Jenolite & Chemical sealer used on roof girders at TCC’s Acton Factory
Founded nearly fifty years ago, TCC - the Telegraph Condenser Company Ltd. have become the largest firm in Europe engaged exclusively in the manufacture of condensers, and their products are fitted as standard equipment on electrical machinery all over the world.
Often small usually unnoticed, condensers are of course a vital part of an electrical supply system. In alternating current both the circuit voltage and the current flowing follow their own wave forms. If these wave forms are in step, the result is consistent and maximum power. Owing to a number of factors, however, the current tends to lag behind the voltage; and the greater the lag, the greater the loss of power.
Condensers help to synchronise the current and voltage waves and, in one form or another are used on a vast variety of products, from radio transformers to electric razors; and also for maintain the local electrical power in buildings.
Catering originally for submarine cables only, TCC now manufacture paper, electrolytic, mica ceramic, plastic film and special purpose condensers covering the entire field of electricals equipment. Their Acton factory employs about 1,000 workers, while they have another factory in Scotland and associate companies in Australia and Spain.
TCC’s corrosion problem concerned the structural steel in their forming department, which deals with the most important phase in the manufacture of electrolytic condensers. The principal component of these is aluminium foil, which requires the addition of a chemical film. This is electrolytic/ally deposited on the rolls of foil as they move through various processing tanks. Where maximum capacities of film are requires without increase in plate size, the foil is chemically etched.
The solutions in the tanks are heated to high temperatures, and a considerable amount of steam containing alkalis is condensing on the roof trusses.
About six months ago, this steelwork was in seriously corroded condition, with most of the painting system forced off. After a conference with a consultant from Jenolite and the contractors, Messrs. Gaze and sons, TCC decided to experiment by subjecting test samples in the forming department.
Accordingly, a piece of angle iron and a length of 2 ½ inch steel piping were treated with Jenolite RRN and chemical sealer. Then each was divided into 4 sections. The first quarter was left as it was. The second was given one coat of black bituminous paint; the third received two and the fourth, three coats.
Both items were suspended from the roofs over one of the largest processing tanks, and left there for 3 months. At the end of this period, in July, 1954, the metalwork was examined. The jenolized sections with chemical sealer only showed evidence of corrosion, while blistering had appeared over the section with only one coat of paint. It was decided nevertheless, to select the three-coat painting system as a pre-cautionary measure. Following these tests, half the roof trusses and some main girders (RSJ) on the side walls were given this treatment. The remainder of the structural items will also be treated when work in the forming department permits.
Often a completely permanent solution to this very difficult problem is almost unattainable, due to the consistency and heaviness of the corrosive working day. Nevertheless, TCC, who use Jenolite regularly for general maintenance work in the factory, are confident that it will provide considerable savings in labour and costs over a number of years.