^Spray on glass is your solution. Read about it here:
http://www.telegraph.co.uk/science/...glass-the-spray-on-scientific-revelation.html and here's what
http://www.physorg.com/news184310039.html says:
"Spray-on liquid glass is transparent, non-toxic, and can protect virtually any surface against almost any damage from hazards such as water, UV radiation, dirt, heat, and bacterial infections. The coating is also flexible and breathable, which makes it suitable for use on an enormous array of products.
The liquid glass spray (technically termed “SiO2 ultra-thin layering”) consists of almost pure silicon dioxide (silica, the normal compound in glass) extracted from quartz sand. Water or ethanol is added, depending on the type of surface to be coated. There are no additives, and the nano-scale glass coating bonds to the surface because of the quantum forces involved. According to the manufacturers, liquid glass has a long-lasting antibacterial effect because microbes landing on the surface cannot divide or replicate easily.
Liquid glass was invented in Turkey and the patent is held by Nanopool, a family-owned German company. Research on the product was carried out at the Saarbrücken Institute for New Materials. Nanopool is already in negotiations in the UK with a number of companies and with the National Health Service, with a view to its widespread adoption. ...
The war graves association in the UK is investigating using the spray to treat stone monuments and grave stones, since trials have shown the coating protects against weathering and graffiti."
The company (with video demonstrations):
http://www.nanopool.biz/couk/download.htm
What it means? Simply spray spray-on-glass onto exterior brick wall. Tag it. Then get a sponge and with water remove the tags! Invention of the decade!
