Re: Wash off

[William Marsh <redcloud54@earthlink.net>]

Jeffrey,

Last night I allowed the coating to sit for 15 minutes before drying. 
This seemed to help alot.  Clearing took much longer, however, requiring
the use of both EDTA and PermaWash in series for 20 minutes to clear.

Not using any EDTA in the coating mixture.  The ferric oxalate is
straight FO and distilled water - 7.5 gm in 25 ml.  I tried using EDTA
and oxalic acid in the ferric oxalate sensitizer some time ago, and got
very weak results.

I have no idea what the metal solution strengths are.  They are the
standards manufactured by Dick Sullivan, slightly warmed.

Filtering the developer several times has removed much of the gray
color, so I'm going to keep using it for awhile.  It doesn't *seem* to
stain the paper, the whites in the print seem close to paper white when
compared to unprocessed paper.

Does Bienfang still do that seersucker thing?

Thanks so much for your help. I really appreciate it.

Bill

"Jeffrey D. Mathias" wrote:
> 
> William Marsh wrote:
> > ...
> > 4 - 5 min. exposure gives a deep black in the edge, but enough coating
> > is coming off to turn a pint of developer noticeably greyish just doing
> > 3 test strips and one print.  Even though the edges are black, it stands
> > to reason that emulsion must be coming off the image areas as well,
> > weakening them.
> 
> Technically the coating is not an emulsion.  Several things might cause
> this "bleeding" you have noticed.
> 
> +  As Kerik has mentioned, this paper may need to have the coating
> mixture soak in better.  Several papers require this, but others may
> not.  However, do not let the fresh coating sit around for more than an
> hour before exposure as this will likely degrade the print quality.  Try
> a paper like Bienfang 360 and see if the "bleeding" still occurs.
> 
> +  Are you using EDTA in the coating mixture?  Too much can cause
> "bleeding".  Try lowering the amount of EDTA if present.  Is EDTA added
> to the sensitizer?  Try a different batch or source of sensitizer.
> 
> +  What are your metal salt solution strengths.  Too high a solution
> strength will contain excess metal which becomes wasted and washed off
> during processing.  There is a lot of information on the solution
> strengths in my guide (available at link below).  Check out the studies
> for optimization and verification of process equations and formulas.
> Many of the formulas and books out there don't put in enough metal, but
> some put in too much.  Not enough will result in a weak print, too much
> will be wasted.
> 
> Some metal in the developer should not hurt it; some even claim it to be
> beneficial.  However, used sensitizer solution can eventually build up
> and result in a fogging of prints.  Usually enough of the developer is
> carried away that replenishment of fresh keeps this sensitizer level
> down, but really old developers may have this problem.
> 
> --
> Jeffrey D. Mathias
> http://home.att.net/~jeffrey.d.mathias/