Add 19 litres of hot water to isolated fuel tank, it’s best if the tank is removed from the vehicle. Add the 1 litre Surfex-HD swill to mix.

Allow the tank to soak for two hours before agitating again.

If the tank is over 20 litres in capacity inversion is satisfactory as there is normally sufficient capacity in the surfex HD solution to deal with larger surface areas.

After soaking all sides for two hours in Surfex-HD, drain the liquid into a container a put aside for further use until saturated.

Add 19 litres of hot water, as hot as you can get it, into a container and stir in 1 kilo of Deox-C.

Stir until every trace of solid crystal is gone. You’ll have increase work if your water is cooler.

Add mix to fuel tank, drain and inspect interior regularly using a torch.

The process normally takes from two hours to overnight dependent on temperature and degree of corrosion. Inversion is possible here too to contact all surfaces.

Deox-C is exhausted once the solution is black. After treatment rinse with warm water and dry.

Fill with fuel as soon as possible.