Iron smelting. Bloom extraction and processing in the forge.

In this video, I show iron bloom extraction from the reconstruction of the roman period bloomery furnace. This kind of furnace is called a slag pit furnace. In the smelting process, we used 20 kg of hematite ore and 20kg of charcoal (charging ratio 1:1). After the extraction bloom has been compacted using a wooden mallet, the iron at this stage is still not suitable for forging items and requires an additional process of purification, what is done in the hearth.

[@akord1328]

Oglądałem ten proces wiele razy. Zawsze z przyjemnością. Widzę postęp i narastające doświadczenie. Gratuluję serdecznie . I trochę zazdroszczę.

[@mattl3729]

Wonderful! Another really fascinating video Maciej- thanks! I'd just love to try making iron and working with it like that- maybe one day. Until then, thanks for letting us share in the experience with you!

[@tataedc6401]

Super że trafiłem na ten kanał i już zostaję :) Czekam na więcej.

[@user-jr2ue9nu6y]

That man is brave. Bare legs and hot iron. Forging in "short pants" and short sleeve shirt is no joke LOL

[@user-jr2ue9nu6y]

I was just about to say if you going to consolidate that iron with just a hammer. Strength and Honour. Glad you had a power hammer.

[@fear-the-phantom]

Amazing. Was a nice addition to see how you treated it after it cooled down from the smelting. Did they use some kind of machinery or just manual hammering?

[@officinaferraria]

Manual only. Water power hammers started at beginning of the second milenium.

[@Afro408]

Great job again and a lot of work for a little lump of iron. What wood do you use for your charcoal and how do you make it? Could you show us please? Thank you again for posting.

[@officinaferraria]

I use oak and pine charcoal. I do not make it my own, i buy it.

[@rodonsynheliosa]

The color and structure of bloomery iron after purification is so beautiful. Waiting to see what will You do with this iron 🙂.

[@officinaferraria]

Może ulberht z Ostrowa?

[@rodonsynheliosa]

@@officinaferrariaByłoby super 🙂

[@officinaferraria]

@@rodonsynheliosa taki jest plan

[@rodonsynheliosa]

@@officinaferraria Będziesz robić dla muzeum, czy może na zamówienie? Nie wiem, czy mnie będzie stać, ale wstępnie byłbym zainteresowany. Ewentualnie w wersji z innego materiału, jeśli będziesz mieć ochotę i czas. Pozdrawiam i do usłyszenia! Odezwę się na fb.

[@GreatSallet]

I'm very curious on the bloomery process, when do you know that it's the right time to break open the furnace and extract the bloom? Do you just wait a certain amount of time or do you look for specific signs that the bloom is ready?

[@officinaferraria]

The process is stopped when the furnace is full of iron bloom and no more ore can be added. Furnaces I use can consume a max of 40-50 kg of ore but the process can be stop earlier like in the video where we finish after 20 kg of ore.

[@kzarnold3678]

That's amazing

[@user-jr2ue9nu6y]

Love the Medieval shoes🤣

[@kzarnold3678]

Interesting stuff 🤔

[@dosgatosdesignsllc848]

NIce material from that smelt and a great job on this video. Any idea the carbon content? The sparks were plentiful during the forging

[@officinaferraria]

Carbon content in this material is about 0.1-0.3%. The sparks visible during forging were cast iron. The aim of this smelting process is to get soft low carbon iron but just in the front of the blowing pipe where the temperature is the highest some cast iron forms. The bloom rafination in the hearth, causes burning cast iron.

[@tiresomekarma4054]

I don't think I've ever seen a Roman period bloomery furnace, I've been researching a lot into making my own wrought iron and I was wondering if you know how to keep a piece fibrous? I'd assume I'd have to not consolidate the piece as much as you've done in this video.

[@officinaferraria]

In Poland where I live there are plenty of remaining of ancient furnaces (as a slag blocks). The presence of fibrous is a result of inhomogeneity in the structure and chemistry of the iron alloy (slag inclusions and strips of P-iron.) This time I used very good quality hematite ore, so there is no P in the alloy.

[@tiresomekarma4054]

@@officinaferraria I was also wondering if it's better for iron ore to be more fine like sand or to have it be in larger clumps around the same size as the charcoal you'd be using for smelting the iron

[@ostrogniew]

​@@tiresomekarma4054 in this process sand-sized ore grains are preferred.

[@Iron26.55]

Se puede convertir el hierro fundido en acero?🤔 y si se puede como se hace

[@officinaferraria]

El material que fundí en el horno no es hierro fundido, es acero bajo en carbono.

[@DarrellatWareham]

Curious as to what makes this specifically a Roman era furnace? Construction appears to be pre made bricks mortared with clay? What kind of bellows is being used (and what evidence)? Tuyere details? (Asking as a fellow iron maker)

[@officinaferraria]

Hi Darrell. Ancient furnaces have slag pits - hole beneath the shaft, the length of the pit is the same as furnace dimiter. During the smelting slag flow to the pit and form slag block ( i am sure u saw slag blocks collection in Pruszków museum in 2016, we also run with Kamila two slags pit furnace during festival). In Poland clay bricks and clay strips have been used to build furnaces. Tuyeres have been used but rather outside the furnaces. We do not know what kind of bellows were used probably primitive bag bellows.

[@jonajo9757]

​@@officinaferrariaHow many folds do you do when consolidating a bloom into a finished bar?

[@officinaferraria]

@@jonajo9757 it depends of the quality of the bloom. Sometimes 1 is ok, sometimes 10 is not.

[@jonajo9757]

@@officinaferraria Do you have any sources on how iron was consolidated? Preferably anything regarding the medieval period.

[@officinaferraria]

@@jonajo9757 using slage hammers, we know from Scandinavia 4-8 kg hammers. It is enough to make nice consolidated iron bar from bloom.

[@RovingPunster]

8:02 The billet looks slightly overheated to my admittedly untrained eye ... it was white hot and throwing sparks even before being hammered. Isnt there a fine line between forge welding temp and burning the steel ?

[@officinaferraria]

it is low C material, it needs to be white hot to weld it well.

[@RovingPunster]

@@officinaferraria Ty for explaining to a noob like me. +1 😁 Was there a step you did later on to boost the C content ... say, doing a blister steel step before restacking ?

[@user-jr2ue9nu6y]

Can you do a Damascus billet build from Bloom till final using traditional methods please? Yes ALOT of hard work. But would be an awesome video.

[@officinaferraria]

I've already done it here: kzbin.info/www/bejne/Z5eqk6SYZcp5eLM and here: kzbin.info/www/bejne/j6K3mKesjK-FrKM

[@박민제-h5g]

Achievement unlocked: *Acquire Hardware*

[@user-jr2ue9nu6y]

Funny how we take modern steel for granted when 300 years ago Men had to do this likely daily to make just 1 iron billet.

[@СергейСтарцев-ч4э]

Класс!

[@Julez3133]

im curious why do they always hit it with a handheld hammer a few times soflty right before they go plow the fuck out of it with that machine, does those tiny little taps even do anything in the grand scheme of things?

[@officinaferraria]

There are always some tiny parts of the bloom which should be "glue" to the main one before main compaction.