Soda anyone?




The best way to fully assess corrosion under the paintwork on a classic car is of course, to completely remove the paint and look directly at the steel.

This sounds straightforward and there are a number of ways to get paint off but each one has its drawbacks.

Shot blasting generates heat that can easily distort old metal. It is also very inaccurate and will destroy any chrome plastic and rubber in the vicinity.

Chemical dipping will strip the paint off but it will strip everything else off as well, so the entire car has to be disassembled. Also, the chemical agent can get trapped in pockets and can reappear after the car has been refurbished, stripping off the new paint finish as it goes.

Sterling Automotive uses a technique known as soda blasting to remove paint. It involves blowing a jet of soda (yes, it really is the same soda that is used in cooking) at the paint under low pressure. It is so gentle that it creates almost no heat. Furthermore, the car does not even need to be stripped at all. The operator can carefully blast right up against chrome, rubber and plastic trims without causing any harm.

Unlike other techniques, very small areas can be singled out for taking back to the substrate. You can choose to remove rust, filler and fibreglass etc or leave it in place for dealing with during the repair process.

Another bonus with soda blasting is that it is so gentle when correctly done, that it does not break the surface tension of the bodywork steel, so the car can be left for weeks or even months in its bare state without rusting. In fact, because soda is completely water soluble, when we strip a car using this medium, the first thing we do is rinse it with clean cold water and leave it to air dry.

We are displaying a 1966 Mercedes 250S that has had the lower half soda blasted, at the 2009 Classic vehicle show at Newbury Racecourse on August 9th. We would be very happy to discuss the technique with any visitors to the show.