Archive of the former Yahoo!Groups mailing list: Homebrew PCBs

----- Original Message -----
From: "Thomas P. Gootee" <tomg@...>
To: <Homebrew_PCBs@yahoogroups.com>
Sent: Sunday, September 12, 2004 9:58 PM
Subject: [Homebrew_PCBs] Re: Dextrin as release from TT paper


> Two slightly-related observations, since this thread's aim seems to be
> about achieving better/easier release of the paper from the board and
> toner, after the toner transfer: (PLEASE, also: Read the section farther
> below, about a special request for everyone's help/participation, which
> requires a quick test of as many different printers and copiers as
> possible. i.e. yours too.)
>
> 1.) I posted a question, a while back, in a sci.chemistry Usenet
> newsgroup (http://groups.google.com), asking specifically if anyone there
> could suggest any sort of substances or procedures that would tend to
> dissolve paper but not dissolve toner (nor copper). I think that there
> was only one suggestion that I hadn't already tried that also seemed worth
> investigating. And that was: Sodium Hydroxide, a.k.a. "Lye", a.k.a. NaOH.
> I haven't been able to find the time (or the lye) to try it, yet, though.
> If anyone HAS tried it, or can try it sooner than I can, I would
> appreciate hearing about it. (Suggestions for common sources of lye would
> be appreciated, also.)

In the UK, NaOH is available from some ironmongers and builders merchants,
for clearing drains and sinks. I use it as a resist developer. I just made
up a small quantity of a saturated solution and put a small piece of paper
in it. It doesn't seem to have done anything to it, although the solution
was quite hot due to the heat produced when the NaOH was mixed with the
water.

I've just tried a Google search for a solvent for cellulose, which is what
paper basically consists of, and they are generally rather complex
compounds. Schweizer's reagent (a cuprammonium hydroxide solution) was the
first and probably simplest, I think it was used for making rayon. Sodium
hydroxide mixed with carbon disulphide (CS2) is used commercially for
dissolving cellulose, presumably in a pressure vessel. I remember using CS2
at school many years ago, it's very nasty stuff.

Leon