At a time when few people gave much thought to films after the end-titles rolled, Harold Brown set out to make sure that future generations would be able to see and enjoy footage as varied as a documentary record of King Edward VII’s funeral procession and the Douglas Fairbanks silent swashbuckler The Black Pirate (1926).

He was one of the world’s first film archivists. He laid down principles and practices that shaped the profession today. A self-taught pioneer, he used string, rubber bands and bits of Meccano — the engineering toy that was once a standard Christmas present for boys — to build a printer to copy early films. He was also the longest-serving employee of the British Film Institute, having begun work there at 15 in 1935, not long after the organisation was set up, and retired in 1984, aged 65.

In an industry that produces more than its fair share of celebrity excitement, the post of archivist might seem to lack glamour, but Brown was lionised within the business. “He is genuinely a hero of film archiving, who established many of the working methods upon which the National Film Archive and other archives around the world were based,” said Luke McKernan, who worked with Brown at the National Film Archive and is now curator, moving image, at the British Library and runs the website The Bioscope.

The BFI director Amanda Nevill credited Brown with saving thousands of films for the nation, while Eve Watson at the Living Archive in Milton Keynes was inspired, by hearing Brown talk, to follow in his footsteps, studying film archiving at East Anglia University, a course that Brown helped to set up.

Harold Godart Brown was born in the London borough of Walthamstow in 1919. His father made nautical instruments, thus providing Brown with an early insight into mechanics. The BFI was founded in 1933 and Brown joined two years later as an office boy.

One of the objectives was to establish “a national repository of films of permanent value”, and Brown served as assistant to Ernest Lindgren, the curator of this new National Film Library (subsequently the National Film Archive and now the BFI National Archive). The two of them collected the first 40 films (from the Society for Psychical Research) in May 1935, a collection that included various pieces of factual film, including footage of George V’s visit to Delhi in 1911, an early Stan Laurel short and a cartoon featuring Bonzo the Dog.

The BFI library was one of the first film archives in the world, though archives were established in Paris, Berlin and New York at much the same time by a group of enthusiasts, all learning as they went. It was significant that films had acquired sound just a few years earlier. Silent films no longer had any commercial value, they were regarded as worthless by film companies and the entire back-catalogue was in imminent danger of disappearing forever.

The Second World War threatened the archive work. Brown was a conscientious objector, as his father had been during the 1914-18 war, but served with the Friends’ Ambulance Unit.

In 1951 he became the BFI’s first film preservation officer. Collecting film was only part of the work of the expanding archive, and Brown did much to preserve, restore and duplicate both early, highly combustible nitrate films and later acetate films, which had problems of their own that became apparent in later years.

He coined the phrase “vinegar syndrome” to describe the acidic deterioration of acetate film and developed artificial ageing tests to enable archivists to determine when films were likely to start deteriorating, allowing them to prioritise certain films and make their plans accordingly.

His contribution to film archiving was recognised when he was appointed MBE in 1967. He retired from the BFI in 1984, but remained a key figure in the field, as a consultant, mentor and author. His books Basic Film Handling (1985) and Physical Characteristics of Early Films as Aids to Identification (1990) remain standard works.

Brown’s wife, Joan, died last year, and he is survived by three children.

Harold Brown, MBE, film archivist, was born on August 15, 1919. He died on November 14, 2008, aged 89