Plates coating trouble

[Nodda Duma]

They cooked them for hours and hours during first ripening and then added fresh gelatin. The “adding fresh gelatin” step could have been started to address this specific issue, but would be hard to uncover in the literature.

 

[Photo Engineer]

This does not completely make sense. Think of the early "boiled" emulsions.

PE

 

[Elven Zao]

[QUOTE =“Nodda Duma，帖子：2134247，成员：61906”]我在乔治伊士曼博物馆与尼克交谈过，他实际上在工作室里看到了旋涡的艺术品。更重要的是，他看到乳液在温度下长时间处于静止状态，但是当他能够更快地完成批量处理时。他没有说明时限，所以我们还不知道在什么温度下会持续多长时间。这需要仔细测试。

所以我认为这加强了我在swirly artifacts和温度时间之间看到的相关性。[/ QUOTE]
I have done a lot of texts ，and I notice the temperature may the other point ，I coat the plates at 35℃，keep stiring the emulsion while coating ，make all the tools clean，it become better~

 

[Nodda Duma]

Elven, yes.. those are really good tips that I found helpful as well.

This does not completely make sense. Think of the early "boiled" emulsions.

PE

Yes, I thought of that as well. So I looked carefully at (for example) the recipes from Eder, in Wall (the key word is “carefully” for all the reasons we take Wall with a grain of salt), and the other recipe sources that I could dig out of my resources.

Here is what I note: The boiled emulsion recipes were, without exception, boiled during first ripening (obviously). In those recipes, the make up gelatin is added as the emulsion is cooled to much lower temperatures or to help it cool down. After make up gelatin is added, the emulsion is either immediately cooled down and set, or ripened further for a short time period like an hour at 95F before setting. This fresh make up gelatin is key to reducing the chances of those old emulsions failing. After washing, at least in that time frame, they went through the emulsion batches pretty quickly, either on a line or a team of coaters coating them the old fashioned way.

The other difference between that era and now is the refinement and quality of the gelatin, which may have an impact (I don’t think so, but it’s worth noting as a difference).

My other thought is that the quality of coatings amongst the manufactures varied widely. As a data point, Seeds had the best quality coating in that time, and based on the comment on ammonia soaking their plates on pg 215 in here https://nvlpubs.nist.gov/nistpubs/jres/10/jresv10n2p211_A2b.pdf I don’t think they (or Eastman) used a boiled emulsion recipe. This corresponds to my experience in that the conditions which create swirlies also led to a lower quality coating (noticeable difference in the smoothness of the dried emulsion surface, for example).


For us, it seems the time at temperature after make gelatin has been added is important, but that hypothesis requires testing to verify.

 

[Elven Zao]

This does not completely make sense. Think of the early "boiled" emulsions.

PE

Dear PE
Recently，I have run into some other problems，and I need your advice When I add erythrosin and put the plates into developer（HC110） ，（my recipe from TLF “ammoniacal negtive emulsion”）after 3mins the emulsion turn black without exposure，like heavy dark fog；I tried to making new emulsion many times，but the results are same ；If I didn't add erythrosin，the plate looks like all right，but the grain is very thick。

Recipe Overview:
Gel:2.5g Water:10ml;
KBr 7g KI 1% 15Drops Water 13ml；
AgNO3 6g with 10ml Water 5.5+ammonium hydroxide ；
Second Gel：5.5g Water 15ml；
First ripening in 60 mins，at 40℃； second ripening in 45 mins at 51℃；When the second ripening start , I add 6drops of KBr(10%) and 6drops of Steigmann's solution before the emulsion warmed, and when the ripening time passes 30 minutes ，I add 6drops of erythrosin(2%) till the end.

 

[Nodda Duma]

Elven Zao,

Check your safelights to ensure they are not fogging the emulsion due to the added erythrosine. Kodak 1A safelight filter (deep red) or equivalent is what you want.

 

[Elven Zao]

Elven Zao,

Check your safelights to ensure they are not fogging the emulsion due to the added erythrosine. Kodak 1A safelight filter (deep red) or equivalent is what you want.

Thanks ND~ I use AP orange safelight， I don't know it‘s safe or not for Othro； I only know that it’s safe for my colorblind emulsion ：）

 

[Photo Engineer]

The orange might work, depending on speed, but red is safer in this use.

As for the fog, it might be due to your adding the erythrosine before the wash, at the wrong time. I add it either before any salt is added or after the wash. Remember, with Ammoniated emulsions, you must wash completely and insure that the pH is about 5.5 when done.

PE

 

[Andrew O'Neill]

Those swirly patterns look very similar to what I would get on my carbon tissues if I didn't allow enough time for the glop to gas out. Probably not helpful... but we are both working with gelatine.

 

[Elven Zao]

[QUOTE =“Photo Engineer，post：2135360，member：6399”]橙色可能会起作用，具体取决于速度，但红色在此用途中更安全。

至于雾，可能是因为你在洗涤之前在错误的时间加入了赤藓红。我在加入任何盐之前或洗涤之后加入。请记住，使用氨化乳液时，必须完全洗涤并确保pH值在约5.5时完成。

PE [/ QUOTE]
Thanks PE，I‘ll try with a new safelight：）

 

[Photo Engineer]

什么？ 我不喜欢...