>I have never understood the hooha about no metal, since I have never yet
>heard of a platinum printer immersing a brush in platinum emulsion up to
>the ferrule, unless the mere proximity of metal to the emulsion has a
>voodoo effect -- which is certainly possible. You get the bottom third of
>the hairs wet, if that. In my experience, those who use a brush (in
>preference to patented "puddle pusher" in US, glass rod,elsewhere),
>generally cut half the bristles off across the width, then reinforce base
>of hairs with hard-drying glue (what we call "airplane glue") squeezed
>along base, worked into hairs.
If platinum solutions soak through the hairs to the ' iron' ferule the
sensitiser becomes contaminated with iron and prints become muddy and grey. With
gum the dichromate speeds up the rusting of the ferule so you get bits in your
picture.
If you use brushes with no metal in the ferule you do not have this trouble so
there is no need for messy methods of dealing with avoidable problems.
Hair spray Judy ! Forsooth and egad !
Incidentally the glass rod method has been recommended for well over one
hundred years. For larger pictures brushes are more effective and there is no
greater loss of solution than one suffers with a glass rod.
Terry King