The pH of Filofax Paper

Well today I sidetracked a little from my Essay book, to do some pH testing on Filofax paper. I had discussed this briefly with Steve from Philofaxy, and decided to try both the cotton cream paper and white paper. For accurate testing, I sampled five sheets of each and am showing my results below.

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Cotton Cream
1: 7.6
2: 8.1
3: 7.9
4: 7.7
5: 8.1
Average: 7.9

White Paper
1: 7.2
2: 7.5
3: 7.2
4: 7.0
5: 7.3
Average: 7.2

So in conclusion, both papers are very close to pH neutral which is encouraging. The Cotton Cream is a little more alkali at 7.9 than the white paper.

Neither of them are verging on the acidic side which is good, and the white paper I have used is from 2003, so it has kept acid free for a substantial amount of time.

All in all – very encouraging!

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Essays, Letters and Poems 1781, vol 6

I feel like I am making good progress with this book and it will soon be finished – best not speak too soon, but it is amazing the detail that goes into the conservation of a book. I suppose once you have done something once, it does then get quicker, but at the moment, this particular book feels like it is going at a snails pace.

With the spine piece dyed as mentioned in my last post, I then moved on to preparing the book for the repacking. This meant creating small splits at the edges of the boards at head and tail, back and front, inside and out – leaving very small pieces of leather on the edges of the board which had to be paired, which should be seen in the photo below. This was to allow the new leather to go underneath the existing leather and over the boards for the backing. The tiny fingers of leather on the edges can then be put down again to keep as much as the original leather in place.

Lifting the corners of the boards
The little foot lifting off the edge of the board

Once the edges were lifted, I pasted the joints to allow the adhesive to soak in prior to lining the spine. At the same time I pasted up the leather. To do this the leather must first be wetted on the hair side and allowed to soak in, it is then pasted on the flesh side and folded in half to keep the moisture in. I then wrapped mine in cling film as our studio is very dry.

Pasting up the shoulders
Pasting up the leather

Once this is done, the spine piece then goes onto the spine and is strongly pressed down onto the spine and shoulders, it is imperative that the spine piece is in the right place at this point as it cannot be moved later. This is where I had a problem as the spine piece was squewhiff when I put it down, so one side was a lot longer than the other, meaning that I now have to trim it when dry to ensure the edges of the original leather go down correctly.

Lining the spine
Pressing the joints

Once the spine and edges are down, the book is taken out of the press and prepare for the end caps. One edge of the spine is folded back on itself and the book placed on end to work on the opposite end cap.

Standing the book on end to do the end caps

Following this the boards are spread to give access to the end caps, and the leather is then folded underneath itself and under the leather on the boards.

Folding in the end bands

It is important that the leather is worked onto the boards evenly, so that will be seen as little as possible. The leather encasing the end bands should be just to the height of the end bands, if not, fractionally higher. The book is then placed upside down and the end cap on the bench, knocked up with a bone folder to give it shape, and the second end cap done. Once both are done, thread is wrapped around the book to produce the shoulders, which should also be worked with a bone folder, so that they are in line with the boards.

Working the end caps

Essays, Letters and Poems 1781, vol 5

So I am back to my Essays book this week which is exciting! I have to admit that I have been a bit nervous about the next few stages of conservation on this one, as I am venturing into unknown territory. However the book belongs to my tutor and come from a charity shop, so I take comfort in the fact that if I completely destroy it, its not the end of the world!

So the next two stages are toning my leather spine piece and repacking the book. After that it will be retouching little bits to make it look amazing! Unfortunately yesterday I had plucked up the courage to dye my leather spine piece that I pared for a whole DAY last term only to find a much better matching piece of calf – so guess what today is – yup, leather pairing again. Dammit.

Anyway, I did manage to practice the toning yesterday and get the right colour, so at least I will be ready to tone next week. If not today if I am super quick!

Bits of toned leather

So I thought I would just update this post with the actual dye ratios – more for my future reference!

Batch 1 – key colour
4 – yellow
1 – brown
25 – water

Batch 2 – touch up colour
3 x yellow
1 x brown
1 x red
50 x water

Tinofix
1 x tinofix
17 x water

Tape & Adhesive Removal

The past week we have been looking at tape and adhesive removal, which is a problem that afflicts most collections of paper and books as owners will commonly stick the odd thing back together with tape – the old make do and mend regime – unfortunately, whereas I am usually well up for this way of life, in this scenario, it tends to do more damage than if they were left alone!

Samples of aged tape on paper to work with

The routine for tape and adhesive removal is the same in all cases and starts with backing removal, then the adhesive and finally the stain (if possible).

Backing Material
These will change for different tapes – brown gum tape, cellulose tape, other sticky back plastic, double sided tape, masking tape, scotch tape – the list goes on! The backing material can be removed with a range of different techniques, which each need to be tested until the best method for your tape is found. Any removal should not be done all at once, a bit at a time is less likely to cause any skinning, and the use of a magnified light can also help.

Brown gum tape
This was the hardest to get off as it is not possible without water which can damage the object, even then some skinning occurred with mine. The best method I found was to scrape away the primary surface of the tape using either sandpaper, or better a spatular. I then wet small areas at a time with hot water and a brush and teased away the remaining backing (keep a tissue handy for the residue). At this point it is good to use cellulose powder to get as much adhesive off at the same time to prevent having to wet the paper again at a later date. Unfortunately some cockling did occur in my case and it was a very time consuming method, and one that needs practice to prevent skinning.

A methyl cellulose poultice on top of some bondina on the tape, will also work. This should reduce the water contact, but may still be enough to remove the rest of the backing. I did not try this method.

Teasing brown gum tape with a spatula

Masking Tape
Masking tape will often come off of its own accord quite readily with careful teasing from a spatular. If difficult, it can be warmed up with a hair dryer and this should excite the molecules enough to let the spatular tease it off without skinning. When using this method, it helps to dip the spatular into a solvent to remove any excess adhesive. Easing the spatular carefully along one side and pulling it up with some tweezers will often do the trick. Unfortunately it will then leave a large amount of adhesive that then has to be removed also.

Cellulose tape and other sticky back plastics
Cellulose tape (eg Sellotape) will curl up when put in boiling water, which is how you can tell it apart from other sticky back plastics. Both of my clear tapes were fairly easy to remove, though this would not be the case with any older tapes. In cases such as this, a hair dryer should be set near the tape, allowing it to warm up, then the tape teased away with tweezers as the adhesive softens and becomes more pliable. It is also possible to scarify the surface and add hot water, though the small amount of heat from the dryer is less likely to damage the paper than water. Double sided sticky tape can be treated in the same way.

Using the hairdryer to tease the backing material off
Teasing the tape with a spatular

Adhesive
The remaining adhesive, once the backing material has come off, is more tricky to remove.  There are several methods which should be tried in order to find the one that best fits the adhesive. The first step is to use dry cleaning methods, which can often be enough to remove all the tack. If this doesn’t work, solvents are used to swell the remaining adhesive in order to allow it to be removed mechanically. The common solvents are IMS, Acetone, Ethyl Acetate, Isopropanol and Toluene – with the exception of IMS, all of these should be used in a fume cupboard. Toluene is not used in most institutions as it is toxic to pregnant women, so beware! Using each of the methods below, different solvents will need to be tested to see which works best for the adhesive removal.

Acetone
Using Tolulene in the fume cupboard

Dry cleaning
Cellulose powder is an excellent start for the first stages of removing adhesives, as it is made from loose fibres that are the primary form of paper. When put on the adhesive, the fibres will stick to the adhesive, both can then be manipulated with a spatular and removed. Crepe rubbers are also used in dry cleaning, as they will pick up the adhesive also, though can be quite rough and will damage the paper surface if not used correctly.

Methyl Cellulose Powder

Solvent cleaning – method 1, using a poultice
– Place a laponite poultice onto some remay and place that onto the adhesive. Laponite is similar to methyl cellulose (which can also be used) but it is not so wet.
– Feed the poultice with the chosen solvent to allow it to swell the adhesive.
– The solvent can sometimes leek over the poultice and get onto the object, this can be prevented by surrounding the poultice with laponite powder.
– The poultice should be covered with melinex and left for 15 mins, during this time it should be continually fed with the solvent.
– After the 15 minutes are up, the swollen adhesive should then be mechanically cleaned with a spatular.
– Once all adhesive is removed, it will need to be flushed through on the vacuum table.

Solvent cleaning – method 2, using blotter
– A similar method as above, where blotter is used instead of a poultice.
– Cover the object with a small piece of sympotex
– Place blotter on top of this, which has the desired solvent dripped onto it (not drenched)
– Melinex then goes on top of this and it is left for 15 mins, during this time it should be continually fed with the solvent.
– After the 15 minutes are up, the swollen adhesive should then be mechanically cleaned with a spatular.
– Once all adhesive is removed, it will need to be flushed through on the vacuum table.

Making a small solvent chamber with blotter

Solvent cleaning – method 3, using a solvent chamber
This is the most gentle use of solvent as it only uses the vapours, and does not need to be flushed through on the vacuum table.
– Wedge some blotter into the base of a beaker and spray with water to humidify
– Place this upside down over the adhesive area and allow the water vapours to form and reach the adhesive, which may take 10 mins
– Introduce the solvent to the wedged blotter and place back over the adhesive
– Keep feeding the blotter over a 15 min period
– After the 15 minutes are up, the swollen adhesive should then be mechanically cleaned with a spatular.

Making a small solvent chamber

Staining
Staining is the hardest part to remove, and will often have no effect. Rubber adhesives sit on the paper fibres and can be removed to some extent, though acrylic adhesives will get into the core of the paper – the adhesive can be swollen and removed, but stain will remain. The method is to flush through the adhesive with a solvent on the vacuum table, which needs to be done anyway with methods 1 and 2. The object should be placed adhesive down onto some cotton fabric so that it can be absorbed out of the object rather than through it and the area to be flushed should be masked with melinex. Once the vacuum is on, try each solvent, as with the adhesive removal, in order to find the best one. This solvent should be continually fed to the object without letting it dry fully, or get too wet. If it does not remove the stain, it should certainly remove the tackiness.

Tests I have done
Cellulose tape – backing material came off with a hairdryer, the adhesive came off with an Isopropanol poultice and the stain was lightly reduced with Ethyl Acetate.
Gum tape –  backing came off by scraping the top surface, then slightly wetting areas and scraping the remainder with a spatular. Cellulose powder got off the adhesive when added immediately whilst it was still damp. There was no stain.
Masking tape – backing cam off with a hairdryer, the adhesive came off with cellulose powder and a crepe rubber. There was no stain.
Scotch tape – backing and adhesive came off from teasing away with a spatular. No adhesive or stain remained.

Toluene – This is a good solvent for rubber based adhesives
Ethyl Acetate – Removed some of the stain and a little translucency from adhesive that had made the page transparent.

 

Paper washing and bleaching, vol 2

The second part of my washing and bleaching post is more about the bleaching part. As mentioned in the previous post, this is rarely done in conservation as it is thought to damage the structure of the paper fibres and will continue to disintegrate the object if not denatured properly. As before we were also measuring the experiments as we went to see the difference in paper weights as they were cleaned.

Sodium Dythonite (EDTA), Hydrogen Peroxide, Calcium Hypochlorite

There were three forms of bleaching we used in this session – Sodium Dythonite, Calcium Hypochlorite and Hydrogen Peroxide.

Spot testing the different bleaches

Sodium Dythonite at pH8
Conservators will us Sodium Dythonite to a certain extent, and will often prefer this solution, however it is often not removed totally and can leave a residue in the object. Similarly to this, conservators will often reuse this solution on the same spot many time over in order to remove a stain, however this repetitive use of the solution can be much more damaging than using a stronger one, such as Calcium Hypochlorite, to begin with and ensuring it is removed in full.

20g of Sodium Dythonite into EDTA (unknown amount)
Adjust the pH with Sodium Hydroxide until pH 8 is reached
This required a large amount of Sodium Hydroxide, possibly as the strength of the latter and the amount of EDTA was unknown.

Calcium Hypochlorite at pH9 (bleach of choice)
This solution often has a bad name, though we have been told it does not diserve such a reputation. It is argued that chlorine may be left in the object after de-naturing it (washing through with water). This is chemically suspicious as chlorine is linked to calcium and the molecules are strong and generally stay together. Once the calcium is removed, the chlorine will have nothing to attach to and should come off as a gas.

200ml of 4% Calcium Hypochlorite into 600ml of water
Intial testing of pH showed it at pH10.5
10% Acetic Acid was added to bring the pH down to 9

Hydrogen Peroxide at pH9
When it is used on objects, it will bleach as it drys due to unstable H2O2 molecules, which will release the spare O as a gas, denaturing itself in the process. However a conference in Vienna argued that this did not always occur and peroxide was left in the paper causing continual damage, it is therefore no longer used.

3ml of 3% Hydrogen Peroxide into 23ml of demonised water
The pH is altered using Ammonia to reach pH9
This should bring the amount up to 30ml

We then used each of these bleaches, mostly the Calcium Hypochlorite, and tested methods of cleaning. Everything was done on the vacuum table, having first humidified the object, and thoroughly washing it throughout. We used small amounts on a brush to target small stains such as foxing, and also spraying specific areas by masking the object with melinex.

Calcium Hypochlorite used on a masked out area
Half and half on the same sheet (using bleach of choice)

In the case of immersion, the whole page was put in a bath of Calcium Hypochlorite and then washed in water and left to dry.

Immersion into a bath of 4% Calcium Hypochlorite
Before immersion
After immersion


Testing pH

Similarly to the recent post on paste, this is another self indulgent post, designed to remind myself of techniques I have used for the future when my brain starts to forget them!

pH is necessary to test on any number of occasions, for any number of reasons. Our recent washing and bleaching session saw us testing the pH of paper before and after doing experiments on the pages of a book. There are are also various methods of testing pH, though I am only looking at the one here at the moment.

Testing pH using a Probe Meter

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Before starting to test the object, the machine must first be calibrated. Once calibrated, it can be used for a day or so, but after leaving for a period of time, it must be calibrated again. The picture shows two pippett jars and two small pots. One jar has an acidic solution with pH of 4, and the second with a neutral pH of 7. A small amount of each solution is put in each small pot and the pippett jars can then be put to one side.

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The probe is kept in an airtight pot with a small amount of deionised water to keep it safe. The next step is to remove the probe and dip it into the pH7 pot. At this point the machine should then be altered so that the dial rests on 7. The probe is then washed with deionised water and dipped in the pH4 pot, again the dial should be moved to meet four.

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This is repeated until the dial no long needs to be moved. The machine should now be calibrated.

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Once calibrated, it is very simple to test the pH. Although one stipulation for this method is that the tested item has to be wet. If testing a dry object, a drop of water can be dropped onto the object and left to soak in. The probe is then rinsed in deionised water and placed on the object, and the reading taken.

Obviously one negative point of this process is that there is the possibility of tidelines, so if it is possible to test whilst humidifying anyway, the risk will be much reduced.