Rust

Rust kills cars. That was true 40 years ago but much less so nowadays. As I’m interested in automotive technology I was an involved outsider before I became professionally involved in the 80’ and 90’s. I bought my first new car in 1971 and I was concerned to retard corrosion. I managed to get it Tectyl protected by Valvoline which was based on Merseyside.

This kind of aftermarket treatment was fairly common back then with Ziebart probably the best known brand name. This was far more than undersealing as it involved spraying rust preventive fluid into the semi closed sections of the body such as the sills. Manufacturers were not paying the attention they should and after the switch to monocoque bodies there were some particularly notorious examples. The early Vauxhall Victors were bad and the Lancia Beta had to be withdrawn it was so poor.

Prior to this time in the early fifties cars were built on chassis and body panels were relatively easily replaced. The chassis was usually very thick steel and corrosion wasn’t a big problem. With a monocoque body where almost the whole of the body was structural and was all made from fairly thin steel sheets spot welded together corrosion became a big  problem. A new monocoque body was very strong but was easily weakened by corrosion.

I started my professional interest in corrosion protection in the early 80’s. By that time manufacturing had improved such that aftermarket protection was dying. Castrol was abandoning the market and my main attention was protection during production. As far as body panels were concerned they were pressed and assembled fairly quickly. One product I was quite proud of was a washing product post pressing which protected in the factory for up to week. The panels had to be washed to remove the press fluid before welding and I thought it was rather neat to be able to provide protection as well as cleaning.

Pressing was for body panels. The standard procedure for thicker parts such as suspension and engine components was to machine from a forged part, wash to remove swarf and cutting fluid and then apply a temporary corrosion protective. Then at assembly wash to remove the corrosion protective and assemble.

There were some neat tricks such as corrosion protective which also dewatered after washing which eliminated a drying stage.

However all of this was during production and it was the assembled car in the customers hands which was the earlier issue. By the time I became involved the aftermarket had almost disappeared. The products for which I was responsible such as underseal were selling much reduced volumes. I wasn’t really called upon to provide improved products in performance terms. A series of improvements to design had much reduced the rusting problem. It is more often obsolescence now that marks the end of a car’s life. The improvements have included -design of bodies to reduce trapped moisture by proper drains, and guards to reduce mud build up in the wheel arches, improved steel with fewer impurities. The widespread use of galvanised steel where for example the whole lower body is made of galvanised metal. Better paint protection which includes all the surface preparation prior to painting.

The end result is that in 2020 you buy a new car and virtually forget about rusting.

My work wasn’t really to improve performance but rather to improve health and safety standards. It had been usual to formulate using solvent based products but this was changing to water based.. In a sense this went back to the very early days when a water  emulsified oil had been an early corrosion preventive. Using this technology the first water based corrosion preventives were developed.

 I always thought our German colleagues had a nice promotional idea. This was to provide throat sweets which said that if the new water based products were used they wouldn’t be necessary. I had the pleasant experience of visiting the Opel factory at Bochum where I was congratulated. It was rather unusual and very special to be thanked by a customer. This did come back to bite me because their specifications were very strict and we had difficulty maintaining consistent quality. As they knew my name I was expected to sort it out. The difficulty was the Opel specification was written right at the boundary of the product performance. I did manage to cobble together an answer but it was never totally satisfactory and periodically batches would fail the Opel test. The real problem was the specification had been written around hand made laboratory samples and production just couldn’t match that standard.

Further development of water based corrosion protectives gave slow progress rewarding massive efforts. This tended to be mainly products to carry rust protective packages in water based carriers. These were emulsions or dispersions. Purely soluble products found a niche such as the press lube wash mentioned above.