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wildbillbugman
08-08-2010, 02:47 PM
Hello to all,
Glass cleaning has been discussed thoroughly on this forum. I have my own procedure that I have published on Denise Ross's Thelighjtfarm.com . Whatever the cleaning procedure one uses, I think that a piece of glass should be able to hold a vertical sheet of water without breaking up or beading. It seams reasonable that a surface that cannot sustain a sheet of water cannot support an aqueous emulsion or solution.
Sometimes I get an entire batch of glass that will not hold a vertical sheet of water no matter what I do. Adding a wash in ethanol has no effect. Even a micro-etch in NAOH
will not help. I conclude that my entire batch of glass is not usable due to something inherent in the glass.
I remember,years ago, running across a publication from KODAK discussing the quality of glass required for dry plates.
I wonder if anyone is familiar with any glass "standards" employed by the old glass plate manufacturers.
Thanks,
Bill
P.S. Coating with only IR light is a great big PAIN. Poor depth perception! I have a hard time finding the middle of the plate!

Photo Engineer
08-08-2010, 03:35 PM
Bill;

I think you will find that many glass plates refuse to allow water to sheet on them. That is what surfactant is for. A small amount will go a long way. And, there are 3 types of surfactant. They are Anionic, Cationic and Non-Ionic. Photo Flo 200 and the Tween family belong to the latter. Triton X 200 anionic.

PE

wildbillbugman
08-08-2010, 05:12 PM
PE,
I take your point. All my Emulsions contain ethyl alcohol and most contain some Triton X200. But the vast majority of of glass I use dose sustain a standing sheet of distilled water until the water evaporates..
I have noticed that most antique boxes of glass plates contain glass that is low in green color, compared to today's standard plate glass. This indicates lower Iron content.
I do find it interesting that any sheet of glass which will hold a vertical sheet of distilled water NEVER,EVER frills upon processing.
Bill

dwross
08-18-2010, 01:00 PM
Bill,

There are two sources of easy-to-access info that I know about.

1) Photography with Emulsions, by W. Abney, 1885, starting on page 114. It's available as a Google book from the TLF lit list, #5: http://thelightfarm.com/Map/LiteratureList/LiteratureListPart1.htm

2) Wall's 1929 Photographic Emulsions. p.162.

And, though I feel like a broken record, I don't support the use of a surfactant in emulsions coated on glass. The times I tried were the only times my coating failed miserably. You're not using gelatin, so of course your situation might be different, but a reminder anyway.

wildbillbugman
08-18-2010, 04:43 PM
Thank You Denise,
I was particularly gratified that W. Abney specifically confirmsthe importance of a standing sheet of water as a test for cleanliness of glass plates. I have sulfuric acid (Wall) and will get some Nitric acid (Abney). But really, the acid/base cleaning method is very similar to the way in which I already clean glass. But I use oxalic acid and phosphoric acid, at different times.
Bill

wildbillbugman
08-19-2010, 12:44 PM
W.Abney also points out that many emulsions have been dismissed and discarded because they failed to adhere to dirty glass.
Bill

Kirk Keyes
08-20-2010, 12:13 AM
Bill - If you're going to be using sulfuric, look for a lab supply place and get some stuff called "NoChromix" - http://godax.com/

You add a packet of the stuff to conc. sulfuric acid and then you just soak the glass in the Nochromix/sulfuric solution. It will clean most everything off glass - given enough time. We used to use it in a lab I worked in as a replacement for dichromic acid/sulfuric acid solution which was the traditional lab glass cleaning solution.

Plan ahead and let your glass soak and you'll never have to scrub glass again.

dwross
08-20-2010, 10:02 AM
Bill,

Part of the question in your OP referred to the quality of glass required for dry plates. That question has rumbled around in my brain for years, but never floated high enough to prompt the necessary lit search. Thanks for the prompt!

There's not much information. I think it's because glass technology is one of those areas most of us take for granted. But, it has changed considerably since gelatin emulsion was first poured on glass. At any point in the timeline, photographic companies used the best glass-for-the-price available to them. In the 1930 edition (English translation) of 'La Technique Photographique', L.P.Clerc wrote:
"The glass used in the manufacture of photographic plates is specially manufactured, and is, in fact, the monopoly of certain Belgium firms. It must be fairly flat, of uniform thickness, almost colourless, and as free as possible from bubbles or black spots. These qualities are rarely united in one glass, even in the highest qualities for picture framing, which are of much better quality than window glass. The sheets of glass, received in crates, are sorted according to thickness and quality, and stored for distribution as required." p152.

It's unclear what technique(s?) were being used to make the glass.

In Clerc's 2nd edition (1937/1946 reprint) he added a footnote: "Drawn glass, which is now beginning to be more widely used..."p157. According to the Wiki machine, 'drawn glass' (Fourcault process) was developed in Belgium in the early 1900's. About that time, machine-rolled glass became more available. It was cheaper than hand-rolled glass, but the initial capital investment was huge, and only a few companies were involved. Float glass, which is probably all most of us recognize as sheet glass, wasn't invented until the 1950's.

Back to the issue as far as artisan emulsions are concerned -- any green color a glass plate might have won't be a problem worth noting for colorblind/'ordinary' or ortho emulsions, and might even be to a slight advantage.

Photo Engineer
08-20-2010, 10:32 AM
Glass making has changed considerably in the last 100 years. When I was young, window glass had quite a few bubbles and images "rippled" due to thickness variations, so I see the logic in what Denise says - for glass made 100 years ago.

Virtually any good glass today is superior to anything made 100 years ago, and probably even 50 years ago. I used ordinary window glass cut at my hardware store and it worked just fine. The Formulary now supplies 4x5 and 8x10 glass plates for coating.

I should add that Mark Osterman of GEH uses window glass, also with great success.

PE

dwross
08-20-2010, 12:51 PM
...so I see the logic in what Denise says - for glass made 100 years ago.
PE

Sorry, Ron. I don't grasp your point. What logic of what statement?:confused: I use the cheapest glass I can buy. Modern glass is great stuff. If it happens to have a green color cast - no matter. It's what I have always advocated on TLF.

(btw: You might consider reading TLF sometime. Good rag if you are interested in making antique artisan emulsions.)

d
www.thelightfarm.com

Photo Engineer
08-20-2010, 12:57 PM
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.

PE

alexhill
08-27-2010, 12:31 PM
antique artisan emulsions

That is a fantastic phrase! Mind if I hold onto it?


(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.

wildbillbugman
08-27-2010, 04:21 PM
"As long as the distilled water sheets evenly I'm happy. "


Yes Sir,
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.
Bill

dwross
08-28-2010, 07:41 AM
Hi, Alex. Nice to see you here again. Welcome back from camp!

Re: 'antique artisan emulsions'


That is a fantastic phrase! Mind if I hold onto it?

Thanks. Absolutely!.

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?' :D )

Gerald C Koch
08-28-2010, 09:04 AM
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.

Ray Rogers
08-28-2010, 10:46 AM
Hi Gerald!

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....

dwross
08-28-2010, 10:56 AM
Hi Jerry,

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.

d

Ray Rogers
08-28-2010, 11:12 AM
Hi Denise.

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?

dwross
08-28-2010, 11:15 AM
Hi Geral

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, rigerous be they are, are in fact not necessarily perfect. I guess as time goes on we all become wiser....

Hi Ray,

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'.

dwross
08-28-2010, 11:34 AM
Hi Denise.

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?

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!

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.