Metalworking in space

I want a character to set up a traditional village blacksmith shop in the asteroid belt, and I would appreciate a discussion of the issues. My starting thoughts--

The heat source is no problem--just a reflector oven--basically a shiny surface on the inside of a plastic bubble.

The raw material is metals and silicates from the asteroids. I may need to work out some means of smelting to isolate, say aluminum for special purposes.

Most of the work will take place in vacuum to reduce the effects of toxic fumes in the shop, conductive and convective heat loss, and oxidation of the iron. It's really an attractive thought that no welding fluxes will be necessary, and that there's no rust or scale to worry about.

Hammering may be an issue--I think presses will be much more useful than an anvil. Anytime you swing a hammer, you would start to spin. I have worked up a kind of a peddle hammer so the smith can strap himself in and make two hammers swing together and apart symetrically, but I'm not sure if it would try to move around or not. A press is probably better.

The economics are still a little dim. I want an established, self-sustaining society where my smithy will fit in. That means orbital farms, a local supply of rocket fuel of some substitute, and what else? And no, he doesn't shoe horses--

GeorgeK said:

A = traditional village blacksmith
B = in the asteroid belt

These two premisses are really contradictory, so I'm having trouble understanding them together. If you have a spacefaring society why would you even have a blacksmith?

?society under embargo by parent society and resouces diverted for military and local politicos are ignoring food production? ok...

I'm not a physicist, but I'm wondering about the smithereens and whether those would be a problem for ships passing nearby. Maybe he'd need large magnets nearby to catch them, if even only for recycling?

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OK. Well, I didn't realize I needed to elaborate, but that's no problem.

I think it's a pretty natural development, for the same reason that blacksmiths appeared in villages hundreds of years ago. The raw materials and the energy are both right there--both nickel iron and non-ferrous rocks that contain light metals, there's plenty of heat from the sun, and the beginnings of social and industrial development. Here's my basic story line--

The youthful Horatio Alger character comes to town as a low level laborer on a construction job, and stays around when the job is over. He has studied smithing and knifemaking with the top notch oldtimers back on Earth, so he starts setting up his shop to make knives from the nickel iron asteroid next door. They are kick-assed knives, and he trades them for air, food, and energy to pick the rock apart into useable pieces. Pretty soon, the miners start coming around asking him to sharpen their drill bits, fix their magnetic and mechanical grabs, make a new part for the door latch on the airlock, weld up a meterorite hole in the hull. As time goes on, he builds a lathe so he can make shafts, bolts, and tubing. Then a welder, then a smelter. The back yard starts filling up with spare parts that nobody wants to throw away, so then when a rocket exhaust needs to be replaced, he can pick one out from the junk and fix it up. In due course, someone on Earth decides his knives are so valuable that he starts getting orders from dirt side, and eventually he is trading handwork for machining equipment and tools.

If you add in a farming colony and the related proto-industries (why not make fuel by capturing comets, and build spaceships in the belt?), there is a lot of room for low-level industrial technology. I want my characters to become self sufficient, and this is just one of the steps.

ETA--
If you ignore the orbital mechanics and my own utter lack of business ambition, this story summary is about how my own blacksmith shop has developed in rural Alaska. Originally a coal forge and anvil, now it also includes a plasma cutter, mig welder, 2 lathes, and sttuff that should eventually turn into a vertical mill and a casting furnace. Although technology is readily available elsewhere to do anything I can do (actually we--I have an accomplice), the supply line is wicked long and expensive, so that changes the economics a lot.

www.galenavillageblacksmith.com

GeorgeK said:

"Can you forge a blade in a vacuum?" I don't know enough about the physics involved, but I thought part of the process involved getting carbon into the blade. If you are using a solar oven as your forge, you don't have any coals. Is that a problem? Actually that would be a really cool experiment to write to NASA and see if they'll give you a ride to test it.

"Why do the miners want the knives so bad?" Are they just that cool, or do they serve some special purpose? Are there spacerats in the mines and sometimes you need to defend yourself, or is it just to cut open the bag of self heating soylent chips? I live on a farm, so I understand that you need a good knife on you when you walk out the door, for whatever, but either the supply coming from Earth has to be abysmal quality, or his knives have to be top knotch (ok maybe that pun on the spelling was a bit too obtuse). I undestand about fixing tools. Take it to Horatio and you'll be back to work in three days, or radio Earth and the new part will be here in three months. That one is a gimmee, so I'd lead with that as his initial startup in asteroid blacksmithing unless there's something going on with the knives in the background that is crucial to the story. Then the customers start drooling over the knives while waiting for the drill bit.

BTW, neat website, I especially liked that chandelier, but you haven't updated your copyright since 2004. My first thought on noticing that was that maybe it was a defunct webpage. If you are selling stuff from it, or using it as a way for them to contact you, make sure that the customers don't assume that you've fallen off the planet.

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Thank you, GeorgeK. This is exactly the kind of engagement I wanted.

Concerning your two questions--

The first one is a technical one, and the answer is clearly yes. As you mention, it's possible to get some carbon absorption in hot steel, but it basically requires a charcoal fire, and perfectly respectable steel can be made now with as much or as little carbon as desired. Obviously, that raises the issue of how much carbon does the product need, and what was in the steel to start with, but that's the point of pattern welded or Damascus steel. Knifemakers manipulate carbon content every day, and a vacuum would actually make the process better and easier rather than harder.

Why? Good question, but not unanswerable. Suppose you are looking at a knife catalog, and find a nice one for opening cans of survival rations, but the freight for a knife from Earth is $100k. So you might go to a friend of a friend who makes knives out of old turbine blades and rocks, and who will do the job for a sack of scrap titanium alloy, some selected hematite, and a bag of turnips, and when you show him the catalog picture, you might mention that it would be nice to have a wraparound handle, a hammer head on the back of the handle for persuading that sticky latch on your cargo compartment, and a magnet to test for iron content in the rocks. Well, plus they are cool. (Oops. I thought to insert a picture here of a nice pattern welded steel blade, but I don't have any of my own work to show, so look it up yourself if you like. Embarrassing...) You are right about other tools, but knives are probably non-trivial.

On the un-numbered third point, you are right about my crappy web site, of course. My computer-geek consultant sister made it back in '03, and it has lain dormant ever since. Oddly enough, the main product we sell is hidden at the very end--woodworking holdfasts.

I have some thoughts about the value of transportation for this enterprise. Lot of long distances involved, and blacksmith shops are known for being non-portable. It might be good to have a common orbit with a commercial center like one of the bigger asteroids--just kind of stick around the farm and the transportation hub. Larry Niven's stories come much to mind when I think about colonizing the belt. You can see why--

GeorgeK said:

"Dag Gum it! Horatio, I want me a knife blade that'll cut these there steaks at Luna's Restaurant."

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Thank you GK. I guess it wasn't real wise to let this thread wander off to knives anyway. Think of them as a metaphor for commonly used gadgets.

Although I don't want to skip over the important issue of a credible market for handforged stuff in orbit, I would like to see if there are any other snags to work out. For one thing, I need some conflict--I'm very bad about failing to challenge my characters, and a good emergency or two would be worthwhile. A bit of a love interest, of course, and some folksy local characters and color.

Here's a question, just for bait. What's the core of the asteroid belt economy like? I picture a bunch of homesteaders doing their thing mining, farming, and trading among themselves, but how do they develop self-sufficiency for, say, repairing and building space ships? I think I need a gold rush or a land rush or some such.

I really appreciate the comments. Let me see if I can make one response to several notes here.

From Ambri--

If you're looking for a basis for your economy, and some conflict, maybe there's some colonist/ homeworld discord, along the lines of the English/ American colonist strife that led to the American Revolution. I.E. high taxes and tariffs on goods, abuses and nepotism in the off-colony people sent to govern it.

Oh, and I don't know how "hard" you're wanting to go in terms of hard SF vs. bolognium, but you could always have the asteroids contain uranium, some as-yet undiscovered material (unobtanium) or maybe be the last outpost and supply post on a long space lane to the outer reaches of the galaxy.

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That's good. I like the parallel history thing, and particularly the supply post possibilities. My thought now is that the main resource is fuel, either gas from comets or dust from the asteroids for reaction mass. There's a good point later on about moving the venue to the Jovian moons, but that's a sub-issue.

Xelebes--

NASA is currently testing a metal replicator which uses beams of ions to slowly build in a vacuum. I would suspect that a satellite replicator orbiting the asteroid would be used for needs of items made in metal.

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Noted. Thank you. High tech stuff is fine for my scenario, and the replicator may fit in nicely next to the forge and the scrap pile. FWIW, I think there may turn out to be some diamond dust available from an old lense grinding project, and I may use it for a coating on some of the cutting edges.

Lhun--

A local smithy might actually be a good idea, the transportation costs certainly are an incentive to produce as much as possible on site, but the question would be how a village blacksmith compares to more modern, automated production facilities.

Complete self-sufficiency for a high-tech civilization isn't going to happen with small asteroid communities. You need a population base of several millions to support that.

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Dude--Always a pleasure to hear from you. I can't seem to find wherethehell I saw that thing about stages of spaceflight, but basically I hope and expect that people will eventually inhabit pretty much all of the solar system, and grow to the many millions of population that you mention. Slowly. I guess this would be one of the transitional stages.

"Subsistence" is a sort of a term of art in my part of Alaska. On one level it means living off the land. On another, it means using anything you can find, even if it technically belongs to someone else, and especially if it belongs to the gubment. I'm not sure why I mention that, except it really blurs the concept of money, and maybe that's what I had in mind instead of self-sufficiency. It's surprising how many resources there are when you look for them really hard. And don't look too closely at the serial number on that metal replicator, dammit.

Pthom--

The asteroid belt is pretty much a great preponderancy of vacancy.

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And Lhun again--

Well, you can go with jovian moon systems. Travel to different orbits is more difficult than from an asteroid belt, but within the orbit, travel between the moons is pretty easy and quick.

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Good point. Lemme think about it for a while. The advantage of the asteroid belt is that the arrival and departure energy requirements are low, and that it's closer than Jupiter, so it might be more of a community with the Mars and Earth orbits. There are disadvantages too, because it's a lot like getting off the freeway and finding out that there's no town at the exit. Jupiter's moons should have a lot of good resources, so it may be worth going farther out and deeper into the gravity well. Jupiter would allow for some slingshot maneuvers that might help, but the asteroids amount to a big parking lot in some ways.

GeorgeK--
Thanks again for the summary. Your comment about big mining corporations reminds me of the Hudson Bay Company and the early fur trade in North America--one big company that trades with and through a lot of agents. They had some competition from the French and Russians...

benbradley said:

I'm thinking it has to be helpful to do this in some amount of gravity. It can still be "out in the vacuum" with a big reflector to heat up the forge or whatever, but if you're going to melt ore, gravity will be the main thing to separate out all the different things in the ore. You can get this as simple as being at the end of a long bar or cable with a weight (or something useful) at the other end, with them rotating around a common point. The plane of rotation would be perpendicular to the Sun so it would stand still relative to the reflector and heated vessel.

Even for quenching and tempering and stuff ... I saw a guy demonstrating making knives, he would heat up the blade to what he thought was a nice temperature then drop it into a bucket of water or oil depending on how fast he wanted to cool it, and tell how that makes the steel stronger along the outside. I'm sure you could somehow have a spray or something equvalent to dipping in a bucket of water in zero gee, but having a bucket just seems easier. It seems like you gotta have a centifuge if you're going to do any processing of ore.

I'd think this would be the way thing would be done too, OTOH it's always good to have low-tech tried-and-true methods available, including the knowledge to do them.

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Hi BB--

I agree with most of what you say, and a bit of acceleration would be nice for, say, bathroom functions if not for smelting and quenching. My immediate take on separating metals from ore is something like roasting meat--slow heat at a critical temperature until part of it liquifies and separates by surface tension, possibly recovering oxygen or other gasses in the process.

As someone mentioned upthread, fugitive waste in the form of dust and flakes (GeorgeK provided the neat word smithereens) is probably an unacceptable form of industrial pollution, sort of like the orbital trash that's starting to cause problems around Earth. And the thought of an unrestrained sphere of hot liquid metal in a habitat is a bit scary.

Quenching blades is a minor issue compared to making the blade. I figure if I can pee in space, I can quench steel ;^), although the activities aren't necessarily related.