> Make a 0.2% solution of >Benzotriazole by dissolving 2 grams in a liter of water. >Adding a little Isopropyl alcohol may aid in the solution. In my experience isopropyl alcohol should not be necessary for making a 0.2% solution of benzotriazole. I routinely make a 1% solution without difficulty using warm water. -----Original Message----- From: pure-silver-bounce@xxxxxxxxxxxxx [mailto:pure-silver-bounce@xxxxxxxxxxxxx] On Behalf Of Richard Knoppow Sent: Tuesday, November 08, 2005 12:16 AM To: pure-silver@xxxxxxxxxxxxx Subject: [pure-silver] Re: Five year old paper? ----- Original Message ----- From: "Philippe Gauthier" <pgauth@xxxxxxx> To: <pure-silver@xxxxxxxxxxxxx> Sent: Monday, November 07, 2005 8:22 PM Subject: [pure-silver] Re: Five year old paper? > Richard Knoppow a écrit : > >> As far as buying very old paper I would do it only if >> its _very_ cheap. >> > > I did last year and got relatively lucky. I got a huge > pile of old paper for the equivalent of two US dollars. > Most of the stuff was obviously much too old - for > instance, some 1964 vintage Kodak Panalure, but I was > lucky enough to find a box of 8x10 Ilford MG IV RC and 5x7 > Ilford MG IV RC cooltone in perfect condition. There was > also a package of 10 to 15 years old Seagull Oriental that > turned out to be quite good, but recent looking Kodak > Polycontrast IV turned out to be severely fogged - I could > almost use the test strips as grey cards! > > Now, if I buy some of this paper and find out that there > is some minor fog, how much potassium bromide should I add > to my developer? Can you give me a starting point in grams > per liter? > > PG > For Benzotriazole Make a 0.2% solution of Benzotriazole by dissolving 2 grams in a liter of water. Adding a little Isopropyl alcohol may aid in the solution. Add about 15ml of this solution to a liter of working strength developer and test it. If there is still fog keep adding it in 15 ml increments until the fog disappears. If you add a lot you may have to increase the exposure somewhat. For Potassium bromide I would test with the equivalent of about 5 grams per liter in the _stock_ solution. Dektol and similar developers have around 2 grams per liter as they come. One can increase the amount in the stock to as much as 20 grams per liter although development time will be slowed. I give the equivalent for stock since I don't know how much you dilute. Benzotriazole will tend to shift the paper color toward blue, Bromide toward yellow or brown. --- Richard Knoppow Los Angeles, CA, USA dickburk@xxxxxxxxxxxxx ============================================================================================================= To unsubscribe from this list, go to www.freelists.org and logon to your account (the same e-mail address and password you set-up when you subscribed,) and unsubscribe from there. ============================================================================================================To unsubscribe from this list, go to www.freelists.org and logon to your account (the same e-mail address and password you set-up when you subscribed,) and unsubscribe from there.