First solo Tamahagane smelt

[vincentmarche]

I appreciate all the tips I got from people in the forum!

65 lbs magnetite

200 lbs charcoal 

total burn time 6 hours

approx 3-4 lb charges every 10 min

 about 30 lbs bloom

 

 

[DanielC]

Good job. Now spark test everywhere you can, and then work it down into bars. Both excersizes will reveal to you if the furnace was ran according to its size/dimension for either iron or steel. It can also reveal slag health and how much of it is with your iron/steel which is important im bloomery.

[vincentmarche]

Yes Sir, thats my project for this upcoming weekend.  I'm hoping I did things correctly.. Either way it was a fun experience.. although I do have a "ash burns" on my neck and arms to remember it by

 

Edited November 6, 2018 by Mod34
Excessive quoting

[Sly]

How many pounds was your returns?

[ThomasPowers]

Don't know if he's reading this so I took the liberty to copy his info from the original post:

65 lbs magnetite

 200 lbs charcoal 

total burn time 6 hours

approx 3-4 lb charges every 10 min

 about 30 lbs bloom

[Sly]

Well rough parts lose alot of their mass due to slag and crap falling off when roughly consolidated so normally youd weigh that after being roughly bricked.

The bloom weight couldnt be said to be a true return.

[ThomasPowers]

And you could say that neither is muck bar, merchant bar, singly refined, doubly refined-----only tripply refined is the one true return weight.

Most people I know weigh the bloom vs the inputs to get return and pound bloom per pound charcoal too.

This also seems to be the case in all the academic papers I have read on the process.  Who all uses muck bar weight?

[Sly]

Ah lol. I just count it by whats refinable.

[ThomasPowers]

Perfectly sound method---for you and your uses. As I told my new student Sunday: "In all blacksmithing processes there is only ONE correct method of doing it---and that is ANY WAY THAT WORKS!"

[eseemann]

Good Morning All, 

Please correct me if I am wrong in my understanding of the process used to make this bloom in to a blade. As I understand it the sword smith or any other type of smith would take the bloom and flatten, fold, weld and repeat. What I think I understand about this process is that all the smith is trying to work all of the crud (for lack of a better term) that is not iron out of the material using the process of flattening, folding and welding. I assume the mechanic that makes this work would be due to the fact that the aforementioned crud is brittle and would not weld due to being an incompatible alloy.

On a side note I assume you could braze slag to steel or iron but that is not the same as welding. 

How am I doing on my understanding?  

Nice work.

[JHCC]

As I understand it, the main point of repeatedly flattening, folding, and welding the tamahagane is make the carbon content consistent through the entire bar. With bloomery iron, the point is to consolidate the bloom into a single mass; the slag that remains within the bloom becomes the silica content that gives wrought iron its fiber-like grain.

[ThomasPowers]

Remember forge welding cycles LOWER the carbon content of your material.  They also refine the size of any slag inclusions and lower the total amount of slag withing the material---compressing the billet with the hammer tends to extrude molten slag that has a pathway to the surface.  So you have a balancing act: Carbon Content vs Slag amounts/size of inclusions.

Randomly folding will not result in the best material. You need to know what's going on as you do it!

[JHCC]

It occurs to me that if you made a small fish from scraps from Japanese swordmaking, that would be a whole different kind of tamahagane smelt.

[Steve Sells]

OUCH that pun is painful

[Sly]

There are so many different methods to even work the material..

I think the simplest way to explain it would be that the goal is to engineer the microstructure of EACH part of the steel.

Idealistically youd refine batches with different properties and mix them until you have something like tree rings, each layer on the tree contributes something just a little different but it still acts like a single unit.

The main goal regardless of country is to defuse shock since it passes through each material differently as well as other properties but the truth is you end up losing half of your content that you typically have to mix it, and then fold that until it will heat treat acceptably. Mixing batches helps with the refinement process too, you could say fold the billets only 5 times mix them and then refold 6 times to get each layer to the requirement of 11 folds to be refined. Its as complicated or as simple as you want it to be.

Not to mention alot of the surviving blades had single layers that were counted in the thousands to ten thousands presumed to be reused swords, european or japanese.

Such a broad topic anyways its hard to sumerize.

 But the real wonderful thing is if you fail you can just undo the heat treatment with a long austenization and refold till it works, probally happened alot.

[Buzzkill]

5 hours ago, Steve Sells said:

OUCH that pun is painful

Not from my Perch.  It's just a little fishy.

[Steve Sells]

I dont trout dat

[ThomasPowers]

Are you all just going to flounder around making fish puns?

[Buzzkill]

I was just doing it for the halibut.

[Frosty]

Fish puns. How old school.

Frosty The Lucky.

[Steve Sells]

seems a few of us took the bait

[ThomasPowers]

You mean they fell for it Hook, Line, and Sinker?

[Steve Sells]

not that hard to swallow is it ?

[Buzzkill]

You swallow all that and you're going to need  a sturgeon.

[JHCC]

There's a time and plaice for everything. That's as plain as a pike-staff.