RE: Mike Ware's POP Pt./Pd. Pt
Hi Witho. Maybe the problem you mention is related to bad clearing / washing (=remaining sensitizer / clearing agent in the paper) - but I don't think the phenomenon is *exactly* caused by the mechanism you describe. My understanding of chelating agent is something that makes a soluble compound with another compound that is not soluble itself. Since there will be no water in the paper (except the humidity absorbed from the environment - a minute amnt. when compared to wet paper), I don't see any reason for the remaining chelating agent making loose the metal *trapped* inside the paper's fibers, causing them fall(?) - if I'm getting you correctly. 1) How will the chelating agent contact with the metal particles in a dry environment? 2) And how will it break the physical bonds between the metal particles and the paper's fibers? Of course I acknowledge that the remaining chemicals may form new compounds with the image-making metal particles; rendering them transparent/colorless, therefore useless for image-making purposes... But since we're talking about intert noble metals, I don't see how that could happen!? Quite confusing isn't it? Since you're observing image loss, for sure something is happening - but what? Anyway, your "wash good" suggestion is a very sound one - anyone dealing with precious metals for doing images should care to follow a good procedure; it won't make sense to be casual with these processes / doing so would take much from their value and from their purpose. Best regards, Loris. ----- Message from info@witho.nl --------- Date: Thu, 09 Nov 2006 16:50:11 +0100 From: Witho Worms <info@witho.nl> Reply-To: alt-photo-process-l@usask.ca Subject: RE: Mike Ware's POP Pt./Pd. Pt To: alt-photo-process-l@usask.ca Sandy, I have no hard (or scientific evidence) but I have seen that fragment of proofs of my prints or misprints, which I kept over years, start to show defects and damage. So I related these problems to bad clearing. EDTA is a chelating agent. I have read that it more or less encapsulates metal molecules and makes them better soluble in water. Even people are treated with it intravenously to wash out metals from their body. (EDTA might probably the only chemical in alt-photography which benefits to our health). So, my reasoning is simple. Over time encapsulated metal particles may come loose from the paper fibres. I do recall that Tyranno King mentioned something about EDTA to some months ago. Regards, Witho _____ Van: Sandy King [mailto:sanking@clemson.edu] Verzonden: donderdag 9 november 2006 16:15 Aan: alt-photo-process-l@usask.ca Onderwerp: RE: Mike Ware's POP Pt./Pd. Pt Witho, Any idea as to the cause of this? Sandy At 9:22 AM +0100 11/9/06, Witho Worms wrote: Hallo Sandy, Be sure to do a very good final wash when using EDTA for clearing. If the wash is not complete you will face that palladium will come off the paper during time (one or two years). Regards, Witho -----Oorspronkelijk bericht----- Van: Sandy King [mailto:sanking@clemson.edu] Verzonden: donderdag 9 november 2006 7:41 Aan: alt-photo-process-l@usask.ca Onderwerp: RE: Mike Ware's POP Pt./Pd. Pt Hi Loris, Will get the lithium chloride. Your advice has been outstanding so far, and I am very pleased with the results. Just wondering, have you done any work with AFO and kallitype? The clearing of prints in Disodium EDTA made with FAO and Ammonium Tetrachloropalladate (II) is so quick and easy I am wondering if the procedure can be adapted to silver nitrate. Best, Sandy At 8:15 AM +0200 11/9/06, Loris Medici wrote:Good news Sandy. I'm glad that you like the alternative sensitizer. Do yourself a favor and also purchase some (cheap, B&S has it) Lithium Chloride - to make some Li2PdCl4. (Don't skip this - it's quite a good hint IMO.) My pleasure. Best regards, Loris. -----Original Message----- From: Sandy King [mailto:sanking@clemson.edu] Sent: 09 KasÏm 2006 Pers¸embe 03:22 To: alt-photo-process-l@usask.ca Subject: Mike Ware's POP Pt./Pd. Pt I finally received some ferric ammonium oxalate today and was able to do a few tests with Mike Ware's POP Pt./Pd. process. The results were very encouraging. The Dmax I was able to get with the sensitizer of FAO + Ammonium Tetrachloropalladate (II), on the first try, was definitely better than I have been able to get with palladium printing using FO in my working conditions. I am working in a room with about 60% RH, which gives a sepia color print with straight palladium. I am also exposing by time, not visual inspection. I would also add that working with the FAO is a real delight compared to FO. It mixes up quickly and completely in about 5-10 minutes, and results are very low fog. I am using Mike Ware's recommended post-exposure processing, which you can find oin his web site (http://www.mikeware.co.uk/mikeware/Platino-Palladiotype.html), but I have also found that I can get contrast control with the Disodium EDTA with dichroamte. Mike does not specifically recommend this approach, as I recall, but I find that it gives a lot of flexibility to the process.. In any event, I thank Loris Medici for putting me on the potential advantages of FAO. Lots of potential here I believe. Sandy King ----- End message from info@witho.nl -----
|