Hi Donald,
You wrote, I think of the glue I am using:
> I'm quite sure it is gum arabic
> http://en.wikipedia.org/wiki/Gum_arabic, which is a very common paper
> adhesive where toxicity might be an issue (stamps, envelopes, ...)
> Readily dissolves in water; stable; long-lived.
This liquid has no colour. When dried it turns into a firm, clear,
plastic-material which is uncoloured (except for browning in the oven at
200C). That material can be softened and probably dissolved in water.
The MSDS indicates it is 10 to 15% Poly Vinyl Alcohol - and I can't
think of any reason to dispute this. My initial tests indicate it is
good for laser transfer paper.
- Robin
http://www.firstpr.com.au/pcb-diy/