I've just been watching this video by an Indian crucible manufacturer, they use a screw type press to mix the clay and graphite into a homogenous mass with the operator at one point is shoving his arm into what is essentially a giant mincer to feed the mix in for a second time. There's a guy with a steel mould and mallet pressing the soft clay and trimming the excess before popping it out of the mould where it slumps noticeably. The next shot shows further smoothing of the familiar crucible shape so I guess they let the earlier soft crucibles dry a bit and then remoulded them into the proper shape. The dry crucibles are dipped in a glaze on the outside and then stacked in one layer of a brick kiln, though the kiln looks a bit basic, the circular single layer is going to ensure even heating and they are burning hardwood for the fire below. The firing takes four days to slowly cool too which will reduce thermal shock and the result is obviously hot enough for glaze to melt. My Morgan Salamander super clay graphites are made in India in what would be a much larger factory and Peter informs me the 1980's Salamanders were from Japan and came packed in straw or wood shavings just like these ones are. One thing compared to the Chinese sample I bought, there's no lumps of solid fireclay in the mix that can cause crazing of the pottery and as mentioned before they have a glaze on the outside. All in all they look to be reasonably well made and I expect the price would reflect that too and be cheaper than expensive name brand crucibles.
Interesting. I saw this video too. Soooooooo many crucibles ? Is this half of the entire world production and do they also fabricate for Morgan Salamander ?
I both applaud and wince at the use of natural materials for shipping. So many invasive plant and animal species find their way into new locales by such materials. It looks like they have a pretty nice operation and the finished product *looks* good, but what do I know? I'd be curious to hear the opinion on anyone trying some. That's exactly what I thought when I saw them too.
You're not the only one. I suspect it's for the domestic marked, it should be small foundry setups all over the place.
I guess if all the demand is local then using straw for packing isn't a problem until they try to ship overseas. India would be have many small foundry operations and the company in the video probably supplies some of the regional demand for crucibles against other crucible makers. It's hard to know the demand, that may be their annual production of that size for all we know. Morgan has a pretty big operation in India, I did a quick search and found an annual report for Morganite Crucible India Limited part of Morgan Advanced Materials. In amongst all the shareholder blurb is page 5 with all the products they manufacture there including all the crucibles. https://www.morganadvancedmaterials.com/media/7342/morganite-crucible-ar-2018-19-final.pdf Here's the map coordinates of the small street the crucible factory is on somewhere, I see up the Northern end of the street and to the right is a circle that may be a kiln: 16°59'34.57"N 81°48'51.77"E
What I liked was the loose bottom piece for the outside crucible form. Just drops in from the top side, after forming acts as a follower to push the crucible out.
