RE: Ferric Oxalate or Ferric Ammonium Oxalate
Clay, did you use the ammonium tetrachloropalladate with DOP printing with FAO or FO?. And how did you control contrast? I would really be more interested in using FAO with DOP than POP since visually evaluating density would be hard to do with a vaccum frame. So if the FAO works with ammonium tetrachloropalladate developing in potassium oxalate, and I can use dichromate contrast control in the developer, that would be a perfect solution for me.
At 12:35 PM -0600 11/3/06, firstname.lastname@example.org wrote:
Sandy, Yes, that is all you need to make the Ware formulations. You will notice that his metal salt concentrations are slightly higher than is typically used in DOP. I have used the ammonium tetrachloropalladate for DOP printing as well. I think it has a visually deeper Dmax and a more neutral tone than the sodium salt version. ClayLoris, I have Palladium II Chloride powder on hand. Looking at Mike Ware's directions, it appears that I can prepare Ammonium Tetrachloropalladate(II) by mising ammonium chloride with palladum II chrloride. Would this be all I need, along with the FAO, to give Ware's POP method a try? In other words, can a basic sensitizer be made with just Ammonium Tetrachloropalladate(II) and Ammonium Ferric Oxalate, or do I need something else? Also Is it possible to control contrast with the Ware method with dichromate? I would rather do this than attempt to do so by varying RH? Sandy At 9:01 AM +0200 11/3/06, Loris Medici wrote:Hi Kerik, Main salt: Li2PdCl4. Metal additives (for color control - sometimes): K2PtCl4 and KAuCl4. Non-metal additives: NaOW and Amm.Di. (for contrast and color control). Regards, Loris. P.S. Your "reply-to" address is not empty, so I had to write the group's address manually. -----Original Message----- From: Kerik [mailto:email@example.com] Sent: 03 Kas×m 2006 Cuma 08:24 To: firstname.lastname@example.org Subject: RE: Ferric Oxalate or Ferric Ammonium Oxalate Loris, Which metal salts are you using with AFO? Thanks, Kerik-----Original Message----- From: Loris Medici [mailto:email@example.com] Sent: Thursday, November 02, 2006 10:10 PM To: firstname.lastname@example.org Subject: RE: Ferric Oxalate or Ferric Ammonium Oxalate Hi Eric, I haven't done prints with FO other than few Kallitype tests so I can't share personal experience w/ it as a sensitizer for Pt/Pd salts but I'm quite sure that my prints don't exhibit any haze and/or highlight fogging and/or low contrast. Probably yours is a paper/clearing and/or negative DR problem - my usual coating mix gives me 29 steps in the 31-step tablet for instance (in other words my usual negative DR is log 2.9!). I'm currently using the same AFO sensitizer that I mixed about 10 months ago and it still works well without any fogging and/or speed change or other negative effect. IME AFO is quite stable even when in solution - you can almost think that it keeps indefinitely "especially when compared to FO". Regards, Loris.