Volatile–
Cyclododecane Spray 
Basic Information Last Update 11/99
Cyclododecane is a wax-like, water-repelling and un-poisonous substance. It has the amazing characteristic to simply vanish by evaporation (sublimation) after a few days.
From slowly evaporating solvents CCD produces a kind of felt consisting of long, needle-like crystals. This film offers only little resistance to mechanical pressure.
The quickly subliming solvents build an amorphous precipitation, developing into a film getting thicker and thicker by the time. This film is absolutely water-proof, it also offers mechanical protection. As a rule you can say, that on porous, non-sucking surfaces the density of the film as well as its ability to resist mechanical pressure increase with the volatility of the used thinner
In contrast to the applications used so far, melt and solution, the usage of cyclododecane as a spray represents a third form. Inside the spray can cyclododecane is present in a solved form. In this case the propellant is the only solvent. Additional solvents are not present.
The propellant, being an extremely volatile solvent, also determines the main characteristics of the cyclododecane film.
Spraying Distance: Important!
Because the propellant dissolves rather fast from the fluid into the gaseous state, the
cyclododecane , dissolved at first, precipitates in a solid state. That part of the gas that is still fluid
in the sprayed fog when exiting the spray can gets less and less with growing distance to the
nozzle until only the pure cyclododecane dust is left over.
To end up with a film that is as dense as possible, the distance between nozzle and object should be as short as possible.
To get a film that does not rub off a distance of 3 to 4 cm is recommended.
You will get a soft but very even film with a distance between 6 and 10cm.
Larger distances will lead to films that come off easily. They also lead to high loss.
Spraying Direction onto Horizontal Surfaces (To the Top or to the Bottom)
Spraying vertically to the top or even directly downwards is absolutely possible, but not the standard procedure. In order to get an even, not-changing spray you need to turn the nozzle until the lower end of the rising pipe inside the can submerges into the material. As this pipe always touches a side of the can, it is possible to totally empty the can even in a horizontal position.
Characteristics of the Film
Basically the sprayed film stays on any surface. Be it a textile, wood, glass, varnished areas, metal, plastic or other material, but also porous surfaces like stone, mortar or paper.
The characteristics of the film differ from that of the melt. It is a rather amorphous film with a mechanical solidity mainly depending of the distance of spraying. It does not reach the density nor the solidity of the film from a melt. From the moment of applying it the solidity increases. The individual dust particles condense more and more.
The protective effect against water and watery solvents is safe. However, any addition of a wetting agent has the effect that the sprayed film can be penetrated.
Whereas the melted film offers perfect protection against all highly polar solvents, the sprayed film is penetrated easily by polar solvents like ethanol, isopropanol or acetone, without being solved itself.
Depth of penetration
With porous surfaces the question of the depth of penetration certainly is of importance. Whereas the ability to penetrate of both melt and solution is rather great, that of the sprayed film is near zero. As the sprayed film doesn't penetrate into the surface it doesn't have any protective effect.
Reversibility
The characteristics of the sprayed CCD-film also determines the rate of evaporation.
A melt with a 1mm film needs about 30 days to totally evaporate, whereas a sprayed film evaporates distinctively faster. A 1mm film will totally disappear in 2 to 3 days at 20°C. On façades without direct sun the same film may disappear within a day.
Instant removal of the Cyclododecan film
In some situations you would like to be able to remove the film without having to wait until it evaporated. Spraying or brushing of petroleum spirit makes this possible without a problem. On sensitive surfaces you should use petroleum spirit without aromatic additives. I can recommend Exxsol 100-140 by Esso.
Main field of application
The main field of application certainly is the temporary protection of sensitive areas.
Using a spray can has big advantages when a quick evaporation of the protective film is desirable after one or two days and if a quick, uncomplicated application is important. Another advantage is that you can achieve an even, regular thickness of the film even on large areas.
Of course a sprayed cyclododecane film can be melted in. I recommend using a heating lamp or a heated spatula.
For small, local consolidations or seals with CCD-melt I use a CCD-coated foil as a transfer paper. For this purpose a hostaphan (polyester) foil is coated using a spray can and cut into strips of usable length. Using a heatable spatula you can then apply it where needed.
Good experience has been made with the following applications:
Protection of sensitive areas when working with water, and watery solvents, coatings containing water, etc.
Protection of sensitive areas when working with glue containing water or injection mortar.
Protection of sensitive areas when working with plaster and mortar of all sorts
Nozzles
Basically you use different nozzles for different forms of application.
The standard version of the can is fitted with a round (yellow) nozzle to spray with. A spraying distance of 6cm (nozzle to surface) will spray a film on a strip of about 15mm .
To spray areas a fan-like nozzle (red) is supplied. It has a variable exit, so that the angle of spraying can be adjusted individually.
A spraying distance of 6cm will spray a film on a strip of about 50mm.
Consumption
An unambiguous statement as to how much area you can spray with one can is not really possible. The density of the film as well as the spraying distance play a major role, off course. Roughly you can expect that a 400ml can is enough for about one square metre of surface.
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LiteraturE
H.M. Hangleiter – Elisabeth Jägers – Erhard Jägers: Flüchtige Bindemittel, in: Zeitschrift für Kunsttechnologie und Konservierung 1995/2 S. 385-392
Gudrun Hiby: Das Flüchtige Bindemittel Cyclododekan, in: Restauro 1997/2 S.96-103
H.M. Hangleiter: Erfahrungen mit flüchtigen Bindemitteln Teil 1, in: Restauro 1998/5 S.314 - 319
H.M. Hangleiter: Erfahrungen mit flüchtigen Bindemitteln Teil 2, in: Restauro 1998/7 S.468 – 473
Georg Hilbert – Nicole Riedl: Cyclododekan im Putzgefüge, in: Restauro 1998/7 S.494 – 499
Cornelia Bandow: Cyclododekan in der Papierrestaurierung, in Restauro 1999/5 S.326 –330
Gudrun Hiby: Cyclododekan als temporäre Transportsicherung, in Restauro 1999/5 S. 358-363