I have been told that the format of 1L bag of X-Tol was not as tighly sealed - therefore not reliable enough - as it is the case with the 5L one. I don't believe much this explanation; I rather think the 5L is kept alive for industrial use, the regular amateur not being the target, marketing wise...
Think of it like this: people buying the 1l kit are very low volume users, and are the most likely ones to run into problems with expired/inactive Xtol, and will most likely scream about their bad experiences in multiple internet forums. So we are looking at a product (Xtol 1l kit) which creates little revenue and a great risk for the reputation of the product. Any reasonable manager would cancel such a product as quickly as possible.
Think of it like this: people buying the 1l kit are very low volume users, and are the most likely ones to run into problems with expired/inactive Xtol, and will most likely scream about their bad experiences in multiple internet forums. So we are looking at a product (Xtol 1l kit) which creates little revenue and a great risk for the reputation of the product. Any reasonable manager would cancel such a product as quickly as possible.
I mixed up a 5L batch of Xtol on 18th December 2013 from powder that had an expiry date of December 2013 on the packet. The first roll I put through the mix this evening (15th January 2014) is completely clear, no edge markings, zero. It's my fault for not testing the chemistry first on some junk film because I lost some nice shots on that roll.
What are your experiences with the expiry dates on the powder? If the packet is factory sealed shouldn't it be okay? Lesson learnt the hard way.
I mixed up a 5L batch of Xtol on 18th December 2013 from powder that had an expiry date of December 2013 on the packet. The first roll I put through the mix this evening (15th January 2014) is completely clear, no edge markings, zero. .
Wow! So you mix a Kodak developer within its expiry date( usually conservative) and use it about a month later and it gives nothing . No wonder Simon Galley of Ilford believes that his company will be the last man standing in B&W. His competitors are all helping him to realise this ambition as much as they can it would appear
Seriously it would seem to me that your unfortunate experience has to be down to something that isn't intrinsic to Xtol.
Hmmm. To be fair this is only the second time I've ever mixed Xtol but the first time everything worked perfectly. I even got 3+ months from the stock solution without a single problem. I can't see that it was user error. I'll try developing a strip of unexposed film through it to see what happens before I dump the whole lot. I do have some more Xtol powder with a much longer expiry date.
Since no chelating agent completely removes a particular ion from solution, the DTPA in Xtol only slows down the Fenton reaction. Remember that the reaction between a chelating agent and a metal ion like iron (III) is an equilibrium and as such never goes to completion. In addition copper (II) also promotes the reaction. A chelating agent may not have the same effectiveness for all metal ions. Ryuji used two chelating agents, salicylic acid for iron (III) and TEA for copper (II).
I mixed up a 5L batch of Xtol on 18th December 2013 from powder that had an expiry date of December 2013 on the packet. The first roll I put through the mix this evening (15th January 2014) is completely clear, no edge markings, zero. It's my fault for not testing the chemistry first on some junk film because I lost some nice shots on that roll.
What are your experiences with the expiry dates on the powder? If the packet is factory sealed shouldn't it be okay? Lesson learnt the hard way.