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!

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.

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.

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.

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.

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.

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.

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.
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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.