon starts to glow red hot. The space is small, maybe 3 students at a time plus a teacher, but it was bright, tidy, and clean. Not at all the dark, sweaty cave of fire and fumes that I'd imagined, and interesting to see tech slightly more modern than fire.

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Cookie-dough coffee can forge*: https://youtu.be/FmEb1YZScxc

DIY induction heater**: https://youtu.be/wKFnk4R54ZQ

* Unsafe because it depends on combustion and creates nanofines/ultrafines

** Unsafe because there's no current limiting, no temperature limiting, no grounding, and no crucible confinement

I'm hesitant to get into physical project hobbies (e.g. low-voltage electronics, wood-working, 3D printing) because I'm afraid of all the hazards that I don't know about. Seeing these warnings (while greatly appreciated in a theoretical sense for me) just reinforces this fear I have.

Start in a classroom setting. Check your local community education classes.

Do woodworking. The whirling blades are pretty apparent. Wear a dust mask while sanding, and take comfort that Jesus was a carpenter and didn't die of respiratory illness/failure.

Don't do your own rigging or wiring, and you'll probably be fine. I do much of my own on both and I'm still ok.

Watch the tommy bar on your vise, and mind your marking knife. The apparently harmless things will get you because you pay them less mind.

Source: am a furniture maker. I still have 10 fingers. Haven't died of respiratory illness yet. Nor have I burned my shit down or crushed myself moving machinery. I have definitely made an unplanned trip for super glue after slicing myself with a marking knife.

To be fair, Jesus didn't live long enough for late life lung-related illnesses to manifest.

While I am not Christian, I am a huge respecter of Christianity on average.

But that made me giggle like a schoolgirl.

+ ear protection + eye protection. Table saws and routers need some healthy respect, some training won't hurt. You can do a lot with hand tools and that can be fun too (and pretty safe).

I'm most afraid of the router.

I've heard more people are hurt each year by angle grinders than any other tool.

I've only been hurt by two power tools: one was a drill, it slipped off the screw and made the pad of my finger into hamburger.

The other was my table saw, twice. Both kickback events that threw wood at my abdomen. I'm a pretty careful user, definitely not a cowboy. Mistakes are easy to make. I'm very careful with my fingers, at least!

> I've heard more people are hurt each year by angle grinders than any other tool.

Angle grinders are used a lot on jobsites by jabronis who like to remove the guard and suchlike.

In the workshop I'd be most careful around the bandsaw to be honest. It's slow moving and doesn't make much noise, but will cut through three fingers before you notice the pain. At least table saws and friends have a tendency to bounce off of bone so you don't tend to end up with full on amputations.

Kickback is somewhat nonintuitive though, so watch for that!

> Angle grinders are used a lot on jobsites by jabronis who like to remove the guard and suchlike.

And homeowners putting sawblades on them. Eek!

https://www.thesun.co.uk/news/3022661/husband-killed-when-he...

Tool-vs-tool danger comparisons are all apples-to-oranges comparisons.

How does a handheld danger that can move around or be dropped compare to a heavy, stationary danger that's in a predictable location?

How does one big danger rank against several smaller dangers? What about a clearly obvious danger vs a less obvious one?

Which safety procedures can you assume to be followed? Welders wear a mask and gloves at all times, but not everyone using a table saw uses a pushing stick.

How much experience and skill should you expect the users have? Users who are expecting a tool to buck or bind will be ready for it - does it matter that inexperienced users might not be ready?

If two tools are equally dangerous in a spacious workshop, but one can also be used up ladders and upside-down in crawlspaces, is it more dangerous because of that?

Do you just rank classic tools like hammers and drills, or do you have a broader definition? Is a ladder a tool, for purposes of the ranking? Is a car?

I own a bandsaw and it doesn't scare me. It just does what it's supposed to do. If you put your finger in it then it'll cut it off... So I just don't do that ;) A router can literally jump out of your hands, a table saw can pull you in, or kick out- you really need to know what you're doing (use a push stick, don't stand right behind the piece etc.).

> If you put your finger in it then it'll cut it off... So I just don't do that

Ah yes, simply don't make any mistakes ever ;-P

Fair enough though. I suppose the thing that makes table saws / routers / etc seem safer -- to me at least -- is because they look and sound scary. An untrained novice is much more likely to be careless around a band saw than around a table saw.

I've never been around a quiet band saw. Mines easily as loud as my table saw. To be fair, my table saw runs smooth as butter, but the band saw has some slight imbalance I've been chasing for a couple of years.

None of them sound like the router though. It's a banshee from a nightmare. I don't even like using it when it's mounted.

You need to be "present" when using the tool, respect it, and maintain very healthy safety margins. Before I flip the bandsaw switch on I think about what I'm doing. I don't get close to the blade. For me this is what makes this safe.

The router, even when you do all the above, it can jump, it can throw material off, it keeps spinning for a surprisingly long time after you power it off. All these characteristics make it less predictable. You need to understand it at a somewhat deeper level, how much can you cut, what direction to go, what direction is the grain going. You need to hold/brace it understanding that it can be unexpected and has a lot more power than you think. That's what makes it a more dangerous tool. Ofcourse properly used - it's fine.

I think we're basically agreeing. All I'm saying is that it's much easier for newbies to be "present" when using a tool that seems dangerous.

> take comfort that Jesus was a carpenter and didn't die of respiratory illness/failure

No, but it was an unfortunate incident involving some nails.

Just shows that have to be careful when working with others.

And I promise, I'll try to scale to my sarcasm.

Very cool! Superglue for cuts. The ol' waiter trick.

Yep. It's indeed possible.

Some best practices I recall growing up with:

Eyes, ears, feet, and lung protection.

Loose hair, jewelry, clothing anti-snag policy.

Keep body out of the kill line of potential RUDs.

Keep dust contained.

Keep fresh air moving toward you.

Push sticks, finger boards, and keep your tender bits out of the business end.

For circular saws, there is SawStop. https://www.sawstop.com/why-sawstop/the-technology/

Don't rush or work tired.

---

As blue collar guys, there are some risks my dad and grandfather didn't account for such as dipping their hands in and breathing carcinogenic solvents. In general, it's wiser to overdo PPE than play hard tough guy and shortening one's life for nothing. Safety regs are written in blood, but only after the fact.

Those hazards usually take a long time to kill you. It's a problem for people who do it 40+ hours a week, but a hobbyist is going to struggle to reach the level of exposure needed for it to matter. You'll learn about them and mitigate them long before it becomes an issue.

I've been swimming in all sorts automotive and manufacturing fluids and fumes and forces for years and it hasn't caught up to me yet. I know a shitload of people that have done it for decades without a scratch, and a lot of them didn't even try to be safe about it.

This is precisely why the hazards are so insidious: you're chugging along fine for years, and boom: you have a weird cancer.

I'm mindful of my finishing materials and proper ventilation and downright religious about hearing protection because the damage is cumulative. I know a bunch of guys I have to half shout at to have a conversation with. I'd rather not be one in 15 years.

I don't get why anyone would be opposed to wearing ear protection anyways. Loud noises are unpleasant and ear protection is an easy fix.

Though on the other hand perhaps I take it too far by wearing ear protection when hammering in nails or using the vacuum cleaner.

I'll gladly reach for my ear protection even if using a hacksaw is making too much noise. I think my cordless drill, impact driver, and table drill are the only powered tools I use without ear protection (mostly).

Anecdotes also lead to me knowing multiple people who've smoked cigarettes for decades without even a scratch (or burn), but that doesn't take away from the fact that we know statistically it's likely to cause serious health problems.

I don't know much about the subject you're talking about, and am definitely not trying to argue that it has the same risk as smoking 20 a day - just making the point that research rather than anecdotes is the best way to judge these things.

Of you use dedicated equipment, instead of doing all the BS people try on youtube, you are fine. Get someone to show and explain the machinery to you, and you are good to go.

What exactly you think are hazards in 3D printing? And low-voltage electronics? I am honestly curious to know... because I don't treat any of that as hazardous at all.

Woodworking can be hazardous when using power tools... but you can always go with hand tools only and that should be mostly risk free excluding possibility of minor cuts and bruises - but you can get these even when preparing food.

I do a lot of stuff around the house myself (renovation, making/adapting stuff, preparing my own wood for house heating, small electrical repairs, etc) and the only thing I am afraid of is the chainsaw. That thing can do significant damage even slightest mistake when being used, anything else is manageable given the usual precautions (protective gear, doublecheck that electric switches, wires, etc are not hot when working on them, etc...).

Yeah, I think the best way to phrase it is not "risk free" but "easily mitigatable risks with basic safety precautions and PPE". You just have to be disciplined about the precautions, and then even teenagers can do it safely.

> What exactly you think are hazards in 3D printing? And low-voltage electronics?

Fire (have your dry powder/kitchen fire blanket handy). Minor burns (hot-end, molten plastic, soldering iron, solder itself, hot components or PCBs). Not really more dangerous than cooking - I'd consider leaving a 3D printer unattended but if you leave a deep fat fryer unattended that can go very badly wrong.

Snipping off through-hole leads produces annoying metal fragments; if you're not already wearing glasses, wear eye protection.

> What exactly you think are hazards in 3D printing? And low-voltage electronics? I am honestly curious to know... because I don't treat any of that as hazardous at all.

This is exactly what they are saying though. I wouldn't have expected the cookie dough forge to be particularly dangerous but apparently it is because of nanofines/ultrafines - i don't even know what they are

"What exactly you think are hazards in 3D printing? And low-voltage electronics?"

Fire and fumes. Even low voltage can start fire or create some toxic fumes if it melts the wrong stuff and when you have a cold and smell little, you might inhale enough to poison yourself, before you notice.

And I am rather afraid of electricity, than the chainsaw. Because when the chainsaw is running, it is obvious it is dangerous. But a broken electronic component with an open circuit can be hard to spot.

> ...the only thing I am afraid of is the chainsaw. That thing can do significant damage even slightest mistake when being used...

After you carefully read the instructions, wear 9-layer wraparound chaps, cut-retardant shirt, forestry helmet, and chainsaw gloves, and you pay attention like as if you are on a gun range, you will have reasonably mitigated the risks. Most accidents happen when people grow complacent and don't take what they are doing seriously; even with all the PPE you can still screw up in a serious way if you aren't careful, deliberate and paying attention. I encourage anyone who is scared of chainsaws to read the literature. Even occasional users can make it a safe activity with some diligence.

I can relate. My example was welding. It's something that always was fascinating and I wanted to pick up for hobby work but was held back by fear. I hired a guy who's been around welding for decades and who was formally trained on welding to teach me. I told him how important it was for me to learn how to weld safely. He taught me at a pace that was very comfortable. Now I can safely weld as a hobbyist. I don't do it all the time, but I'm very glad that I conquered my fear and picked up a new hobby.

I would say that it's good to have some fear and respect for the tools and machinery that can do you great harm. Fortunately, there's a lot of good (and bad) videos on youtube. When I need to learn to use a new tool that is dangerous I always watch multiple videos and also search for web sites that discuss how to use that tool safely.

"the state of california is known to the state of california to cause cancer" - placard on jetway on way into california from origins unknown.

You can't know every risk. You can be paralyzed by fear and never grow. Life is a calculated risk. Do dirty things in a seperate space from your living. Wear PPE. As others have said the risks for hobbies and work are different. Hell we may all be having mesothelioma from the atmosphere in 30 years.

And sitting at indoor hobbies will also kill you from heart disease etc.

You are not getting out of here alive.

That's an incredible application of induction heating that I hadn't considered. How big was the coil?

Maybe 6 inch diameter.

Ah, my bad - looking at induction forge images and links in this thread, the coil was probably closer to 3 or 4 inch diameter.

Induction forge.

https://youtu.be/P_STrnP__D4

Kind of wild to watch him hold the rod with his bare hands while it gets red hot.

Steel is a poor conductor of heat. You cannot do this with aluminum or copper.

You can’t do it with aluminium or copper at all. There will be no heat to conduct, so hold it as long as you like.

A myth. Copper and aluminium won't heat on a consumer-grade kitchen induction stove, which only have a set of coils designed for ferrous metals, but restaurant kitchen professional IH stoves can use the different frequencies that heat non-ferrous metals, and a forge or melting furnace can indeed melt any metal, ferrous or not.

Why don't residential induction stoves have that capacity? Given the popularity of aluminum and copper cookware I'd think it would be pushed out. It's one thing people always bring up with induction ranges.

The electronics to drive the right frequency for efficiently heating ferrous metals (about 25KHz) are affordable. The electronics to drive the much higher (at least double?) frequencies for non-ferrous metals safely are not so affordable. It would add more to the cost than a new set of cookware. Cast iron is the king of cookware and works great on IH, anyway!

You can put a few mm thick piece of steel on top of the hob and then set your copper pan on that, as a workaround.

This is incorrect. The magnetic flux will induce an electromotive force that will cause a current to flow in any conducting material and cause heating if this material is not superconducting.

As an example, induction heating is a commonly used method in zone melting for Si-purification [0].

The effect is more pronounced in ferromagnetic materials because a larger flux is induced.

[0]: https://en.wikipedia.org/wiki/Zone_melting

False, and I have the scars to prove it.

You can even do induction hardening. Used for complex parts, of if you want hardening with a very well defined penetration depth.

The place I used to go had a gas furnace to heat the metal. A pitty I didn't find time to go there for ages now... Only downside of gas furnace, closed on on end, is the limited length of the stuff you can put in. I have an idea I want to try to forge longer things, but again, it is months now I didn't have time to get back to it...

You just have to put a door on the back of the forge. Or block the back opening with a firebrick.

Yeah, but it is not mine! Also, there is a open gas forge sitting right next to it. So, the place decided if some work and investment is done, it will be on the open forge. Which I can only support!

But yeah, I just realized the last time I was there was last year before christmas... Good thing anout this is: the day I retire I will definitely not be bored at all!

But is it really blacksmithing if you're using real fire? I mean that's the idea, to heat metal in an open fire and then hammer it, rinse and repeat.

The idea is to heat metal until it can be shaped more easily, traditionally by hand tools. That does not require a fire. In Roman mythology, the blacksmith Hephaestus used a volcano as his forge.

Traditionally it required a fire, yes, but that doesn't make it essential. I use silverware which is not made of silverware.

As a point of definition, in general use, a forge is not an "open fire". Eg, https://idioms.thefreedictionary.com/open+fire defines "open fire" as "A fire not contained by a fireplace or stove" and https://dictionary.cambridge.org/us/dictionary/english/open-... defines it as "a fire that you light outside, for example to cook on, or a fire in a space in a wall of a building, with a chimney to take the smoke away".

As I understand it, blacksmithing is typically not done outside, where it can be too bright to use the color of the metal to judge the temperature, and the fire in the forge requires some sort of forced air (eg, a foot-powered bellows forcing air through a tuyere into a constrained fire). This means the forge is not an open fire.

TIL blacksmithing has its own definition for "open fire", which is distinct from "stock fire". See http://www.faadooengineers.com/online-study/post/first-year/... . This means a blacksmith wouldn't say they only use an open fire.

Hephaestus is the Greek god.

D'oh! Yes, of course.

At least I didn't say elven blacksmith, working in the fires of Mt. Doom.

My point was that heating metal over open fire and using tools to keep the fire going is what gives it that medieval allure and makes it to be a bad ass hobby.

My point is that "open fire" is the wrong phrase. Just say "over a fire."

Medieval blacksmiths did not use an open fire.

I follow a blacksmith who uses a propane-heated forge to make knives and other small items. Here is a picture of the new forge in his workshop: https://ranum.com/badger_forge/2023/05/19/the-new-forge/ Here is a picture of the old forge in use: https://ranum.com/badger_forge/2019/06/04/silver-in-the-forg... . Using coal/charcoal would not make it more bad ass.

The heat and the smells are such a big part of the experience. They're really doing the students a disservice by taking that away.

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