Alfa-Aeser have chlorhydroquinone, but will sell in the USA only to companies. I arranged to buy some from them but their transport cost to me in Australia was very high. I'm used to paying through the nose occasionally, but this was bizarre.
John ========================== Don Sweet wrote:
A few weeks ago there was a discussion on this list about the possible use of chlorhydroquinone as an anti-fogging developer for old paper, if only you could find some. Since then I have found there is a recipe for "Maxim Muir's Chlorhydroquinone-Substitute Developer" on page 174 of Carson Graves' book The Elements of Black and White Printing (2ed), which provides a work-around for the chlorhydroquinone shortage if anyone is interested. Don Sweet----- Original Message ----- From: "Richard Knoppow" <dickburk@xxxxxxxxxxxxx>To: <pure-silver@xxxxxxxxxxxxx> Sent: Wednesday, April 09, 2008 2:19 PM Subject: [pure-silver] Re: Potassium Bromide----- Original Message ----- From: "Dennis Purdy" <dlp4777@xxxxxxxxxxxxx>To: <pure-silver@xxxxxxxxxxxxx> Sent: Tuesday, April 08, 2008 5:35 PM Subject: [pure-silver] Re: Potassium Bromide I have some that is the same as yours. Old and chunky or solid and I just chop it up and use it and it works fine. Though I am not sure it will do you much good saving old fogged paper. I think you need anti fog #1 or (benzotriazole). Dennis On Apr 8, 2008, at 16:36, mmagid3005@xxxxxxx wrote: I don't know for certain about the Kbr but think it has just absorbed some moisture. Kbr is not as effective an anti-foggant as benzotriazole but is worth trying since you have it. Quite a lot can be added to the developer but beyond perhaps 5 grams/liter it will begin to cause a speed loss. Ira Currant, who was Ansco's expert on toning, has a patent for developers for cold sepia toning which contain huge amounts of bromide. While bromide is usually recommended for getting warm tones on paper and warmer toned images Currant discovered that in very large amounts it resulted in colder sepia tones. The developer examples shown in the patent were similar to standard Ansco print developers, one substantially the same as Dektol. He used bromide up to 50 grams per liter. The relevance here is that large amounts of bromide are OK but exposure will have to be increased. I suggest cutting a sheet into test strips and seeing how much fog is produced with varying amounts of bromide. Fix out a bit without any exposure or development to get a comparison. In general benzotriazole has greater anti-fog effect with less speed loss. The latent image centers from chemical fogging and from light are somewhat different so its possible to suppress the fog without destroying the low level latent image, at least not completely. Let us know your results. --- Richard Knoppow Los Angeles, CA, USA dickburk@xxxxxxxxxxxxx============================================================================ =================================To unsubscribe from this list, go to www.freelists.org and logon to youraccount (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.
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