[alt-photo] Re: Gum Bichomate used as a resist for metal printing

[Jack Brubaker]

Keith,

Several thoughts. There are a lot of materials that will color metals. There
is a great company in WS that makes patina solutions that I use. They are at
www.epi.com. I also use JAX Chemical Company patinas. In the past EPI would
send out one pint samples for free. Don't know if that is true today.

I use the EPI patinas in a spray bottle and mist them on either just enough
to speckle the surface or to flood it.

I prepare the metal by sandblasting most of the time, but scrubbing it clean
with a Scotch-Brite pad will work. If the patina beads up on part of the
piece scrub the patina in with a scotch-brite pad. The acid content in the
solution usually helps clean the surface.

On steel I use their Insta Blak 333 on steel and copper based metals. I
don't know if I have tried it on aluminum. I buy that stuff in 5 gallon
pails. If you want to try some let me know and I'll send you a sample. If I
remember they don't actually sell smaller quantities than 5 gals.

Sand blasting is another idea. I have wondered about blasting a metal plate
with a thick gum image on it. The gum might hold up long enough to form an
image. Perhaps sand blast first and blacken with the patina then do the gum
image (the blasted surface should hold the gum well) and blast off the
exposed blackening to make the final image. The gum might break down slowly
enough to form a tonal image. I've been meaning to try this for 20 years.
Next time you come this way let's play with it!

Jack Brubaker

On Sat, Feb 5, 2011 at 12:02 PM, Keith Gerling <keith.gerling at gmail.com>wrote:

> As i recall, the artist used gum for a resist, then immersed steel plates
> in
> various corrosive agents to get different colors.  What I am looking for is
> what those agents are.
>
> Any ideas, Jack?  You're the metal expert!  What would be even better is if
> you had any thoughts on how i could tarnish/blemish/colorize aluminum.  I
> have loads of aluminum that I could use for this.
>
> As for removing it, if it doesnt dissolve in one of the solutions, I can
> always hit it with a blowtorch.
>
>
>
>
> it just dawned on my that you're going to polymerise the gum with
> bichromate
> which is of course going to make it insoluble in water. Your possibilities
> for using an etch then broaden (I'd try high strength hydrogen peroxide
> maybe). How do you remove the hardened gum after the etch though? ~m
>
> >
> >
> > On 2/5/2011 6:12 AM, Keith Gerling wrote:
> >
> >> Some years ago I remember seeing some links to some metal work.  I
> believe
> >> the artist used gum to create a resist and then allowed corrosion to
> >> create
> >> the image on steel.  Does anyone have these links bookmarked?
> >> _______________________________________________
> >> Alt-photo-process-list | http://altphotolist.org/listinfo
> >>
> >>  _______________________________________________
> > Alt-photo-process-list | http://altphotolist.org/listinfo
> >
> _______________________________________________
> Alt-photo-process-list | http://altphotolist.org/listinfo
>