There are various products available on the market today to remove graffiti. Graffiti removers and other chemicals can be purchased at your local hardware store or paint store. There are some other ways to remove graffiti which do not include household cleaners, chemicals as they can be harmful to your property.

The first thing you can try is to use a pressure washer. To complete the project like that you are going to need a Petrol High Pressure Cleaner Machine (3000 psi) to achieve the best result. Pressure Cleaner Machines (3000 psi) can be hired from many companies on a daily bases. It is worth hiring a machine and get a better result then purchasing some cheap pressure cleaner at your local store. They are powerful machines and were designed for projects like that. It could also save you some time if you are working with a professional pressure cleaner machine. The pressure cleaner has to be at least 2600 psi. If it is less then 2600 psi you will not get the required result. Also keep in mind that you do not use more then 4000 psi because it may damage the surface. If the graffiti is on a weather board wall and the wall is in poor condition do not use the pressure cleaner on the surface as it will damage the boards. Do not point the pressure cleaner to anyone or breakable items. Windows could easily break in seconds so try to avoid hitting them. If you are cleaning wood or any other soft surface, be careful not to point the gun into one spot for a long time. 

Another easy way to remove the graffiti is simply Paint over them. If the graffiti is on a fence or exterior wall, painting the surface can be a really easy solution for everyone.

You can try Graffiti Rid GR007 Graffiti Remover Product. It is an Australian made product and also easy to use. There are many other brand name products on the market today. Products are available at your local hardware store or paint store.

The last thing you can attempt is Chemicals. Please keep in mind that chemicals should be used in a well ventilated area to avoid inhalation of the chemicals. You might want to consider hiring a professional for this.

It should be noted that the graffiti should be removed from all substrates as quickly as possible because if it is allowed to cure over a period of time it can be more difficult to remove.

Removing Graffiti from Colorbond Steel:

Please keep in mind that Chemicals such as Acetone, Methylethyl Ketone, Toluene, Thinners or commercial Paint Strippers used as graffiti removers must never be used on Colorbond Steel. 

There is a graffiti removal product which has been shown to be effective in removing graffiti from Colorbond Steel. The product is DuPont Graffiti Remover (EZ-3463™). It is a non hazardous, biodegradable water based product, which can be sprayed on the affected surface with generally good results. DuPont Graffiti Remover (EZ-3463™) can be purchased from suppliers of fencing made from Colorbond Steel, or from most Bunnings Warehouse hardware outlets.

It should be noted that the graffiti should be removed from all substrates as quickly as possible because if it is allowed to cure over a period of time it can be more difficult to remove.