making you own knobs

[Dave Wilke]

The problem with centrifugal casting with resins is the setting time.  
Molten gold in a lost-wax casting solidifies in perhaps 5 to 10 seconds.  
The centrifuge spins for this entire time.  A good casting resin will take 
perhaps 5 to 10 minutes... a long time to spin a can!

Professional casting centrifuges are available, but a small vacuum chamber 
would be less expensive (still several hundred dollars, though).

dave


>From: Paul Perry <pfperry at melbpc.org.au>
>To: synth-diy at node12b53.a2000.nl
>Subject: Re: making you own knobs
>Date: Wed, 18 Oct 2000 18:30:14 +1000
>
>At 09:46 AM 16/10/00 +0200, jorgen.bergfors wrote:
>
> >The only problem with this method is avoiding air bubbles. If you have
>access to a vacuum chamber, you are lucky. I don't, so I have to be careful
>to avoid bubbles.
>
>The way jewellers avoid air bubbles with small work like this, is
>to put the whole mould in a can on a rope and swing it around!
>letting centrigugal force do the work. Now if they can do this with
>molten metal alloys (typically zinc) we should be able to do it
>with epoxy, no sweat!
>
>paul perry Mlebourne australia (glad to be back! I love AHOT, but...)
>

_________________________________________________________________________
Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com.

Share information about yourself, create your own public profile at 
http://profiles.msn.com.