[alt-photo] Re: Question for Platinum/Palladium printers

[etienne garbaux]

Denny wrote:

>I'm using 3% citric acid for 5 minutes followed by HCA with Stonehenge and
>it seems to be working.  I mask the negs for white borders and the borders
>look clear.  Is there a more definitive test for residual iron that should
>be used?

Definitely, if you want some assurance that your prints are archival 
-- visible clearing tells you nothing about that.  There are a number 
of old tests that work, but a modern method used by conservators is 
discussed here:

http://www.apug.org/forums/forum42/89406-residual-iron-test.html

http://www.irongallink.org/images/file/pdf%201%20_iron_ii_test__ok.pdf

http://www.irongallink.org/images/file/pdf%202_preparation%20of%20ascorbic%20acid_ok.pdf

http://www.irongallink.org/images/file/pdf%203_fe%20test%20artikel.pdf

http://www.irongallink.org/images/file/icom14_161.pdf


Also, Dequest (http://www.dequest.com/) reportedly makes some iron 
sequestering agents that are strong enough to solubilize insoluble 
iron complexes.  Some of these may be suitable for clearing 
iron-based prints, assuming that they have no deleterious side 
effects, but I am not aware of any testing having been done for this 
application.

Best regards,

etienne