Homebrew PCBs

At Tue, 28 Mar 2006 12:10, Stefan Trethan wrote:
>On Tue, 28 Mar 2006 11:35:17 +0200, roger lucas wrote:
>
> > Zoran,
> > Are we talking bog standard white candles here or are
> > there special candles we need to obtain for this to
> > work.
> > Roger
>
>I think most candles are made of paraffin these days,
>get the cheapest and don't get "oil" ones and you should be fine.
>It should smell like burning PE, or rather burning PE smells like paraffin
>
>ST

Most candles are based on paraffin wax. Better quality candles
contain a hardener, such as stearic acid, or beeswax, which
makes them smell nice too. Good for burning time but probably
largely irrelevant to this application.

You can buy "Paraffin Wax BP" in slabs to order in UK chemists
shops (pharmacies). Granulated paraffin wax and stearic acid
powder are available from candlemaking suppliers - you might try
a local art & craft shop. The advantage of granulation is easier
handling and measuring and quicker melting, again of little
consequence to us.

Probably the cheapest and by far the most widely available source
is the "tea light"  - they are used for food warmers, night lights and
aromatherapy burners, so you find bags of them in street markets
and discount stores everywhere. They even have a convenient little
metal pot in which to melt the wax and store the remainder :-)

Whatever you use,it would be best to stick to the same
source to avoid inconsistencies in plotting through variations
in melting point - but one bag of tea lights, or one altar candle
will make a _lot_ of PCBs :-)

BTW, in reply to an earlier post in this thread, a technical pen
has a tubular nib with a fine wire attached to a weight. The wire
is purely as a mechanical nib cleaner, since drawing inks are
usually pigment based (traditional India or China ink is basically
lamp black in suspension in dilute gum arabic). Since the nib
is a metal & plastic assembly, it would be difficult to ensure
enough heat flow to keep the wax from solidifying in the nib
while avoiding melting the plastic.


Regards, LenW
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