RE: Black spots in Pt./Pd.

From: Sandy King ^lt;sanking@clemson.edu>
Date: 08/09/05-02:31:08 PM Z
Message-id: <a0602040dbf1ec2a3c8dd@[192.168.2.2]>

I began with a clean foam brush so that does not appear to be the
problem, except for the fact that the Lenox paper is soft that it is
suffers abrasions easily when you coat.

Sandy

>How about contamination in the foam brush rather than an abrasion issue?
>Where did your foam brushes come from? I also find that a 2" foam brush is
>more likely to give a better coating than a 1 " even when coating down to
>5x7 or 4x5.
>
>Eric Neilsen Photography
>4101 Commerce Street, Suite 9
>Dallas, TX 75226
>214-827-8301
>http://ericneilsenphotography.com
>
>> -----Original Message-----
>> From: Sandy King [mailto:sanking@clemson.edu]
>> Sent: Tuesday, August 09, 2005 12:17 PM
>> To: alt-photo-process-l@sask.usask.ca
>> Subject: RE: Black spots in Pt./Pd.
>>
>> Bob,
>>
>> Thanks for the informative reply.
>>
>> I have now figured out that the problem was indeed the Lenox paper,
>> but it was not caused by the paper itself, or by the chemistry, but
>> by the way i coated the paper. The thing is, I was doing some 4X5
>> tests and the small 1" Richeson that I normally use for this is not
>> to be found, so I used instead a small 1" foam brush. Well, the
>> surface of the Lexox paper abrades *very* easily and it turns out
>> that the abrasion is the cause of the spots. The other papers that I
>> use have a harder surface and the foam brush did not cause the same
>> problem.
>>
>> Have another small Richeon on the way so will wait to do any more
>> tests on Lenox until it arrives.
>>
>> Sandy
>>
>>
>>
>>
>>
>> >DEAR SANDY,
>> > My 3 cents...
>> > I have never found any problem with Lennox so I feel that is a low
>> >probability. What I DID find is that I have to clean the necks of my
>> Ferric
>> >Oxalate dropper bottles and the inside of the dropper cap EVERY TIME
>> before
>> >use. The crust of desiccated FO on them can fall into the solution as
>> fine
>> >clumps or crystals and create black spots upon development. I had black
>> >spots on my prints using Lennox, Cranes Platinotype, and COT before I
>> >started doing this and I have never had any spots since!
>> > If you don't use droppers look for some place where the FO can dry
>> and
>> >crystallize as the source of trouble.
>> > Some suggest that, if your metal solutions aren't warm enough
>> >you can get
>> >precipitates that can cause similar problems but, living in the tropics,
>> I
>> >don't have that problem Some suggest that roller paper trimmers emit
>> shards
>> >of iron or steel that can cause the same spots but I use a roller trimmer
>> >and have never had a problem with any of the papers above.
>> >
>> > Please check my website: http://www.bobkiss.com/
>> >
>> >-----Original Message-----
>> >From: Sandy King [mailto:sanking@clemson.edu]
>> >Sent: Tuesday, August 09, 2005 11:57 AM
>> >To: alt-photo-process-l@sask.usask.ca
>> >Subject: Black spots in Pt./Pd.
>> >
>> >
>> >Another Pt./Pd.question.
>> >
>> >I have not done any Pt./Pd.printing in about 6-8 months and when I
>> >began trying to calibrate my materials again I ran into a problem
>> >that I have not seen before, small black spots on the print that
>> >appear during development.
>> >
>> >The chemistry that I am using 1 part of 25% ferric oxalate plus 1
>> >part of 20% palladium chloride. The solutions are clear and are
>> >giving very good Dmax, even though they were mixed several months ago.
>> >
>> >The paper is Lenox, which I have not previously used for Pt./Pd. printing
>> >
>> >Does this sound like a paper issue, chemistry issue, or some type of
>> >contamination I am not understanding.
>> >
>> >Sandy
Received on Tue Aug 9 14:31:26 2005

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