Glass was very poor about 100 years ago and it took special glass. But today you can use virtually any glass. I was agreeing with you.
That is a fantastic phrase! Mind if I hold onto it?
Originally Posted by dwross
(ps. I'm back from summer camp! Hurray!)
To clean my glass plates I've been using dishwasher soap, followed by barkeepers friend, followed by a rinse in distilled water. As long as the distilled water sheets evenly I'm happy. The cleaning process reminds me of degreasing a coper plate before putting a soft/hard ground on.
"As long as the distilled water sheets evenly I'm happy. "
That is all that I have been saying all along ! Unfortunately, I sometimes get some glass on which distilled water will bead no matter what I do to clean it. In that case, an overnight soak in undiluted Clorox will will SOMETIMES fix the situation.
Hi, Alex. Nice to see you here again. Welcome back from camp!
Re: 'antique artisan emulsions'
Originally Posted by alexhill
I'm trying to settle into a consistent name that gets across the idea of handmade silver gelatin without having to explain the entire history of photography. You can lose people that way! (Think the average reception where someone asks you, 'So, what kind of photography do you do?' )
I have never coated my own plates therefore if what I suggest is wrong then please ignore my suggestion.
Would a very slight etch with hydrofluoric acid help the emulsion adhere to the glass? I not talking about frosting the glass but an etch so slight as to be invisible to the eye.
A rock pile ceases to be a rock pile the moment a single man contemplates it, bearing within him the image of a cathedral.
~Antoine de Saint-Exupery
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I would suspect so...
but HF is most probably the least practical method, at least for routine use.
Can you describe it's proper handling/storage/disposal?
If you have some and are well positioned to test it - a simple gelatin test coating - with a good number of preferably, particularly difficult plates... could be made.
I have been hesitant to comment,
but I must say I am a bit dissappointed in this thread...
What I mean to say, and I think I am not wrong, is that initally, "perfect" results were claimed... giving credit to a particular cleaning method, which Kirk and Denise endorsed defacto, yet with time, we hear from Wildbillbugman himself... that those methods, rigorous be they are, are in fact not necessarily perfect.
I guess as time goes on we all become wiser....
Last edited by Ray Rogers; 08-28-2010 at 11:03 AM. Click to view previous post history.
Thanks for weighing in. It's not that you have a bad idea. It's that the extra step is unnecessary for almost every emulsion destined to be coated on glass. With an emulsion made with any gelatin but an extra-soft variety, or coated on plates processed at or below 68F, and if reasonable care in cleaning and handling is given, and (very important) with no surfactant except ethanol -- emulsion adherence just isn't an issue.
The oldtimers advised subbing plates with a mixture of chrome alum and methanol and/or adding hardeners to the emulsion and/or the processing chemicals if (and only if) the emulsion was made with very soft gelatin or the plates were going to be handled in summer or tropical weather conditions. For the most part, modern conditions and expectations make things much, much easier. Even if our darkrooms aren't air-conditioned and we're still determined to work in them in the summer, most of us have access to ice cubes.
If anyone decides to rigorously investigate all of the facets of the historical recipes and techniques, the various cleaning, subbing, and hardening protocols will be sussed out, but until then, I would love to see the conceptual barriers to dry plate photography not grow too large in people's imaginations.
I agree with most of what you wrote above as Emulsion can stick pretty well to some glass without any fancy steps at all (evening good cleaning!) but will often show localized weakness.
However, I cannot agree that historical texts in general suggested that special subbing materials were ONLY needed for soft gelatins... Is there a particular text that you had in mind?
Originally Posted by Ray Rogers
You were posting while I was writing. Allow me to comment with a reminder.
Bill doesn't say so every time (nor should he be required to) but he is working with a non-gelatin synthetic colloid of his own design. His emulsions are gelatin-free, so all the rules are different. He readily acknowledges this. I coated some plates that he had cleaned with his protocol, and they worked great. To my mind, though, with a limitation on how much time I have to fuss around, his cleaning protocol is more than is required.
I clean my plates with a paste of calcium carbonate (aka chalk or whiting), Everclear, and 7th Generation Free and Clear dishwashing detergent. After three years as a dry plate photographer, I've made nearly a hundred dry plate negatives -- with maybe a half dozen plates that developed any frilling at all (except when I made the mistake of adding surfactant.) I no longer hesitate to claim authority.
I'm not sure why you won't ever actually make an emulsion, but perhaps you might consider doing so. Experience is always more reliable than 'wisdom'.
Baker, writing in the 19-teens, and Wall both address the issues, as does Clerc (1930's) on tropical conditions. Baker goes so far as to list brand names of gelatins and their hardness numbers. Right now, I still have my copy of Abney out and open from some research I did for Bill. 'Substrata.- With emulsions made with certain kinds of gelatine, the tendency to frill is not easily overcome, in which case it is necessary to coat the plates with a substratum of some sort.' pp114-115. I just sat down to give a quick look at APUG while my gelatin was blooming. Time's up. Your turn!
Originally Posted by Ray Rogers
I have my first assignment for you . Go forth and create a literature review covering all the details of subbing plates. Then, try out all the different gelatins you can find to buy, and develop a test to determine whether or not a particular gelatin/recipe/use condition requires a substratum.
I predict you'll have a lot of fun. It's a lot more satisfying to answer questions than to only ask them.