Wet Work - Washing, Deacidification & Bleaching

Charlie · April 2014

Matt said:

Re: Wet Work. How long do you bathe the poster? Daybills being thinner than one sheets would have less time in the bath?

Charlie said:

Great question. Not really, for say the initial soak and deacidification. I am at 20 to 30 minutes before my first rinse after the CaOH pretty much any poster. However, a byproduct of the CaOH turns the water yellow (maybe brown - I am color blind) and if that happens to a significant degree, I will do another 20 minute soak... Now for bleaching, it's all a big babysitting job, you never leave it. Unless, you want to be really conservative with a weak solution that takes a good hour to work... It's usually a 15 minute event, unless there are spots that need attention... There are actually two methods I use. Let me get to a desktop and I will discuss those.

Charlie said:

Ok so the two methods.

Method 1: Complete Immersion

This is taking the poster(s) and placing it in a tray, or the like, with a solution that has been calibrated to a pH level 10-12. Leaving it for the prescribed time.

Here is the "left-overs" from a set of daybills I did for you. I soaked them because they are smaller and the tray is manageable.

Method 2: Spray On Method

This is taking the poster against a mylar sheet and after it had been completely made wet and excess water mechanically removed - soaking the poster with by spraying a prepared solution (g/L) on both sides and sustaining the presence of that solution between two mylar sheets. This is actually easier and more difficult because you have to respray in 5-10 minute intervals to ensure that the poster remains completely wet with solution. If it does not remain completely wet discoloring may appear as the CaOH solution does act as a mild bleach as well... It's a constant babysitting job but one where you are only preparing a 1L solution versus a 10 liter bath that is then pitched.

FYI here are some common deacidification methods that someone my find of interest:

Charlie · April 2014

Let me know what else you guys want to know about this area of the process!

Best,

Charlie

Charlie · April 2014

More from the starter thread:

Charlie said:

So the for "Wet Work" I want to add more about process...

For the bleaching compound I use, Calcium Hypochlorite, it is important for the paper to already have alkalinity for it to work properly for a few of reasons.

One is that a deacidification bath before bleaching helps with foxing, sometimes it removes those little pest of spots before bleaching all together.
Second is inactivates metal ions in the paper. Third is raises the pH so that when the acid byproduct lowers the pH degradation does not occur.

So what does this mean? Ever wonder why conservators charge more for bleaching?

Well if done by the following method one can figure it out right away - it's a lot of work!

Step 1: Deacidification with Calcium Hydroxide (Raises pH & give poster some alkalinity) 30 min
Step 2: Bleach with Calcium Hypochlorite (Reaction with substances in paper such as albumin, sizing, chromophores and etc. create chloramines and more acidic environment) As Desired
Step 3: Spray Acetic Acid to neutralize any unreacted chlorine and chloramines creating hydrochloric acid. 5 Minutes
Step 4: Deacidify the poster again with Calcium Hydroxide (you actually see solid Calcium Chloride leaving the poster)

Washing between each step...

I've not used Hydrogen Peroxide but have used Chloramine T but in literature it has fallen in disfavor because of the difficulty in removing it from the paper and the lack of control after rinsing.

What shall we talk about next time?

Upper_Shelf · July 2014

Question, do you use Deionized water, or would purified work?

Thanks

Charlie · July 2014

Well, you can use a bit of both. Usually treated/purified for large washing but distilled/deionized (although not exactly the same) for wheat paste and chemical prep and my preference for the final rinse portion of the poster prep. The main key is to have the water microbe free for that which will stay in the paper such as wheat paste...

Deionized (vs. destilled) can have some extra benefit when washing because it can strip the poster of calcium, magnesium, and some acids... but overall not very good in removing acids during a wash, so that should be left up to the deacidification process.

racer59 · November 2014

When you did use Chloramine T for bleaching. What was the ratio you used for you solution? The most I have used, and has been the best was 20 teaspoons to 1 liter of water, only problem is everything smelled like bleach for the rest of the day even after rinsing

Charlie · November 2014

Never went that strong... It's been years since I did use it so I couldn't tell you. Maybe at the most 5 spoons/liter...

racer59 · November 2014

Thanks. I haven't tried anything good yet with lots of color, still trying to work the solution and get an ideal mix. I'm finding, it's all a matter of time.

racer59 · November 2014

I'm finding out bleaching can be really hard depending on the paper, all the one sheets I have done have really been difficult, I washed a french one panel and it was magical, bright and clean.

racer59 · November 2014

Still wet, tried to embed a picture. Didn't work

David · November 2014

racer59 said:

Still wet, tried to embed a picture. Didn't work

It will - are you using Photobucket or similar?

Also read here: http://vintagemoviepostersforum.com/discussion/85/posting-images

And here (just for fun): http://vintagemoviepostersforum.com/categories/hey-newbie-

racer59 · December 2014

Ive been reading up on Calcium Hypochlorite as an alternative to Chloromine T, but it seems like a pretty serious chemical. How hard / dangerous is it to work with and is it easy to obtain locally? Talas has to ship it as hazardous material.

Charlie · December 2014

It's a secret... You have to make a thread and show us what you have been working on and then I'll PM you.

racer59 · December 2014

You got it bud. I'l make a thread when I get off of work on the poster that I worked on this last weekend. Its the only one I have taken pictured on from start to finish.

Matt · October 2015

Can you summarise bleaching and spot bleaching please?

Charlie · October 2015

Clorox and more Clorox...

I'll sit down tonight and write something up.

Charlie · October 2015

Charlie said:

More from the starter thread:

Charlie said:

So the for "Wet Work" I want to add more about process...

For the bleaching compound I use, Calcium Hypochlorite, it is important for the paper to already have alkalinity for it to work properly for a few of reasons.

One is that a deacidification bath before bleaching helps with foxing, sometimes it removes those little pest of spots before bleaching all together.
Second is inactivates metal ions in the paper. Third is raises the pH so that when the acid byproduct lowers the pH degradation does not occur.

So what does this mean? Ever wonder why conservators charge more for bleaching?

Well if done by the following method one can figure it out right away - it's a lot of work!

Step 1: Deacidification with Calcium Hydroxide (Raises pH & give poster some alkalinity) 30 min
Step 2: Bleach with Calcium Hypochlorite (Reaction with substances in paper such as albumin, sizing, chromophores and etc. create chloramines and more acidic environment) As Desired
Step 3: Spray Acetic Acid to neutralize any unreacted chlorine and chloramines creating hydrochloric acid. 5 Minutes
Step 4: Deacidify the poster again with Calcium Hydroxide (you actually see solid Calcium Chloride leaving the poster)

Washing between each step...

I've not used Hydrogen Peroxide but have used Chloramine T but in literature it has fallen in disfavor because of the difficulty in removing it from the paper and the lack of control after rinsing.

What shall we talk about next time?

This is bleaching..

Eisenhower · October 2015

Cool. Prior to washing a poster-what visual elements/poster attributes make you decide, I'm going to bleach this poster? Or not bleach a poster? Just curious...Thanks!

Charlie · October 2015

Spot bleaching can be done in many ways. The one remaining way I would like to try is by using a vacuum table. But I don't have a vacuum table.

I have in cases treated specific areas of a poster (i.e. stains) by adding stronger bleach to that area with an eye dropper. Sometime bleaching simply doesn't work. The stain may require a solvent of some sort... Stains can also be affected by the pre-treatment. It's sounds weird but bleach will work better if the piece is properly deacidified. There is some chemistry involved in this allowing the yellowing agents to be destroyed and/our reacted out.

Charlie · October 2015

Eisenhower said:

Cool. Prior to washing a poster-what visual elements/poster attributes make you decide, I'm going to bleach this poster? Or not bleach a poster? Just curious...Thanks!

Just a gut feel. Unless the poster just looks like old newspaper I wait until I've deacidified it. The deacidifying agent is a lite bleach itself so If the poster looks really dull after that treatment I will move forward. I know some restorers are very cautious with bleaching. I've not really come across a poster I wouldn't bleach, because I am fairly confident I can react out the chems. I've never had a poster go fragile on me after bleaching it.

Eisenhower · October 2015

Makes good sense-I have a US one sheet Outlaw Josey Wales that has a very light yellow tinge in the main area, not showing in about a 1-inch border all around the poster-like it was folded inwards when displayed. If deacid doesn't fix, then bleach. Thanks.

Matt · October 2015

How much Calcium Hydroxide do you use?

Matt · October 2015

I found this an interesting read.

http://www.philobiblon.com/gbwarticle/gbwjournalarticle.htm

Eisenhower · October 2015

Good read, Matt. Good section on tape & alkalization. Bleaching ever controversial as they only recommend on chemical treatment & favor light bleaching as the safe alternative.

Charlie · October 2015

BS... Bunch of pussies...

Eisenhower · October 2015

Now don't sugar-coat it, how do you really feel about the Printed Book Materials people?

Matt · October 2015

Trying my hand at washing posters here's my first effort. Overall pretty good result. Water was very dirty, there are still are few stains still visible. I'm still waiting for bleach to arrive from the supplier

Before