Magpie
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metalsmith
Metalresearcher, I was wondering if you do any metal casting using the lost wax process. Specifically, I'm wanting to learn how to cast a silver or
brass retort (RBF), about 100mL capacity, 2-3mm wall thickness.
The single most important condition for a successful synthesis is good mixing - Nicodem
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Mr. Wizard
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A silver flask would be an ideal electro forming project plated onto a low melting alloy or a form coated with graphite, aluminum foil, or spray
galvanizing paint.
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BromicAcid
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At one time I was looking into the lost wax process specifically for making a silver retort (for hydrazine) however I found that without a significant
investment of time (and to some extent equipment) I wouldn't have been able to get good enough to perform the feat I so wanted so I looked into
electroforming. Check out this thread:
http://www.sciencemadness.org/talk/viewthread.php?tid=1990
I don't see any comments from you in it so it may be new for you. Sadly enough even after learning about electroforming it didn't seem that much
easier. Developing an even coating can be difficult as can electroforming a coating thick enough to work with. Best of luck with this one 
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Magpie
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Quote: Originally posted by BromicAcid  | | At one time I was looking into the lost wax process specifically for making a silver retort (for hydrazine) however I found that without a significant
investment of time (and to some extent equipment) I wouldn't have been able to get good enough to perform the feat... |
This is the same purpose and conclusions I have.  Between Vogel and OrgSyn,
silver or copper can be used.
When I read the hydrazine procedure I did not see why I couldn't use glass so I gave it a try with a 100mL RBF. The problem is not corrosion but
terrible heat transfer that is caused by solids that settle on the bottom of the retort. I terminated the distillation early as I was afraid I would
crack the RBF. Consequently my hydrazine was only 3% vs the design value of ~25%.
I only recently wanted to make the hydrazine so don't even recall the thread you indicated. Maybe it was before my time. Reading though it further
confirms my prejudices about electroplating/electroforming. I just have no experience in that area.
The single most important condition for a successful synthesis is good mixing - Nicodem
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metalresearcher
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| Quote: Originally posted by Magpie |
Metalresearcher, I was wondering if you do any metal casting using the lost wax process. Specifically, I'm wanting to learn how to cast a silver or
brass retort (RBF), about 100mL capacity, 2-3mm wall thickness. |
I did this years ago I still have the cristobalite investment now I do more sand casting and casting blanks for making wire and sheet. But I'll do
lost wax later on.
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metalresearcher
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Thai I 'll do the lost wax casting in the near future .... I still have the equipment.
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Wizzard
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It'd be easier to vacuum deposit zinc onto whatever you'd want to plate- Zinc is gaseous and will adhere at 900*C in a low vacuum.
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Magpie
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When I looked into this it seems like a centrifugal caster and possibly a vacuum bell jar would be required. I already have a muffle furnace capable
of melting silver, and I have found a brass that I could likely also melt.
Used centrifugal casters for dentistry are available on eBay, but they are a bit expensive. There are many for sale so a person might get lucky and
get one cheap.
What equipment do you use for this process? Do you think casting a 100mL round bottom flask (RBF) would be quite a challenge?
The single most important condition for a successful synthesis is good mixing - Nicodem
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watson.fawkes
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| Quote: Originally posted by Magpie | | What equipment do you use for this process? Do you think casting a 100mL round bottom flask (RBF) would be quite a challenge? |
I might mention that many art foundries will happily take on contract work, if you're more interested in acquisition than making it
yourself. If you can provide them a wax positive, they don't have to charge you for the labor of making one.
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Fleaker
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I do lost wax casting. I have some Kerr-satin cast that I no longer use if you'd like it; just pay shipping. It is still good. I also have some
molding wax, beeswax, paraffin, and some fillers too sitting around somewhere.
I also have silver too :-)
Neither flask nor beaker.
"Kid, you don't even know just what you don't know. "
--The Dark Lord Sauron
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Magpie
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Hello Fleaker. What is your opinion of my proposed casting of a silver or brass 100mL RBF? Do you think it would be tough to do?
Would you prepare a solid sphere negative of investment first, then coat the inside of this with 2-3mm of wax, then pour a solid sphere of investment
inside the wax shell? Or what? Just how would you do this?
The single most important condition for a successful synthesis is good mixing - Nicodem
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quicksilver
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One of the FINEST jewelery makers I ever knew started as a teenager & was a close friend. His whole life was different aspects of jewelery making
and he used lost-wax like no one I had ever seen or have seen accomplish better.
He had a little "H" shaped pivot for his molten metal and used it to "time" the pouring of metal which he insisted was his "secret" to getting such
ultra fine casts. The "H" shaped platform kept his timing of pour to a certain level as also his lack of "giggle" or hesitancy. The item was home-made
and simply consisted of a stand such as a "goal post" which he could insert a ladle of molten metal (he used both silver & gold).
I have NEVER seen such items duplicated as he did. And he was very free with his knowledge. He once said that very fine professional wax had different
"speed grades" of pour with differing metals and that certain suppliers had that information whereas others never even heard of that issue.
He once did a series of bronze castings in the "old style" of bronze age casting in which he made arrow heads, spear heads, a knife, & a sword. He
then found a collection of aging chemicals which put such a deep crust of patina on them that it was honestly difficult to believe they were
manufactured a week ago.
I do know that he once said that he thought about writing a book and I hesitate to write his name in public but if I ever DO find that he wrote one I
will post it as I really believe he was as gifted a man a I had known in that art. I knew him from when we were about 13 to out late 20's & he was
mostly self taught!
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Texium
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Thread Moved
19-11-2023 at 16:04 |
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