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

Abstract

A trade waterproofing of sisal rope had still some effect after 3 days in sea water, the untreated being four-fifths saturated in 1 hr.Treating manila, sisal and coir rope with Cuprinol or tar increases the wet weight at the most only slightly as less water is taken up than without preservative.Water equilibrium is not attained till long after the B.S.I, specification test period for waterproofing sisal rope, but some effect of waterproofing may be distinguished up to perhaps 3 days.On cotton netting copper naphthenate preservatives were most durable in a clean sea-water basin, but Dr Olie's method with cutch and ammoniacal copper sulphate ran them close and is cheaper. The best lasted 9 months as against untreated 5½ months.On trawl twines the British Columbia grade of Cuprinol, a proprietary mixture containing copper naphthenate, was the best of those tried, and the twines lasted 16 months as against almost 9 for untreated manila.On thin sisal rope six copper preparations are still under test.