> I'll be doing a toner-transfer from a photocopier. Does it need to be
> a laser copier or will a regular copier do?
Any printer or copier using toner as color will work.
some better and some worse.
> I don't plan on using ferric chloride. That leaves, as I understand
> it, sodium persulphate and ammonium persulphate. Are both these going
> to work OK with the Sharpie I plan to use for touch-up? I read in the
> archives of muriatic acid being used, which frankly is not somewhere
> I plan to go, but if I ever do, does toner transfer work with it?
I do not use the "sharpie" because it is not sold here.
i use Steadtler red ink ohp pens. the red is best af all staedtler colors
for resist. i use it in HCl (Muratic acid) & H2H2 and it works.
You can use colophony resin (which is a flux) solved in paint thinner
or denatured alcohol for touch-up also. it withstands HCl and is a flux.
however if you then remove the toner transfer you will srub off the
colophony
and the flux property is of no use.
the toner transfer also works with HCl very good.
i had some "etching through" with hand ironing, where areas of
big pads got a bit dull sometimes, but with the fuser now this
has stopped completely. the plastic of the toner is not attacked
by any etchant i think, only solvents are dangerous for it.
I think you misunderstood the H2O2 thing slightly,
it does not work alone as a etchant.
you need either sulphuric acid or muratic acid with it.
You first make a e.g. 10% muriatic (HCl) acid and put the board
in, then you add a few H2O2 until the etching starts (the board gets dull
red).
you can reuse this etchant ever and ever again. you need only to add h2o2
o keep
it working and if after some time all the HCl is consumed you need
addition of HCl.
you also may need water to adjust. there is this very good document
somewhere
describing the chemistry and adjustment.
I never used any of the persulphates, only FeCl and now the HCl H2O2.
the FeCl is a real mess, i never want to see it again.
It is hard to tell which etchant is best suited, this depends
not only on the intended useage but also on the person using it.
simply use what you like best.
I can not tell you adresses where to get the persulphates, but
the smallest quantities are available at electronic stores (which sell
components and stuff), maybe mail order.
good luck,
and feel free to ask if you have further questions..
ST