Primitive Technology: One-Way Blower Iron Smelt & Forging Experiment

The new blower produces more iron than the previous one. Using the same amount of ore and charcoal, a similar sized furnace and the same bloom processing method it makes 51g as opposed to 31 g of the previous design. The continuous blower is a big improvement over the intermittent spinning design (and this was only the first try). It's the most iron I've made in a single smelt yet. The attempt to form a forgeable bar was disappointing although it was a better than expected casting. In the past I had successfully made forgeable iron by melting the prills in front of a blast rather than making a casting first. I will probably follow this method of decarburization rather than low temperature annealing in future. The waste iron isn't lost however, I should be able to recycle it in future smelts as I've got a small pot of it. The waste iron from experiments could be re-smelted alone or added to future smelts to increase the yield.

Jesus, with all this work for not even a single decent Iron tool yet, No wonder why it took so long for us to reach the iron age. Mad respect for all that dedication.

The dramatic arc from "It crumbles" to "The iron can be recycled by adding it to future smelts" is phenomenal.

I have a fair ammount of blacksmithing experience under my belt and forge welding different steel types together and I can't help but think that when you placed the iron balls into the clay form that using a form of flux to keep the oxygen off of the iron balls could help it keep from braking apart after you puddled it. Sand works as a decent flux because it will melt down I to a crude form of glass and even with extreme heat, won't allow the oxygen to it causing iron oxides that basically make a layer between the iron balls that will make it break apart when heated again. I have used plain old creek sand to forge steel together before and it worked just as good as Borax in my humble opinion.

Two ideas for a hotter fire--- 1) Insulate the firebox by adding a second wall 10cm away from the existing furnace wall. Fill the gap with loosely dropped in ash (not packed). 2) Preheat the air before it goes into the furnace (or into the blower). Maybe have a longer pipe going from the blower to the furnace and have a secondary fire under it to preheat it. Best of luck, each video is super exciting!

My heart when it shattered 😭For a golden moment, he had the best looking ingot he's made yet. But alas, success is not monumental, it's incremental! Godspeed, mud man.

Oh man, that first "clink" of the iron when it came out of the mold made it all worth it, it's been amazing watching this journey!

I subscribed to this channel six years ago when he was in the stone age and now he's in the iron age. He's going pretty fast.

The best part of every video is watching him start a friction fire with just his hands in under 30 sec. I’ve timed it, incredible and under appreciated. 🔥

That moment 19:47 when iron hits the rock and you know, you just know, this isn't a sound nature makes, this is the sound of civilization

As a metallurgy student this is really impressive. The blower has come a long way since your initial attempts. 2 improvements I could think of would be adding a flywheel to the axle and using the rope for a pulley drive with a crank handle. As an alternative you could also try Japanese style box bellows. Basically just a big square piston pump. For the smelt itself: the single biggest leap was hot blast. Basically just preheat the fresh air before putting it in the furnace. Ideally the preheat would be done by burning the exhaust gasses in a regenerative heat exchanger. For your stone age setup, you could simply run a clay pipe through a second fire between the blower and furnace. In ferrous metallurgy there is relatively little headroom temperature wise so even a few 100 °C of preheat should give you a significant improvement both in ore reduction and remelting. For your blast furnace you could also try adding a little limestone (snail houses/ egg shells) as flux. In principle all these processes benefit from upscaling but I doubt you want to do that.

You know you’re watching quality content when you don’t want it to end. Best channel on YouTube, hands down.

Some notes: more "modern" (meaning medieval) bloomeries were built a lot higher and torn down, while still hot. The bloom was then taken out of the bloomery while still hot and immediately compacted, so that the slag was driven out and an ingot was formed. Also during the smelting (although you don't really reach high enough temperatures to turn the iron liquid) the slag was allowed to flow out through holes on the base. That is why in German this type of furnace is called Rennofen (rennen/rinnen - Ofen = flowing - kiln/furnace). I would try to purify the ore a bit more (so no ash) and to seperate the slag from the iron during the smelting. Good luck experimenting further. Also one more thing: during a visit in Spain I was able to see a iberic smeltery where they also siffed through sand and water to seperate small ironore particles out, which they then smelted down in bloomeries.

I will never tire of the unedited one-shot of him making fire by primitive means with such efficiency. Everyone else I see try to do something similar has to use a cut because it takes them so long.

Seeing that bar of iron, after all the work I've seen go into it over the years, is one of the most satisfying things I've ever seen.

I appreciate that nothing he makes is so precious to him that he's not willing to break it and try again. After taking so much time to get that much iron, trying to forge it seems like a big next step. I think if something took that much work I wouldn't want to break it. But he builds and rebuilds forged trying to make them better.

I hope this channel continues through the ages. I hope to eventually see him create his own electrical system. It would be really cool for follow it that long.

Massive respect for all the unknown inventors of humanity, that developed many tools and methods before they could be eternized in books, stones or statues.

I'm not a metallurgy or mechanics of materials engineer by any means but i have studied it in classes associated with those subjects while getting a degree in mechanical engineering. These videos are a blast to watch and he's on the right track to making a forgeable iron if that's his goal. He's basically made pig iron which has a pretty high carbon content of typically around 4%. Carbon serves two purposes in this application. It allows the metal to reach a higher temperature for refining (which is how he was even able to get a solid bar of iron in a freaking charcoal furnace to begin with) but it doesn't allow the pig iron to be ductile and malleable for forging. The other issue with pig iron is it has a crap ton of impurities in it which are also messing with the composition of the iron being forgeable. Now if he is trying to forge this iron, he doesn't want a high carbon content and he wants the least amount of impurities as possible because what will happen is when he goes to hit it (to shape and form the iron bar), it will just crack and break. Which is exactly what happens in the video. He needs to essentially lower the carbon content of his iron that he has created and remove as many impurities as possible. This is where things get a little tricky. There are some pretty extensive and time consuming processes for lowering the carbon content so that might not be his next step. I think he needs to go through a purifying process. Without going too crazy into the material science and mechanics of materials aspect of things, i would say his best bet is to use a flux to help remove impurities. The impurities form slag that can then be removed from the iron that will become somewhat more "pure" then before. Getting the iron to a higher temperature (melting point is ideal) the flux will more easily remove impurities versus a white hot bar. shells are honestly not a very good flux material because of their chemical composition which is consistent in what he has seen in previous videos. But limestone (aka nature's "chalk") is actually kind of a perfect flux in this application for pig iron if he's trying to stay consistent with only what's in nature. The specific chemical composition of calcium carbonate (limestone) can be used in refining pig iron and extracting the impurities from the iron itself. I think if he is capable of getting his hands on limestone (which i don't see why not, its a pretty common sedimentary rock) and somehow getting his furnace hot enough to actually melt the iron (rerouting hot air possibly?) and maintain the heat, I think he can refine the iron to become more forgeable. Ideally if he had a larger crucible and more iron, with the flux, physically scooping out the slag (or impurities) that float to the top would be his best bet. But i don't know how feasible it would be to skim the top with the setup he has. I think coating the iron bar with crushed up limestone(as fine as he could possibly get it) and then letting it cool down to extract the slag and repeating the process maybe a couple of times could get the results he's looking for? The problem is, if the iron isn't molten the limestone could produce poor results. The idea is to get that limestone as incorporated as possible into the iron itself so it can react with and separate those impurities in the iron. Maybe instead of covering a bar with limestone, make a crucible that can increase the surface area so the limestone can be incorporated as homogenously as possible? I'm thinking a really thin iron plate? Maybe the bar is totally fine? Even agitating limestone into a semi-molten iron with a ceramic rod could be enough to get the results of processing the pig iron? Just a thought. Let me know what you all think?

My dad and I have been watching your videos for years and have been excited for you to attempt forging the iron you have been collecting. This channel has been a highlight of YouTube for years. Thank you for continuing on and sharing your journey with us! It’s been amazing to watch unfold. ❤