The Preservation of Fishing Nets, Trawl Twines and Fibre Robes for Use in Sea Water

Publisher Website
Google Scholar
Abstract
Manila ropes and trawl twines, and cotton nets, have been immersed in clean sea water for periods up to 14 months, some with alternate wetting and drying, some wet all the time, but in both cases accompanied by storage in air after immersion. All the untreated specimens perished, but the 700 lb. manila ropes retained at least 40% of the original tensile strength.in every case in which a copper soap had been included in the treatment. A previous treatment with cutch is a considerable advantage as shown by the 500 lb. manila ropes and trawl twines, though cutch alone is worthless. Coal tar distillates after cutch are, however, more useful than when used alone, and their mixture with copper soaps gives excellent results. Cutch fixed with bichromate gives tolerably good preservation on nets up to 6 months, but is a poor preservative for trawl twines and ropes which are expected to have a long life. The choice of the copper soap used depends upon the material to be preserved. Naphthenate is the most soluble and penetrates thick ropes excellently; on fine nets it leaches out easily. Oleate is cheaper, but its penetration is less; it does very well with tar on twines and nets. Resinate is the least soluble, but is useful with creosote oil or tar. On account of their greasy nature naphthenate and oleate act as lubricants in ropes. Immersion tests on other preservatives, kindly suggested by Dr S. G. Barker, are to be begun.

This publication has 2 references indexed in Scilit: