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Tim Mitchell

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  1. While I enjoy the enthusiasm, the documentary didn't actually state anything like that. There is no evidence, unfortunately, that this source of iron ore ever was used in ancient times to produce crucible steel. The documentary showed that it "was possible" to have made crucible steel from this location, however the high sulphur content in the ore would have required the addition of manganese or repeated roasting of ore and ingots to get the levels low enough to forge well. They may have used this deposit for crucible steel, but there is no evidence that they ever did. I know one of the guys who was a part of making steel from the ore at that site and they are getting good results and good patterns from the steel, but have to give it extra treatment to help lower the sulphur. The presence of vanadium means little in this context. Vanadium has been lauded as the needed element for creating patterning in crucible steel, however this is not correct, at least for most crucible steel patterns. There may be one or two specific patterns that require some, but most of the crucible steel patterns are easily obtained with other Carbide Forming Elements. The history of the loss of the crucible steel industry in India is relatively clear although not widely reported. It had nothing to do with the changing of ore supplies which was simply a theory. It was multifaceted with the British wanting to control the production of weapons in the country in order to remain in power, and as a result controlled mining and steel production. They also wanted to be the main source of steel consumed in India and in the near east. By shutting down the export of crucible steel in India they guaranteed a market for their excellent quality British steel products. Deforestation was the main reason that they used for shutting down the main production center in the Deccan, the British also were reported to have killed entire Deccan steel making families causing the loss of hundreds of years of knowledge. Crucible steel was made in several locations in India, and there are accounts of people visiting them during this time period of decline. It was clear from the reports that it was both the deforestation issue and the British ban which caused the manufacture to die out. This is a great video and I am glad that Mike Loades was given permission to release the unfinished doco. I had heard about this from a friend who was at the funeral, there were also interviews which were not included, Al telling stories etc. I really wish that those had been released as well. Thanks for sharing the link here too.
  2. No one has done a detailed study of the edge hardness and geometry of the old blades as far as I know. Wootz / Pulad was used for scissors, kitchen knives, swords, armor, armour piercing daggers and punches etc. It was used for everything that we would use a tool steel for today. So yes there were different historical applications, but I know of no analysis of the steel characteristics in these different applications.
  3. There really isn't a difference in the quality of the steel from the different crucible steel processes, regardless of whether they carburised bloomery iron or decarburised cast iron, they all achieve a crucible steel between 1 and 2% carbon which is very pure and relatively free from inclusions. The Indian steel was better in most cases because of the lack of sulphur and ease of forging. What makes more of a difference in the quality of the steel is how it is forged. The strictly dendritic patterns have less diffusion of the carbide microstructure and can be a bit more brittle than a watered pattern. The watered patterns have more diffusion, finer carbides and are generally speaking less brittle. But the big part is to do with the final stage of forging. If you forge down through the critical temp you will get the carbides spherodizing and this makes the biggest difference to toughness and flexibility. If you do an air quench the blade will be very flexible but not as good at cutting as some other blades which have had a good oil quench. It is horses for courses, do you want a blade that is designed to cut steel or do you want a blade that holds a very fine edge geometry and lasts a long time? You can't have both, unlike the legends try to make out...
  4. There is evidence that they were able to look at the pattern of an ingot which had a window ground in the side and which had been lightly acid etched. They could tell how good the final pattern would be and perhaps the spacing of the pattern in the final blade. They were used to using ingots from a specific source and so the ingots wouldn't have changed too much for a particular smith, but when they changed to a new supply of ingots they would have to be able to verify the correct temperature range to forge in for their new source of ingots. It is part of being a master craftsman. Now not all would have been able to do that, only a specific group who had been taught how to make the best quality blades. The processes which added carbon did so to bloomery iron which would have been very low in carbon. The reverse process removed carbon from cast iron which had a carbon content of over 2%.
  5. Ok, back to the process... actually the processes as there are four distinct types of process that were used. Most of the processes used bloomery iron which was either produced onsite or was made at other locations and bought by the crucible steel makers. In India the caste system was very ingrained and there were people who only made different types of iron. Some processes added wrought iron and cast iron together, others added a larger amount of carburising organic matter to wrought iron, there was also a reducing process, however the two most common methods were the carburising process and the method of using cast and wrought iron. Most of the old processes from Persia used wrought iron, and plant matter which was high in tannins was added to the ingredients, sometimes shell or manganese would be added to clean the metal of impurities. This type of process would often result in an ingot in the high carbon steel range. Other processes would result in an ingot which had a higher carbon content and were more like cast iron. These required a time of long roasting in the furnace to lower the carbon content to a place where it could be worked sufficiently into a blade. Roasting of ingots served several purposes depending on how it was done. It was used to reduce sulphur in the ingot, to reduce the carbon or simply to anneal the ingot, but that also had the added benefit in giving the final pattern a higher contrast with greater spacing between the bands of carbides. Some ingredients would most certainly have been from the local area such as wood and sometimes iron, other more uncommon ingredients would have been bought from traders. All locations that I know of obtained organic matter from the location where they had the furnaces. Once the wood was used up they would have to move to another location. Some were near ore supplies, and others were needing to have others make bloom iron and buy it in. We have old accounts of towns which were well know production centers of bloom iron. In Salem, India the process that was used was to line the bloomery furnace floor with crushed quartz, then take the cast iron fragments of the bloomery process and melt them down into a molten mass of metal in this depression or massive crucible. The furnace was then run until sufficient carbon was burnt out to cause the steel to solidify and they would then remove the ingot and cool it with sprinkling water over it. This made a thin and rather wide ingot often with a shrinkage cavity in the middle and sometimes with quartz grains in the bottom of the ingot. Notwithstanding the many differences, there are some significant similarities in the different processes. Most of the processes required some form of organic carbon source and these were as far as I can tell, always very high in gallic acid and or tannic acid. The processes mostly used bloomery iron as an ingredient which contributed the phosphorous to the ingots, which most of the old ingots had in some level. The ore in Persia was high in iron sulphides which occurred as a white, yellow or greenish powdery seams on the iron ore deposits. This required them to add manganese to the melt, to combine with the Sulphur to produce Manganese Sulphide which then separated out as a flux. The ore deposits in India did not have this sulphur problem and so no Manganese was required to be added and the only trace minerals which were in the ingots were those from the ore, from the charcoal or the ingredients added to the crucible. Sometimes calcium in the form of shell was added to help to lower the phosphorous and silica content of the ingot through combining as Calcium Phosphate and Calcium Silicate which rose above the steel as slag. All our modern steel making techniques and understanding began through the study of crucible steel and our alloying processes and steel purging methods sprang from these ancient methods.
  6. Some blades did contain carbon nanotubes and it has been a much hyped element of discussion in the topic of Wootz recently. However we have no idea how many blades from ancient times contained carbon nanotubes and what the connection was, if any, to the legendary performance of this steel. It may have a bearing, and it may be more common, but that is no something that is known yet. Just having a good crucible steel with no nanotubes would have flexibility and toughness depending on the crystalline structure and carbide shape.
  7. Hi Alan, you raise a good point about welding of wootz. It wasn't uncommon to forge weld crucible steel, we see repairs like you saw and we also see chevron style blades where alternating sections of pattern welded steel and Wootz were forge welded into one blade. Al Pendray actually did this. The truth is that because of the higher carbon content that is in most Wootz blades, you have a lower welding temperature than normal pattern welded steel. You can raise a 1.5% Carbon Wootz blade with a good watered pattern up to 1100°C without losing the pattern. I haven't personally welded Wootz, I haven't had the need, but it can be done and isn't too hard from what others tell me. Using cast iron filings in the joint is supposed to help make the welding easier. Now to patterning.... in all crucible steels, ie. steels which have been allowed to be solidified undisturbed in a crucible, dendrites form. These dendrites are tree like structures of more pure iron which grow during the solidification process. The slower the solidification rate, the larger the dendrites will be that are formed. As the dendrites form, any Carbide Forming Elements such as manganese, vanadium and phosphorous are pushed into the spaces between the dendrites. These areas are usually called the Inter-Dendritic Regions or IDR for short. When the ingot has fully solidified and cooled we then have only the microstructure of the IDR left as evidence of the dendrites, there actually are no longer any dendrites at this stage, it is all steel. When we say that an ingot has a dendritic structure this is what is being referred to, it is this carbide shadow of the dendrites which gives the ingot it's pattern. This pattern is the foundation of the final pattern that we see on a finished crucible steel blade. But everything that is done to an ingot affects this pattern and can change how the finished pattern will display on the blade surface. Most of the old ingots contained high levels of phosphorous and some levels of sulphur making them more temperature sensitive when forging. The ancient makers often used to deal with this by roasting the ingots for long periods of time around their furnace which would remove carbides from the outside of the ingot making it easier to forge and less brittle. This roasting process also annealed the ingot and started a process of evening out the carbide forming elements in the dendritic structure (the IDR). This partly dissolved the branches of the "trees" and left more of the main trunks in the microstructure. This had the side effect of increasing the width of the banding between the final patterning bands of the blade which was a highly desired quality. Once the ingot was roasted enough it was then sold to merchants and the ingots made their way to the blade smiths. The smiths would then forge the ingot out into a blade and precisely how they forged it out determined how the final pattern looked. If they forged the ingot out at a low temperature then the IDR would remain relatively intact and so you would see a stretched and crushed dendritic structure on the surface of the blade. This is the most common form of pattern which we see today. If they forged the ingot up closer to the Acm mark on the Iron Carbon Phase Diagram (they didn't have a phase diagram back then ) the IDR would break apart more and it would look less dendritic and more of a watery pattern. For a long time it was thought that the ancients didn't forge above the Acm mark significantly, but when we look at the account of Abbott in the Punjab, he describes a smith forging an ingot at what would be called a bright yellow heat today. This ingot was most likely one from the Salem region of India. So we know that some smiths did go that high and from those of us who regularly forge at these temperatures, we know that the lovely open watered patterns come from forging at these higher temperatures. The smiths didn't have any way of knowing what the carbon content was in the ingot they were forging and they only used their eye to determine the temperature of forging, so the way that they would have been able to tell the correct forging temperature for any one ingot regardless of the carbon content, would be to raise the temperature and hit the ingot with a solid blow and observe how much of a dint the hammer made. This is a foolproof way to determine the correct forging temperature for an educated eye, and it is the way that several smiths today believe that they did it. The only way they could have done it. Forging an ingot at this temperature range causes the bands of carbides in the grains to line up and the rough dendrite bands become straighter and orient according to the plane of forging. We still have no idea as to how this happens although there are some theories. But this super straight carbide sheet structure only forms after forging at high enough temperatures in the early stages of forging the ingot. There are accounts of forging at lower temperatures, and certainly we see evidence of this with the purely dendritic patterns, and even the blades which were forged at higher heat to get the watered patterning were forged at lower heat in the latter stages, this is because we can see that the carbides are spherodized in the final blade surface. This spherodization is evidence that the smith forged around the critical or non magnetic temperature of steel (727°C) forging down to below this temperature spherodizes the carbides and increases the flexibility and toughness of the blade. There is another form of patterning which is often confused with the cluster sheet watered pattern, and this is the grain boundary pattern. This looks very similar, but on closer examination it is round loops which have been stretched and squashed together to create the patterning. This pattern comes from going slightly too high in forging and the carbides jump to the large grain boundaries. As the temperature is lowered and the grain boundaries are refined at lower forging temperatures, the ghost of the old large grain structure remains and is stretched becoming more visible and it diffuses (spreads out) into the appearance of sheets. These are the basic three types of patterning mechanisms, dendritic, cluster sheets and grain boundary. All are beautiful in their own right and are original patterns, and they all tell us how the smith forged out the blade. Whoops... there is one more pattern and that is ferrite / perlite banding which happens to blades which are below 1% carbon content. These patterns created the base for the main groups of patterning in the ancient blades. The ancient smiths used to use chisels and punches to crate ladder patterns, rose patterns and also shaped hammers to undulate the pattern sheets in specific ways, just like we do today with pattern welded steel blades. Some accounts claim that the smiths quenched the blades in oil, some (unlikely) claim a blood quench, others use an air quench. There are quenches using urine and others which claim to make the final blade non-magnetic... so we can't say that Wootz / Pulad was quenched "this way". There wasn't one way. Quenching in Air makes a perlite structure in the blade which is flexible and tough, but with limited hardness of the edge in most cases. Other quenches would create a combination of perlite and martinsite, which gives a good mix of hard edge and tough flexible blade. Wootz / Pulad didn't have one level of quality just as there are really good and very average quality blades today. The legendary qualities of the blades (probably exaggerated) came from the forging technique and then from the way it was quenched. Abbot was, among other things, a collector of crucible steel blades and he categorised the different blades according to quality, saying some were exceptional and others were very poor, he claimed that the Sham from Syria was the absolute worst for quality. There is an account in existence of how to restore the pattern in a blade with a poor pattern and the quenching stage was a perfect description of a quench from precisely non-magnetic. The ancient smiths, the good ones that is, were not to far from our knowledge of the proper way to heat treat a blade.
  8. The question probably should be "What is crucible steel?", but anyway... Wootz was a steel that was also known as Indian steel in past history. The original name wootz is an Anglicization of the word Ukku which means steel in one of the many dialects in India. There are many other words to describe steel in India, but this one seemed to be the one that stuck in the west. The word for the same steel in northern India and Persia was Pulad, also meaning steel and it's derivative in the baltic states was Bulat. Wootz / Pulad / Bulat was a crucible steel technology where ingredients were added to a crucible and a final ingot of steel was the result. Some times the process was a decarburizing process, other times it was a reduction process or a carburizing process. In one process it wasn't even in a crucible, but actually used the bloomery furnace as the crucible to make the cake of wootz, this was actually how one of the specimens which Joseph Banks sent to England was made. It most likely came from the Salem district and still had pieces of crushed quartz embedded in the base of the ingot from the furnace floor. Joseph Banks called this steel wootz as well. Crucible steel known by the names Pulad, Bulat, Wootz was made over a wide area and each specific language region had their own name for it. With the exception of the steel from India which was traded all over Asia being called Indian Steel. These steels were made in Mysore, Decanni, Salem and a few other places in India, it was also made under the name Pulad in Turkmenistan, the Fergana Valley, Chahak and other places in Persia. More places are being found periodically and many of the older sites have vanished to the point that we have little idea where it was made. The earliest examples of crucible steel with carbide patterning is on blades from around the first century AD. Some say the first century, others say the third century, but it is around that period. However there are textural references to Indian Steel or what we would call crucible steel back in the time of Alexander the Great and some claim it to be even earlier. It is claimed that the process was invented by the Indians and then perfected by the Persians. We must remember that the central Indian process at Decanni (Hyderabad) was actually overseen by the Persians and as I understand it, it was actually called Pulad by them. The ingots from Mysore and from Decanni were exported out of India and into Persia where the trade was controlled or restricted to the west. There are references to this trade as being massive in the 1600s and after. This steel was used by smiths throughout Asia to produce the wide range of patterns which we see from that time onward. There are many recipes from times predating this period, but it seems that after the 1600s most of the steel was produced in India and exported to smiths who made the specific patterns. There was still some being made in Persia, but the sheer quantity was not to be compared to the export from India. There was variation in the process over time even at the same location, but generally the ingots were made in a ceramic kiln type furnace where multiple crucibles were placed. The crucibles were raised to melting temperature over a long period of time (5 or more hours) and then sometimes allowed to cool outside the furnace and at other times allowed to cool in the furnace at a slower rate. The slower the rate, the larger the dendrites and also the more likely porosity would be to develop in the center of the ingot. The ingots were often then roasted for extended periods of time to soften them and this also helped to increase the width of banding in the ingots. One important thing to say is that Wootz is often connected with the steel produced in deep Southern India and Sri Lanka, this steel was in the form of rods or long cylindrical ingots. This steel never produced a significant pattern and the steel that we normally connect with being Wootz blades and Armor was in the form of cakes or bun shaped ingots.
  9. I second that. It would be good to move the discussion of history etc to another thread. The discussion has started to move off topic for this thread.
  10. You can't generalise with even production zones of Persia and India as there were many different patterns which came from these regions. The only thing that we can do is to accept that it all is Pulad / Wootz and then just categorize according to specific patterns and perhaps the century. This is the way that the old writers described crucible steel in the old days and I think we need to keep with their method instead of saying that this or that isn't wootz or pulad...
  11. There is some confusion about this. The truth is that Pulad means steel in the Persian language, Bulat comes from the same word meaning steel, Wootz comes from Ukku which was a local word meaning steel in one dialect in India. It simply meant steel, nothing more nothing less. Sometimes it was called "Indian Steel" if it came from India. But the way the ancients designated between the different types of steel was to refer to it by either the maker, the region of forging or mostly by the pattern. It was always classified by the pattern and that was broken down into the background colour and the nature of the watering or specific pattern. The pattern that Verhoeven talked about and was seeking to get was the Black Wootz or the black pattern from the Khorassan province in Persia. It was a highly sought after pattern and that is why whey were trying to reproduce it. It was all called Pulad / Bulat / Wootz and much of it was made from ingots which came from Mysore or Decanni in India during the 16th century onwards. However regardless of where the ingots were made, the final blade always bore the name of the location where it was forged or the nature of the pattern. Hence it is acceptible for us to call a piece of crucible steel Wootz or Pulad etc. regardless of the pattern but it is good if we can also categorize the pattern.
  12. I know what you are saying, but the problem is that the composition was so varied and there is no common composition... none. The internal structure of the blades also is different between cluster sheet patterns, purely dendritic patterns and grain boundary patterns, so there is no common internal structure, only commonality in specific groups. Even the ingots that came from Decanni were forged out in many different ways and many different patterns were obtained from them. So there is no classification that we can use to say that something is or is not a correct reproduction of crucible steel in a general sense. We have to be specific as to what we are trying to reproduce and frankly the precise composition is not as important as you may think.
  13. There is research which shows both dendritic structures and cluster sheets and both of those are historical varieties of crucible steel. JD Verhoeven and Al Pendray documented only one form of crucible steel, the Black Khorassan pattern from Persia which was actually called Pulad not Wootz.... just a technicality. Scientific research has only shown us that carbide forming elements are needed, that in some cases there are carbon nanotubes, and that there are spherodized carbides in quite a bit of the ancient steel. Vanadium is not present in all watered pattered steel, but there is always a carbide forming element... usually many. The scientific research does not in any way show that crucible steel must have specific characteristics. It only has shown some of the characteristics that some very specific patterned steel from some regions contain. The only comparisons that we can draw outside of the shape of the carbides and the presence or absence of cluster sheets, is the pattern itself. If the pattern matches and the carbides are spherodized, we can call it a reasonable reproduction of any specific pattern. I am a researcher and have been making crucible steel for 15 years, and there are many on this forum who have been making it longer , and I can tell you after knowing the scientific researchers personally, that not all you read is actually the full and precise truth, especially not representative of even the majority of crucible steel blades. Do not worship the research or the researchers, take what they have to say and realise that it is specific to a specific group of blades, and know that we have not even examined a needle in the haystack of all the existing crucible steel blades out there. The composition of blades varied so greatly that we cannot do anything except generalise about the total body of crucible steel examples. They contained copper, silver, manganese, vanadium, chromium... all in different amounts (or none at all) in blades from different regions and different times. Crucible steel was made in many different locations using just as many or more recipes, and was forged out in even more different ways by so many different smiths and over close to 2000 years. So when anyone tries to make generalisations about crucible steel, bulat, pulad or wootz.... I just smile and shake my head. Keep reading what others write and know that half of what they write is not correct, eventually you will start to get a clearer picture and shake your head too .
  14. Actually we have to be very careful to not talk in generalizations concerning the old steel and patterns. There are many different patterns which we have from old blades and some are very easy to replicate, others very difficult. When making comments about difficulty or ability to reproduce crucible steel we must be specific about what pattern, what region, what method, what time. Suzdalskiy could you please explain your comment about "getting an analogue".
  15. Marius, you clearly don't know wootz sufficiently to comment. A bar can easily show a very good pattern after filing, light sanding and etching, and one doesn't need to make a blade from steel in order to show that they have a good pattern or are legit. Being able to forge out a bar into a blade doesn't reflect on the origin of the bar in any way, you can still take an old bar and forge it out into a new blade and it still isn't your material. So your comments are baseless, illogical and show ignorance. Niko is one of the best as Alan said, he also has published his technique in an international journal and he has done the hard yards to get where he is today. Why was your first comment an accusation of fraud instead of simply one of wonder at the quality of patterns which he was able to achieve? Where are your steel patterns which qualify you to be able to criticise, where is your proof of experience in making wootz?
  16. Hi Athan, Good job on the blade, it is a pity that you lost the pattern a bit at the end. It is hard to tell from the picture, but from what I can see, you probably turned it all to martensite which as Niko mentioned that it masks the pattern and makes it dark. I have had this happen on some blades, the pattern is still there, but it creates a ghosting of the pattern when you etch it. Also each time you do a heat treat in the forge, you have to take the small layer of new decarb off the surface of the blade or it will hide the pattern. You can still etch it deeply and show pits where the pattern was, like a negative of the pattern, but the carbides are gone and you have to sand past that in order for the pattern contrast to come back. Hope you have better luck on your next blade. Regards, Tim.
  17. You seem to be having more success with your ingots now Jan, well done. Your experiments look interesting, I am curious to see your results. Keep up the good work.
  18. Hi Andrei, Considering your experience you will have no trouble stepping into making crucible steel. I agree with Mark, there is plenty of information out there and in this thread to help you get started. There really isn't much to getting a usable ingot that can be forged out, it only gets hard when you try to make your own crucibles or move away from the standard ingredients and methods that are in this thread. Using standard ingredients (meaning with known analysis) you should be able to get a usable ingot the first or second time. This is so long as you: - Use Clay Graphite crucibles or Silicon Carbide - Keep your furnace atmosphere slightly reducing not oxidizing. (an oxidizing atmosphere can cause bubbles around your ingot base and higher nitrogen content in the steel and therefore a more brittle ingot) - Don't get the melt too hot or you will get porous areas or bubbles inside the ingot - Make sure the ingredients are fully melted (dip method works well in conjunction with an optical pyrometer for repeat-ability) - Keep your calculated carbon level between 1% - 1.5% (beginners have a hard time with high carbon ingots) - Add a bit of Manganese to the melt (helps with forging and with pattern - almost all old Persian recipes added some manganese) - Don't try to do a realllllyyyy slow solidification (too slow causes a fragile ingot especially for a beginner - 1 hour is fine to handling temp) - Do a good roast of the ingot for between 1 and 3 hours before you forge the ingot (to normalize and decarburize the ingot outer layer, should be done in a neutral or slightly oxidizing atmosphere but not for too long if oxidizing or you will pull too much carbon out of the ingot) Once you have a good ingot: - Forge slow at first and not too cold - For the beginner keep the temperature around 950°C for 1.5% Carbon or 800°C for 1% Carbon while forging (this is a safe temp for a standard dendritic pattern in crucible steel with little risk of getting it too hot. Any porosity won't close at this temp, the steel will end up slightly more brittle than forging at higher temps and you won't get the woodgrain or watered patterns that come from the carbon moving more freely in the steel) These points should help you to avoid the common pitfalls that trip up beginners and to be able to get success not long after you begin. Perfecting the making of crucible steel can take a lifetime and is lots of fun, but you can get some workable steel without too much trouble and with a bit of advice. It is much easier these days than when I started out 15 years ago, there is a lot more information out there now and some really good guys who will give you advice when you get stuck. All the best with your journey, Tim.
  19. Very nice pattern Suzdalskiy! Thanks for sharing.
  20. Thanks Krzysztof for sharing your pictures of the steel. Can you share about what temperatures you used and what carbon content you were aiming for? You have some dendrites visible in the final pattern, so it looks like you were forging below the Acm temperature level for most of your forging process. It also looks like you gave it a good roast or soak time before forging, is that correct? About the etching, if you want a more durable etch, you can always do the reverse etch that I often do... it isn't traditional, but I heat the blade before the quench in an oxidizing flame which pulls carbides from the blade surface and decarbs the surface layer just a bit. When etched these microscopic pits become larger under the action of the ferric chloride. This makes the surface steel the shiny part and where the carbides were becomes dark. It is a much more durable layer though and significantly more rust resistant, although it does mask some of the natural beauty of the wootz. Kind Regards, Tim.
  21. Thanks for sharing the pics Klaas! looks like fun was had by all.
  22. Awesome Karl! I am sure you will have a great time. Ric is a great guy and apart from being very knowledgeable, is good at sharing what he knows. Look forward to seeing you producing some of the good stuff down the road. Tim.
  23. Hey Jan, good work with your experiments! You got some nice sized gas bubbles in the ingot there, perhaps if you added some calcium or a tiny bit of Aluminium to the charge it may help with removing the excess oxygen from the ingot so it will be bubble free. Sometimes rust can cause bubbles in a melt. Also new crucibles have the ability to do that as well. Looks like you are doing some very interesting stuff there. Well done. Tim.
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