Rubber - All You Need to Know
SINCE 1973 good rubber strip has been a problem to find. The trouble started when the chief source, the Pirelli factory near Milan, Italy was reorganized. It was split off from the Pirelli company and became part of a new company called Filati. The Pirelli company still makes the sheet rubber, which is sold to Filati who strips it to size and markets it. Beginning with the 1973 batch the Filati tested by the writer varied widely in energy storage and appearance. The old fashioned product was brown and had energy storage around 3300 foot pounds per pound. In 1973 a test of a very black Filati gave only 2250 foot pounds per pound. In 1974 a gray batch tested at an encouraging 3310, but in 1976 a batch gave 2600, and in 1977, a batch gave only 1500 foot pounds per
Rubber - All You Need to Know
IN A previous article the development of several new types of excellent quality rubber was described. Laboratory tests and field tests with models have demonstrated that these new rubber types are equivalent in quality to pre-1973 Pirelli. Since 1973, when the Pirelli company reorganized and disrupted the supply of rubber used by most contestants, there was no consistent supply of good rubber strip for model airplanes until 1976. In that year FAI rubber appeared and, a little later, Sig and Vintage Aero rubber with similar properties. In 1978 Pirelli arrived back on the scene with the new Pirelli especially made for model fliers. The new Pirelli is yellow-brown and almost translucent, whereas, the Filati is dark brown and opaque. The excellent quality of these new types of rubber according to Mike Dikovitzky has, "Put the fun back into flying rubber powered models!"
