Can my sign be installed onto a glass surface?

When asked if a sign can be installed against a glass surface, I am always tempted to immediately say YES, signs can be installed onto almost any surface, but I have learned to temper my enthusiasm, as simply saying YES may give the designer, and / or the buyer, incorrect and false hope.

While MOST signs – both internal and external – can be installed against glass, among the factors that need to be considered are the following:

Will the sign be inside or outside?

If outside, will the sign be exposed to rain and direct sunlight?

Will the sign be exposed to water, either from washing or weather?

What look is being sought and material will be used to manufacture the sign?

What is the weight of each element of the sign?

Will the sign be attached to GLASS, or some other clear ‘glass’ like product?

How long is the sign intended to last?

Will the sign be viewed and visible from both inside AND outside of the glass?

While there are a number of excellent adhesives that can fix almost any material to glass, so long as the material being fixed to the glass is not too heavy per square centimeter, certain adhesives will only work indoors, others work best outdoors, and with a number of the adhesives the rear of the sign will look unsightly, while possibly being read backwards. Still other adhesives are so strong that the only way to remove the sign may be to replace the glass, which can become a costly exercise if the glass sheet is very large. My point is there are a number of variable factors that MUST be considered BEFORE a sign is attached to glass.

If the sign is to be located outdoors then the adhesive must be able to sustain weather changes (extreme temperatures) as well as direct sunlight and rain.

Other factors to consider when attaching signs to glass include the size of the sign, especially the area that makes contact with the glass, the weight of the signage element, and the ‘coefficient of change’ of the material of the sign. Simply stated the coefficient of change is the difference in the expansion and shrinking properties of the sign material and the glass, as well as the adhesive, as if the coefficient is too large, the glass is likely to break. For example, if a strip of Aluminium is attached to a glass sheet, and the Aluminium heats up faster than the glass, and the adhesive is too rigid, the Aluminium will effectively pull the glass apart with the pressure points being where ever the aluminium is attached to the glass.

Then same could apply if the material that is attached to the glass is a plastic based product which can be expected to expand a mere 1.6mm over a three meter length when it heats up sufficiently, that expansion could be enough to break the attached glass if the glass expands much faster, or much slower.

As it is with water and electricity, it almost goes without saying that the above comments are even more relevant when water is thrown into the equation of the coefficient of change, especially if the water is in the form of a sudden storm – as is common during the South African Highveld summer afternoons – when the glass and the substrate are already at their warmest, and the sudden cooling of the rain add an additional element to what can be an already pressured ‘relationship’.

When referring to GLASS signs, a lot of people do not necessarily mean glass, but are instead referring to a transparent substance – such as Plexiglas, Acraglas, Ultra High Impact or Perspex, all of which have one property similar to glass – they are transparent – but can often be more easily worked and can have the edges polished to give a clear view. Some ‘plastic glass’ products are resistant to hard knocks – they are not as brittle as glass and will not break on impact and are less likely to suffer from the effects of coefficient of change – but plastic based substrates do tend to scratch more easily, although the scratches can also be more easily worked away.

To sum up, most signs can be attached to a glass backing, but it is important to do your homework before attaching signs to glass, in order to make sure that the adhesive and the sign are compatible and give you the results you intended.

If you are thinking of getting a ‘glass’ sign, a sign attached to glass, are in the market for professional looking signs, or simply require advice on transparent signs, and you wish to get a return on your investment in your sign, act now and email arnold@signforce.co.za or david@signforce.co.za using the subject line: ADVICE PLEASE

http:www.signforce.co.za