Can You Cast an Iron Sword?

[@htme]

Thanks again to Bespoke Post for sponsoring today's episode! Get 20% off your first monthly Bespoke Post box when you sign up at www.bespokepost.com/htme20 and use promo code HTME20 at checkout!

[@450bigpat666]

You need 2 openings and vent holes in a sand mold otherwise air is trapped.

[@thekak2627]

After the steam engine you should move to a paddle steamer, combustion engine and stuff like that

[@greggv8]

Melt a cast iron engine crankshaft. That iron takes massive twisting, compression, and tension forces without breaking.

[@LecherousCthulhu]

If you have to make cast iron anything then a cast iron hammer head sounds pretty good. How you create a handle for that, Idk, but it's probably the best option

[@michelguevara151]

for a cast sword, it would be better to use a gladius style

[@wickideazy]

I've been studying melting & casting in preparation for starting up as a hobby, and I'll echo what others have said: you need an exit vent for your molds. The molten metal is hitting the trapped air and compressing it, which is stopping it from filling the mold. You're also getting a lot of steam explosions and spatter because there's too much moisture present; as BigStackD (another KZbinr you should check out if you want to look into casting) always warns his viewers, ALWAYS preheat your stirrers, skimmers, and molds to avoid this problem.

[@MajKetchup347]

I've been following bigstackd for a while as well, also interested in starting up a metal melting hoby. One question I still have that bugs me is how to do steel melting at home. Bigstackd always gis his steel to his bud but I'd rather be able to melt it myself. Do you know of any resources that could help get me in the right direction or is this just my wishful dreaming that isn't going to happen?

[@wanderingcalamity360]

@@MajKetchup347 Try a ribbon burner or two in a mini metal foundry. I wanna say Old Hickory Forge has a video on a ribbon burner build.

[@skylerlehmkuhl135]

@@MajKetchup347 One way to go about it is using electricity instead of gas. You can get carbon gouging electrodes for a stick welder; while a propane flame is only barely above the melting point of steel, an electric arc is several thousand degrees hotter and can melt it easily. Keep in mind that the air will be trying to cool your crucible, so insulate it well with firebricks or ceramic wool; if you're having trouble getting the whole thing to melt, try a smaller crucible or a higher power welder.

[@keithklassen5320]

I was wondering, the molds they made looked quite complex and thought-thru but I couldn't see any exit vents, which is confusing cuz how do you get to the point of knowing how to properly mix sand for a mold and do lost wax without also knowing about venting?

[@rachdarastrix5251]

I thought you then broke the caste then heated the iron and beat it on the anvil.

[@nickfenix3892]

When your using the sand mould system you need to have a exit for the air to leave from

[@christopherconaway3549]

ya idk why nate didnt put the vent tube in

[@hanelyp1]

In sand casting, there are pores between the sand grains that can vent gasses. Depending on various factors that may not be enough, and a vent or riser opposite the feed is needed. Vents reaching almost, but not quite, to the pattern can also help.

[@kernnus39]

@@hanelyp1 Ok but an exhaust pipe is always easier to get the air out quickly

[@jaythewolf7216]

also heating the mold before using it can help a lot also. some of the splattering of liquid metal is the rapid temp changing happening. almost like how dry ice will skate around on most surfaces tell it drops the temp enough to stick to it. you want the metal to more or less stick to the mold not skate around on the surface of it.

[@SunG34r]

Have you heard of a puddling furnace? They used to be the predominant method of the manufacturing of steel before the bessemer process

[@christopherconaway3549]

i did my captone in college on ancient chinese metallurgy, and i came across their early forms of the pudding furnace. fascinating stuff

[@uberchipmonk2568]

In ancient times, the Chinese were the first to learn to smelt pudding. The first flavor was rice.

[@tristantheafflicted]

Or even the more primitive version, the finery furnace.

[@panzerlieb]

So there was one of puddling furnaces not far from where is was raise. Actually it was a sister furnace to the cast iron furnace just a couple of mile away. The purpose of the puddling furnace was to lower the carbon content of the iron pigs so that they could be forgeable. Both furnaces were colonial American era (late 18th century). The cast iron furnace still exists, but the puddling furnace is long since forgotten. The Bessemer furnace pretty much made the puddling furnaces obsolete.

[@beowulfshaeffer8444]

You may want to use two-piece molds and preheat them before pouring. Also, the Primitive Technology channel has a couple videos about making primitive cement from wood ash. Mixing that cement with silicate sand might get you a concrete mix heat resistant enough to keep your furnace from melting, much like the plaster and sand mixes used by TKOR, Nighthawknlight, and others.

[@corwinweber693]

It's a nice idea, and it MIGHT work, but..... I don't know. I'm not sure whether it could handle that kind of heat or not. Maybe?

[@beowulfshaeffer8444]

@@corwinweber693 Yes, a bit of a risk and probably worth testing a small piece under intense heat before building a whole furnace out of the stuff, but considering that Nate's furnace didn't melt when lined with a similar mixture and was still able to melt iron, I think there's a good possibility that a primitive version would perform well.

[@tristantheafflicted]

I would most likely advise against that since most cements tend to hold some water in them after curing solid, which is why you avoid modern regular cement in most high temperature applications since it'll convert to steam and blow the cement apart (even firepits). The primitive ash version *might* me ok but without a good deal of research making sure, I wouldn't risk it.

[@beowulfshaeffer8444]

@@tristantheafflicted You'll really need to look at The King of Random or NightHawkNLight to see what I'm talking about. Most of their soup can, oil drum, and bucket forges (and even their foundries) are lined with a cement made of plaster of paris and sand. These builds and demonstrations are documented for your viewing pleasure.

[@anon_y_mousse]

@@beowulfshaeffer8444 Andy could take another lesson from Primitive Technology, make a blower for the furnace and one of those ceramic redirection things, whatever they're called.

[@riuphane]

Both Good And Basic and NFTI!? This is amazing! Been waiting for some collabs with Nate, but bringing everyone into one video is awesome!!

[@NKG416]

i think you should working with expert (like the beer episode), this has so much potential but ends up half assed, sorry to say this

[@joakes33]

That's great that you did a collab with Nate I can't wait to see his video he does some really great amazing stuff

[@52Ford]

I really appreciate the effort, but I was shouting at the screen when I saw y'all trying to pour cast iron into unvented molds. With the cobb mold, I would have burned off the 3D print (lost PLA method) and poured the iron while the mold was still hot. Since you already have to model it up in CAD, oversize your print by about 1% to account for shrinkage as the molten cast iron cools down. How's the new shop build going?

[@resurgam_b7]

Awesome video, I'm going to have this video on tap for any future "BuT I kNoW tHeY dEfInItElY dId CaSt IrOn SwOrDs." conversation that I have :D A minor correction: Cast iron =/= iron that was cast. Cast iron is a specific material, iron that was cast can be any kind of iron that you melted and poured into a mold. The act of casting doesn't necessarily result in a higher carbon content. It can, and for your primitive furnace attempt probably would have, but that would have been a function of the heating with charcoal, not the melting itself. The reason you don't want to cast a sword is because of the poor grain structure that results from the process. You also wouldn't want to forge a sword from the material cast iron either though, because of the high carbon content which you mentioned in the video. The end result of both would likely be the same, a brittle sword, but the mechanisms by which they became brittle would be different.

[@damien667]

Great to see Nate! Hope y'all work together again

[@pauljs75]

An interesting related line of research may be a wind-fanned forge. Seems there are locations in Europe that used either coastal ledges or bluffs or slopes on the side of a valley that take advantage of natural wind conditions to fan the firing of the furnaces. There would be scoop-like structures built that would channel the prevailing wind that hits a rock face into one of the lower chambers where the firing was done. It may be one of the possible ways they got stuff like crucible steel, as it would take much less human effort to sustain higher temperatures. Not sure how you'd recreate that, since having an effective setup seemed to be highly location dependent with a consistent and somewhat sustained dry wind. As far as casting a more steel-like iron... Might be some hybrid processes? An initial casting and then hammering out while red hot. (Some aspects of forging, but perhaps not as intensive? It would help with voids/cracking, but less actual forming of the material.) The main thing to make something like that strong would be the tempering/annealing process.

[@Punkysimpa]

I would love to see more woodworking projects, maybe a wood lathe??

[@YggdrasilSDT]

Grandpa amu has a home-made pedal and belt powered lathe video.

[@kernnus39]

I can point out some points about why the pan didn't work, First point I didn't see any holes for air to escape in the mold, second point, The metal has cooled down too quickly, perhaps heating to a higher temperature will make it liquid longer.

[@danielporter8481]

Yes, a whistle vent in casting is essential. Green sand is 6 parts sand and one part clay with just enough water to make a fist ball. Water in molten metal will explode, dry your tools. This should be stressed for safety. A caste sword is the beginning process. next it needs to be heated and hammered to compress the steel into a uniform structure, forged, tempered etc.

[@bramweinreder2346]

Fun fact: historical swords used to break all the time due to poor edge alignment. Even modern reproduction swords made for HEMA break occasionally, which means that either we got stronger or don't understand sword fighting very well... There's no reason you couldn't still quench and temper your blade, which would make much difference. You could also finish it easier with more traditional techniques after tempering. But even then you'd have a sword that's made from an inherently brittle material. Maybe if you reheated it in a coke forge before quenching, but idk. Bronze is inherently softer, but did usually get work hardened by hammering the bevels. That's a different technique than grinding but does the same job, but also has other benefits that also kinda apply to other metals, in a way that the material gets more consolidated near the business end.

[@TheoryMaK15-255]

The Metal bars we used are industrialized casting, and that is how it's made. melting and mixing the cast iron and making it a bar, so it can be shaped and forged into a sword. Before the industrial revolution era, they were casting all forms of metal to make it into something.

[@uberchipmonk2568]

Based on other KZbin videos iv watched, your sand molds did not have holes for air to escape, and possibly the sand needed packed better.

[@Hubertoser]

And you can't melt junks of metal big as that, in your mud furnace, you have to make small flakes, and even then...

[@jakedingwall7688]

I love watching this because you are great at telling your audience about human history.

[@lmkcrazy]

Air escape holes need to be added to ur molds and potentially extra spouts to make it easier to poar and fill in.

[@MobMentality12345]

Glad to see Nate here too! Cool collaboration

[@Artifying]

You might have this in the pipeline but I would love to see a video on ancient jewelry like refining precious metals and cutting stones.

[@nickdavis5420]

It’s weird you can absolutely forge a bronze sword . Now if you can make good heat you can cast iron without changing the mix too make it brittle it would just need too up the heat . They pour steel now all the time too drop forge .

[@danielstellmon5330]

You may not have gotten the items you wanted, but I was entertained. Thumbs up from me.

[@matthiasschatzer8641]

But for like spearheads, wich dont bend much, would it be almost the same as forged ones?

[@TheSpookiestSkeleton]

well if it's stronger under compression, perhaps it'd be good as a dagger or a mace head or a spearhead, something that doesn't need to bend very much

[@jasonkeats931]

Good and Basic use horse dung to make the cob for the bloomery. If they had fed their horse corn, I wonder if they might have been able to say that they had "corn *in* the cob"

[@timothywilliams7264]

To make the pan. Get to boxes with sand packed tight. Make sure you an put the boxes to geather. Make top imprint in one box an then bottom in the other. Put the boxes togeatherso it dont leak an. Have a hole to pour metal down. It will be easyier

[@simonjester4133]

maybe you could try semi-forging after the casting to drive off the carbon until you reach approximately one and a half percent?

[@Cristopher.C]

So! Can You Cast an Iron Sword? Well, First things first: Let's 3D print a frying pan! :D

[@adammurphy2848]

Video Suggestion: Try making something like an Edison cylinder, its like an early version of a record.

[@leemday5731]

I would have liked you to have tried to reduce the carbon by leaving it in the fire for some time or just or just normalising hardening then tempering would be interesting to see the result!

[@gundanium3126]

Why sandcasting and not the stone casting you see in the movies? you could heat the stone mold up. is my thought. and you could mold it, then cook it down a bit to lower the carbon content, and then partially forging it to consalidate the form.

[@WalrusJones185]

So one thing with cast iron is I do remember there being a malleable form of cast iron that has been baked to make it more able to withstand tension.

[@robertshort9487]

if you need to mass produce swords, and can melt iron, then casting swordish shaped billets for later finishing makes a lot of sense.

[@matthewmcnamee2864]

Th problem is with the structure they would need to do the same ammount of work for those

[@robertshort9487]

@@matthewmcnamee2864 they would need far less work. And would still be far better than arming people with sticks.

[@matthewmcnamee2864]

@@robertshort9487 it depends on the armor and stick a bo staff can do alot of dammage compared to something that continously breaks on contact with another weapon just look at the vid infront of you the grain structure is random adding weakness vs forging where it's stretched along the sword so for the sword shaped billets they would need to fold and restretch it which would work like a normal sword and that case might aswell start with a bar it's why the cast iron sword broke and the forged one didn't

[@dj1NM3]

I'm still slightly surprised that a closed vertical mould, like used with the bronze sword, wasn't used. It might have been a lot less work in finishing, after it had cooled. The resultant cast iron "sword" would still be heavy and brittle, but it might have looked nicer straight out of the mould. Using the opening scenes of "Conan The Barbarian" as guide on sword-making was perhaps not a good idea.

[@MeleeTiger]

Traditionally it seems busted yeah, but when you consider that the movies that show the method are fantasy... My mind goes to how many such settings, especially if dwarves are involved, tend to have oddly modern methods like crucible steel. Aside from that, I'm surprised that you didn't try to do an open faced pan casting? I could also see using cast iron for short and stout trust focused daggers or spear blades, or a thin cooking knife that won't be hitting anything too hard?

[@TonusStoneshield]

In the future I suggest annealing it after you cast it, it'll help the coarse grain structure rearrange into something less likely to shatter.

[@stanislavstrecker7476]

You have to leave draining holes, for the air to come out. otherwise you will get bubbles and it wont flow. Also, the mold has to be 100% dry. wet sand is no good

[@FlyingDaddy721]

17:15 RUNNNN!!!! every bug for itself

[@LittleDergon]

Would love to see the slow Mo guys do this as get a super slow shot of the break

[@user-wg6fe5uj8r]

Higher carbon is ok for shorter blades because they don't have to withstand as much stress as a sword would. may be turn one of the short cast iron pieces into a knife?

[@Coyote66MB]

From a former iron foundry worker your iron temps need to be between 2500° and 2600° also you definitely need vent holes in your molds

[@billwithers7457]

To be fair to Lord of the Rings, only the spine of the blade was exposed to the air, and it was properly forged, quenched, and tempered later. So even if a bunch of those blades had defects, those defects may have been corrected later, or the bad blades may have been re-cast in new molds.

[@PhantomSavage]

It also wasn't iron. I'm fairly certain it was "Mythrill" which is a metal that doesn't exist in real life, because its Elven in origin.

[@CaptnApathy]

I always assumed the swords in movies were cast for quick initial shape, then worked on and heat treated after that. would that not help at all?

[@antonjanssen3549]

Depends on material choice. Almost all modern steel is cast into gigantic billets which are then hot rolled or forged into a more manageable size. Casting steel just requires temperatures which are not realistic for basic and small wood or charcoal fired furnaces. With non modern equipment you are restricted to cast iron, the difference is in the very high carbon content, which significantly reduces the melting point but makes the material a lot more brittle. No amount of working or heat treating will change that.

[@Aggemannen117]

Tbh, I get why the Uruk-Hai got cast swords as they have them mass produced and they don't really use finesse when it comes to sword fighting.

[@taylormullins3820]

I wonder how the cast sord would do if you cast it just to get a basic shape than forge it to the final shape before grinding the edge on it?

[@StarScapesOG]

Only thought i have, sword wise, is cast a bilet and forge it to shape....

[@givannoraices6605]

Did you guys add bentonite clay to the sand? The clay will add structure to it which is needed for iron casting. This is how green sand was made, which is what molds were made from in the industrial revolution but I could be wrong it's been years since I read up on it.

[@crypticcorgi8280]

Arrow tips are more about compression. So I wonder if cast iron would be better as an arrowhead.

[@edwardarmstead2306]

What if you tempered it multiple times after the cast and vibrated the casting tray to release air bubbles?

[@virtualfather4117]

Why no vent hole when pouring into molds

[@SaucedTech]

You had nowhere for air/gas to go. It wouldn't accept more metal because it's only outlet was blocked with iron. Next time add a small vent on the opposite side of your box and it will be much more likely to fully fill.

[@DragonstarFighter]

The problem with casting the bronze one is that bronze swords were forged, they had to be annealed, but the work hardening was very important for the blade edge

[@77yvurc]

title is a bit misleading, but still interesting to see

[@vahlte]

This made me curious: Is it possible to forge a bronze sword? One issue with bronze is how soft it is, but could forging it like iron help?

[@Techno_Nomadic]

Yes. You would forge the bronze hot, but at a much lower temperature than anything ferrous. Also the copper alloys can be hardened by working the surface of the metal, and they are softened by heating and quenching in water. I worked with a master smith that had a bronze chisel that would cut fully annealed iron.

[@SunG34r]

decarburization could turn that into a better steel... allegedly

[@FrozenHawkHunter]

Could you forge a iron core then cast iron around it? Or cast the blade then forge wield iron to both side of ? Basically make a iron sandwich with the cast in the center. Probably more work then it's worth.

[@dukesilver9267]

Am I missing something? That primitive furnace looks like they just covered a tree in cob and burned the tree from the inside out lol.. I may have to get caught up haha

[@sbkpeace.24]

A few great door stops 🤣

[@Orangatangerine]

So if cast iron is good at compression I'm wondering whether it might work for a stabby sword rather than a cutting sword which requires both compression and tension strengthb

[@kyidyl]

Why not cast lower carbon steel instead of cast iron? Is it because you can't get the temperature high enough? I mean I guess it makes sense that they might not be able to melt steel back then even if they could forge it. Also did you harden and temper it...? Not that I think that a forged sword is the way to go, it's just that I've always thought the same thing about movie swords and this didn't answer my questions...

[@deanj2487]

The little bug as you smash its log home 👁👄👁

[@ericeaklor1300]

Note to one's own self, DON'T EAT ANYTHING YOU BAKE !

[@kwaaaa]

3:35 scat people beg to differ.

[@tobhomott]

A lot of armchair metal casters here are blaming too cold iron on the molds being airlocked due to a lack of vents.

[@drnotof6124]

Nice episode

[@joshneandertallclark1978]

With a high temp metal, would you be able to mix out the air bubbles in the iron prior to casting (kinda like epoxy), or is it a second physical reaction while the cast iron is cooling,making any mixing a moot point?

[@RatoCavernaBR]

If cast iron is better for compression shouldn't it be better for a hammer than forged? Can you make some tests?

[@PolishBigfootCircle11]

What if you were to cast the iron sword, then hammer forge the bevels in, and then give it a proper heat treat?

[@cvspvr]

the steam engine build is going to be awesome!

[@DanMaker]

steel can be cast too. That's a challenge you could try.

[@kresimirvalentak1946]

Conan's dad first cast the shape of a sword, then forged a cast, and finally hardened it in the snow. Therefore, your examination and reconstruction of the procedure is full of holes. Second time, complete the process and compare!

[@bullvinetheband7260]

How about a crucible made out of stone placed in a furnace?

[@revol2933]

Actually, Lord of the Rings is on the point, cuz that scene from Fellowship of the Ring was meant to show how quick & poorly orcish weapons and armors were crafted.

[@sypoth]

Next time, do a forged Bronze sword.

[@leifgiering]

Is nobody really going to talk about how that guy is handling horse poo with his bare hands like it's nothing?

[@jefferymuffinsbobmarley6128]

very interesting with the horse dung, looked kinda satisfying XD probably kinda stinky tho

[@paanjaan]

i would say sure you can cast sword from anything, the thing is it wouldn't be much of use after few strikes ... if it still exists in one piece

[@Bpg2001bpg]

I feel like people add borax to their melted metal for some reason. Idk if that's just aluminum or copper though.

[@feint2168]

Love the content!

[@wtechboy18]

y'all gotta preheat them molds.

[@hortus2970]

Thanks for this video! I was wondering exactly this while watching GoT: Why on earth are they casting valyrian steel? And why is it supposed to become a great sword? Now finally I have the video proof that this was fictional ;-))

[@YggdrasilSDT]

You said you wanted to try primitive but then you used an fan electric fan with the clay kiln. Should have made a bellows or something.

[@mitchellakruchten6242]

you need vents in your molds for iron

[@tracybowling1156]

Does it feel weird to make videos by yourself? Is it fun by yourself? For some reason, that ? Popped into my head. I probably won't get an answer, but IDC, I wanted to ask! ☺️

[@davideloewen]

It's almost like there was a reason Narsil shattered...

[@Gobeman]

I'd say it probably was eaiser than obsidian without having watched the video yet

[@pineapplebanana9368]

gop 👍

[@OmniversalInsect]

At least the cast iron sword doesn't break into a million pieces straight after pouring

[@dylanvaughn9600]

Cast iron and casted iron are different, cast iron is an impurity when making steel, lumps stick together and absorb air

[@yaroslavpanych2067]

I have 1 big question: why in hell you are mixing cast-iron as iron alloy, and process of casting molten iron? If you are making sword from cast-iron (no matter, by casting or by forging) you are getting what you expected to get, as opposite of casting sword from molten steel! Why it is a discussion at all?

[@beardedxj]

Could you take cast iron like that sword then forge it? Would it do anything?

[@AlucardNoir]

Can you quench and temper cast iron?

[@cahproductions4695]

It looked like your casting molds didn’t have any gas spouts. Iron reacts violently with gasses that are in the air. Maybe if you added gas vents, then pumped a heavy, inert gas like argon into the mold it would work better.

[@loganstrong5426]

At the very least, they needed a spot for all the displaced air to go. It doesn't bubble up through molten metal as well as it does other liquids.

[@Natulxs]

@Logan Strong It looks like they were using an oil sand like petrobond which theoretically let's gasses escape pretty easily for aluminum and bronze castings at least. Maybe iron just makes way too much though.

[@corwinweber693]

@@loganstrong5426 Yeah they needed something as simple as a vent if nothing else.

[@jimburton5592]

He hasn't unlocked the noble gasses yet

[@diablominero]

@@jimburton5592 He has unlocked soda ash or limestone and vinegar, though. Carbon dioxide is technically an active gas, but if you're not TIG welding I doubt you'd notice the difference.

[@masterimbecile]

14:00 blade smiths don’t make mistakes; they just make shorter swords.

[@abrahamnarvaez1730]

Why is your sword only 3 inches long Because I wanted it to be shut up

[@duckman4928]

You can´t call that sword. Swords has blades, this has not blades, this is insult to all swords.

[@jeremykiahsobyk102]

@@duckman4928 Calm down, it's not that serious. Plenty of real forging videos out there if you can't stand the sight of some guys having fun and experimenting around.

[@jimmywalden1615]

You should crest vent holes in the mold next time it didn’t want to flow because of trapped air and keep a propane or map gas torch with you so you can preheat the mold the piping and spattering was because of the presence of water it also help to preheat the mold to ensure a good flow and it doesn’t harden to quickly

[@outforsummer5818]

thank youuuuuuuuuuuuu the sand has to have a small amount of moisture to keep its shape if it’s a closed cast but they alwaysssssss have to have at least one vent at the opposite end of wherever you’re pouring i so hope he sees this

[@unlink1649]

I really wished he wouldn't half ass everything like that and for once prepare a proper mold with the carbon dioxide moulding, at least clean the slag off of you molten iron and then pour into a heated mold. The mold was made of basically beach sand that he shaped by printing a crude sword into it. He then started pouring from the middle into a mold that wasn't even level. I'm just dumbfounded at how many mistakes you can make. Nothing this guy does resembles quality and it's literally the only thing he does. I bet this was his first pour as well and he didn't even test the process to find out if it was any good. He just went with it like "meh good enough". So disappointing.

[@SuneSensei]

@@unlink1649 It's so amateurish, this series has been going on for so long now you'd expect them to either have learned by now or done a little bit of research.

[@kannonpq]

@@SuneSensei They don't care about doing it good. They care about putting out a good enough video. The problem is with everything just being "good enough" over and over, it starts to look AWFUL.

[@alexisvulfiaawenfern8112]

I have the feeling that cast iron would be good for mass producing arrow heads.

[@bl4cksp1d3r]

Ohh, ohhh, yeah I can see that :o

[@elijahjamesperez8936]

The Chinese actually did that

[@guicky_]

@@elijahjamesperez8936 they still do lol

[@harleymarshall6929]

Or spearheads. It should work really well as a material for making a purely thrusting point

[@Kez_DXX]

@@elijahjamesperez8936 mass production for the win

[@KewneRain]

1.) It's not hot enough, you need to get well above its melting point to ensure it flows into the mold properly 2.) the molds need to be vented in some way, the air inside them needs to go somewhere. The wet sand will hold its shape but it's not porous enough to allow natural venting 3.) the bubbling in the open molds is a result of the mold containing moisture. Even the smallest drop of moisture can result in a steam explosion that sprays molten metal all over and causes bubbles in the surface. Preheat your molds until dry whenever possible.

[@noirekuroraigami2270]

would tempering a cast iron sword reduce its brittleness

[@KewneRain]

@@noirekuroraigami2270 no, it has too much carbon

[@TimPiatek]

With the understanding that the proper steel would require higher melting temperatures... why not try that? Would be more interesting, since I honestly don't know what to expect from a cast steel sword.

[@kubawakuluk2443]

Well, the topic of steel casting is really complex. And as far as they dont control it preciselly there could be everything. The type of alloy will be propably the most significant factor as well as cooling time and melting temperature, since the grain structure depend on this aspects. I think that casted steel sword might work if they use both the proper alloy and precise melting/casting/cooling process.

[@herscher1297]

Its not really possible to reach the meltingpoint of mild steel without modern technology (outside of a kilm) and it would react strongly with the air. The end result would be a mostly normal steel sword.

[@bradley3549]

I don't think they really covered exactly what they were using as a raw material here but it looked a lot like they were using rebar. Which is a steel and might explain part of their struggles. They were trying to cast at too low a temperature using an alloy not well suited for casting.

[@flamethrowex]

@@herscher1297 dumb question then... i know this probably wouldn't work, but i'd love to know why: what would happen if you set up a mold filled with mild steel pellets or filings, and put that directly in a kiln? or set a crucible with an opening at the bottom above to mold so that the steel poured through as it melted?

[@herscher1297]

@@flamethrowex tbh i dont see any reason why this shouldnt work. You would need a mold able to withstand the heat. Also, if you cast steel you will need to reheat it for tempering and quenching.

[@ghetorange9604]

They for got about the trapped air, a metal casting need two spouts or the trapped air would act like a stopper and cool of to fast

[@NathanNostaw]

There was a continuous reference to cast iron, but it looked like the metal stock being fed in was rebar. This makes it cast steel, dirty cast steel, but still steel. Being steel it will have much better capability to be cast, then forged and heat treated to a useable blade. The movies all show open casting, but not further working. We could assume they forged after the pour. Worth trying again, but next time with a furnace that can at least get good heat into a reasonable amount of steel.

[@rachdarastrix5251]

Oddly enough in the tv scenes I've seen after they cast it and let it cool they then heat it again and let it cool then heat it again and hammer it on an anvil then dip it in water.