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Jan Ysselstein

In Search of Hamon, Experiments at the Forge #1

89 posts in this topic

The above bars were reworked,

Bar showing pattern ( wootz/wrought) was split down the middle and each half was widened a bit.

The crucible bits bar showing no pattern and no carbon contrast (?) was folded a few more times ( lost some material but should get 1 quench out of it). I am losing some material because I am forge welding all handles to the bars.

The plan is to finish the thread with the high carbon bloom material ..have some decent hamon and Exit...I am still working with clay as a flux and hope to will finish that as well.

Edit,

The clay/straw ash  welding process  worked  ..I was able to weld a file back on itself( after modifying the clay several times ). This is turning out to be a very interesting process and at some point I will do a bar using only this process..at this point it served more as an understanding tool. Variables are not just related to the clay.

Jan

Edited by Jan Ysselstein

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I have started the refining and welding of high carbon bloomery iron and will try to do about 12 folds before shaping the remaining steel into a tanto. The welding of the first bar with straw ash as flux worked pretty well . Here is a picture of that first bar before  doing any folding. The welded bar still sparks as high carbon.

DSCN6125.jpgconsolidated bloomery iron

Edited by Jan Ysselstein

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I have been processing ( consolidating ) some high carbon bloom into bar stock and need to reduce it to wafers before moving on. The bar stock folding will result in a blurry steel color , which I want to avoid. For now I will stop and build another furnace as the exterior shell is turning yellow during the welding process. Here are a couple of pics.

A bar cut and broken ( that is a slag burn on the hand ), flattened consolidated bar quenched and broken ( I am still looking for the ones that flew away)

The cut bar break was hit with a rotary wire brush.

DSCN6138.jpg

Consolidated ( flattened ) high carbon bloom.

DSCN6139.jpg

Edited by Jan Ysselstein

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I have to take advantage of the seasons here and open fires are not allowed after April 30. Rice straw ash is becoming an essential ingredient in the welding of iron ...today I converted a bale of straw to ash.

 

Edit:

The yield of this run if expressed at % of ore weight was 47% 

The yield if expressed as total iron added    was 65%

All metal, slag and fluff was recovered and will be recycled as "ore" the cooled charcoal is ready for reuse as well. Next time we will try for a high carbon bloom... .

Cast iron bloom with viscous slag layer on top

DSCN6184 (1).jpg

Bloom profile showing bottom of furnace shape

DSCN6186.jpg

Bottom of the bloom, very little entrapped charcoal

IMG_3444.jpg

Slag and trapped  cast iron..most of the cast iron was in the shape of smaller prils 

 

IMG_3449.jpg

IMG_3456.jpg

It took a while for me to figure out how to reduce the smoke

IMG_3463.jpg

 

Amazing material having so many uses..I form it into a powder..while in use it continues to burn and becomes a true ash. I have not noticed the benefit associated with having the carbon in the charred straw ..so I use the ash as well as the charred straw.

 

IMG_3465.jpg

! bale makes about 25 gallons of ash and will last several years..age and the absorption of humidity seems to make no difference

 

IMG_3466.jpg

Edited by Jan Ysselstein
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Looking very much forward to this

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Jan, typically rice straw ash is used. It is suspected it is used because of its high silica content, up near 90% silica after it becomes ash. This silica is not present in other straws, as I suspect the minerals are absorbed into the straw due to it growing in partial flooded water.

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Thank you Daniel...I have done lots of tests with that material...amazing stuff.

The cast iron bloom in the post above will be repeated in the next two days. I will try to shift some variables to get closer to the goal of making an easily reproducible high carbon bloom. So 30  lbs of ore is ready and 1.5 hrs of run time should give us rate of .33 lbs per minute. Though that is good clip, I have done over 60 lbs per minute in previous runs.

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Jan, could you post a pic or two of your furnace? I think you said you were building some new forges/furnaces etc.

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Joshua,

   I have some pictures of a forge build very safe  and very hot.......I will post them in a day or so. I have a video of how it works but I do not know how to post it. When I choose it from my desktop all it does is show the file name.

 

Edited by Jan Ysselstein

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Got the chance to run another furnace last week and the iron looks good but the yield is low.I am using old charcoal and got into some pretty small material and ashy material. This is one of my attempts at adding slag to the mix..the charcoal got me into trouble....  

I will use this bloom ( very high carbon , very bright but no colors ) in the next few posts here to see if I can fold it.

Bottom of the flat bloom and a foaming slag mass found on top of the bloom 

IMG_3025.jpg

 

Foaming slag, showing small charcoal

IMG_3040.jpg

 

Broken bloom 

IMG_3047 (1).jpgIMG_3043.jpg

Edited by Jan Ysselstein
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Curious about the carbon content of the above shiny bloom. Here are some pics after a rough grind..not quite cast iron but way up there..my guess is close to 2.% carbon. I will try to forge it after a long 2 hr soak in slag ( the foamy slag shown above + a little borax) .frame5.jpg

Edited by Jan Ysselstein
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Soaking the above flat high carbon bloom for almost 2 hrs , occasionally adding borax, worked ..I tested a section and was able to compact it vertically but it has no strength side to side...it should stack and come together.  My new forge/crucible furnace is done ( very simple ) and I hope to weld some more this week end. The bubbles forming under the borax are carbon monoxide ( CO ). If my metal sample were to weigh 500 grams and be at 2.4 % Carbon and I wanted to reduce that carbon to 1.2% Carbon...then I would have to lower the carbon by 6 grams. The volume of CO generated by 6 grams of carbon would be about 3 gallons of CO at room temperature  ( patience). Adjusting for temperature difference at the forge temperature that would be almost 5X as much in volume.

 I have made some charcoal ( Pit Charcoal ) , about 275 gallons and due to my fear of small particles I will probably only be able to use 1/2 of that material. 

Edited by Jan Ysselstein
additional info.
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IMG_3609.JPGIMG_3609.JPGIMG_3611.JPGI liked the last bloom material in the previous post ( it has potential and is very easy to process as a bloom ) so I attempted to make some more. That is it for me this year lots of oroshigane coming up on older blooms. Here are a couple of pics of the last bloom which is just a shade lower in carbon than the one shown above.

IMG_3608.JPG

I don't know why the text moved on me but it is up there somewhere

Edited by Jan Ysselstein

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So, taking a look at the microstructure , I think we have too much carbon...but going directly into a crucible as wootz may work. I will try to weld this material after decarb. treatment. I will test some clay welding slurries this week end..

frame6.jpg

 

Edited by Jan Ysselstein

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