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Thread: centrifugal casting??

  1. #1
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    Lightbulb centrifugal casting??

    I've looked up centrifugal casting and watched some video's on youtube etc. even though I'm pretty new on the jewellery scene I think if I had a centrifugal casting machine I could do a lost wax casting with a few sprues at a time in the form of a tree so i.e make a few rings at a time, but a centrifugal casting machine is expensive!!! I would like answers to these questions or advice on these questions aswell thanks.

    1.can I make my own centrifugal casting system for less than buying one and if so what do i need to do so?

    2. can I use dentist centrifugal casting system for jewellery or is that a no no?

    3. does anyone have a spare centrifugal casting system that I can buy at ''mates rates''

    4. thanks for reading the above

  2. #2
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    You can certainly make you own centrifugal machine, but the result could be quite dangerous, if it comes loose or is not balanced. Molten metal is involved and can spray the whole area.

    You can certainly use a dental centrifugal machine as they are one and the same, although for dentistry they have been mostly superseded by vacuum casting. If you Google them, or look for magazines read by dental technicians you should find some.

    You will also need to have a vacuum system for taking the bubbles out of your investment to minimise finishing.That said, for years the investment was merely vibrated on a dental vibrator to get rid of air bubbles. Before that, the casting ring was sat on the notched wooden hub of a polishing brush, on a lathe. Dennis

  3. #3
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    good man dennis! I saw the vacuum part in a video where it vibrates the investment and all the air comes out, also if I did buy a dentist centrifugal system, is that smaller than a jewellery centrifugal system or are they both the same?? I realise I'm punching in the dark somewhat?!?!? also if I purchased jewellery crucibles then would they fit the dentist centrifugal system?? also thanks for the tip on the dentist vibrator if all the answers are yes then coulden't I just build a base around my centrifugal system that's a bigger diameter/circumference, all of these combined would save a lot of £££

  4. #4
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    Something to maybe consider is that if you buy a regular jewellery set up it will be easier to trouble shoot and get to the bottom of problems as other people will have used the same set up. There are many variables to casting and the simpler you can make things to more reliable your results will be.If you do go down the self made route make sure you fit a shield around the machine (an old cut down oil drum or steel dustbin) cause as Dennis said flying molten metal is not ideal !

  5. #5
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    There is of course severe limitation on how much metal you can shift with the power of a spring. I also forgot to mention that the wax will need to be burnt out, and the investment preheated in a furnace. I am glad that Joseph has also underlined the safety aspect.

    You might like to browse Walsh for information here: http://www.hswalsh.com/.

    Their clonky website is not recognising the term casting machine today, so here are some reference numbers to feed into their search box: TC0871, Tc0872, TC083 and for a book on the subject TB17070.

    If you are beginning to find all this rather daunting, consider the Delft clay system TC100. A starter kit will cast flattish, not too detailed items for under £80. Or use cuttle fish from a pet shop. Dennis

  6. #6
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    Hey Dennis, i've used cuttlefish casting to create pieces before and still use this method now, obviously making my own centrifugal casting would need a shield, I am just considering buying a dental centrifugal system though but... (1.) is the spring the same and as strong as a jewellery centrifugal or does it have to be adapted??? (2.) Can it hold the weight of the right size crucibles for silver gold platinum etc?? (3.) can it hold the crucibles themselves? or does it have to be adapted?? (4.) also to your previous post do you just burn the wax out of the investment with a blowtorch and literally melt the wax out of the investment once it has set?? the video's i've seen give information that I woulden't otherwise know, i.e 40ml of purified water to every 100ml of investment powder, and also another question I had was (5.) how do I judge the weight of metal i.e silver to the exact amount of the mould??? if I undercompensate the mould would be ruined? back to square one? if I over compensate, mould will be fine but excess sprays me and my workshop?? advice would be great from anyone thanks

  7. #7
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    one more thing, if I use intricate wax castings, I know I can use these for delft casting also but can I use intricate designs for delft casting or just simple designs??? all the videos I've seen are for simple rings etc.

  8. #8
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    http://www.amazon.com/Centrifugal-Lo.../dp/B000MOLMGK this book is very good and will answer most of you questions I tried to search to see if cooksons stocked it but the website is playing up and I keep getting 404.


    1. depends on the machine dental units tend to be smaller

    2.see 1. you will struggle casting platinum without the correct equipment

    3. see 1.

    4. you need to let the investment set for a couple of hours then burn it out in a controlled manner in a kiln there are set cycles for this depending on the investment powder you use but a 12 hour cycle is pretty reliable in this cycle the kiln will heat to approx 200 C in 2 hours to burn out the wax then it will raise the temp of the kiln to a very high temperature to 'bake' the investment and hold for a preset time then it slowly cools to the temperature to the casting temp of the investment and holds it for a couple of hours so its a uniform temperature,Then you can cast it while its still hot to stop the metal solidifying to soon

    5.you weigh the wax and sprues then multiply the specific gravity of the material your using to get the weight of metal needed
    Last edited by josef1; 20-05-2014 at 11:50 PM.

  9. #9
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    josef1 you are a genius as far as I'm concerned this is brilliant information that will become more than valuable to me in future, but for now I'm teaching myself delft casting, which looks pretty cool and no risk and cheaper than centrifugal but more reliable than cuttlefish also better for one off pieces whereas centrifugal is better for multiples as far as I can see, so thank you all for your help!!! Much appreiciated!!!!!!!!!!

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